Monday, August 13th 2018
8:00 Opening Session I (Session chair: Xueming Yang) 8:20 – 9:00 Spectroscopy of Metal and Metal Oxide Clusters using Slow Electron Velocity-Map Imaging of Cryogenically Cooled Anions Daniel Neumark 9:00 – 9:40 Photoluminescent Metal-Containing Ions Manfred Kappes 9:40 – 10:00 Dalian Coherent Light Source-Based Infrared Spectroscopy of Neutral Clusters Ling Jiang 10:00 – 10:30 Break Session II (Session chair: Guanghou Wang) 10:30 – 11:10 Two-Dimensional Boron Sheets Kehui Wu 11:10 – 11:30 Manipulating the Magnetic Moment of Graphene-Supported Palladium Clusters by Adsorption of Hydrogen María J. López 11:30 – 11:50 Probing the Structures of Gas-Phase Boron Clusters Using Size-Selective IR Spectroscopy Andre Fielicke 11:50 – 12:10 Ab Initio Global Search of Pure and Metal-Doped Boron Clusters Jijun Zhao 12:10 – 13:30 Lunch Session III (Session chair: Julio Alonso) 13:30 – 14:10 When Not only Each Atom Counts! Ulrich Heiz 14:10 – 14:50 From Single-Atom Catalysis (SAC) to Single-Cluster Catalysis (SCC) Jun Li
14:50 – 15:10 Activation and Reactions of Small Molecules (O2, NO, CO, C2H4, etc.) on IB Group (Cu, Ag, and Au) Metal Clusters Xiao-Peng Xing 15:10 – 15:30 Successive Nitridation of Tantalum Cluster Cations by Ammonia Molecules: The Origin of Bulk- Nitride Composition of Group 5 Metals Masashi Arakawa 15:30 – 16:00 Break Session IV (Session chair: Chuan-Gang Ning) 16:00 – 16:40 Infrared and Velocity-Map Imaging Studies of Decorated Metal Clusters and Metal-Ligand Complexes Stuard Mackenzie 16:40 – 17:20 Infrared Spectroscopy of Donor-Acceptor Bonding Carbonyl Complexes Mingfei Zhou 17:20 – 17:40 The Effect of Radiative Cooling on the Size-Dependent Stability of Small Boron Clusters Piero Ferrari 17:40 – 18:00 Bilayer Fullerenes Studied by Ion Mobility Mass Spectrometry Motoyoshi Nakano
Monday August 13th INV1
Spectroscopy of metal and metal oxide clusters using slow electron velocity-map imaging of cryogenically cooled anions
Daniel Neumark1
1 University of California at Berkeley, USA
Slow electron velocity-map imaging of cryogenically cooled anions (cryo-SEVI) is a high resolution variant of negative ion photoelectron spectroscopy. It yields well-resolved spectra of species that were previously found to be spectroscopically intractable using lower resolution techniques. Results will be presented for transition metal oxide clusters, aluminum clusters, and mixed carbon/silicon clusters. The effects of complexation of water will also be considered, with the goal of elucidating whether water is physisorbed or dissociatively chemisorbed.
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China
Monday August 13th INV2
Photoluminescent Metal-Containing Cluster Ions
Manfred M. Kappes1,2
1 Institute of Physical Chemistry, KIT, Karlsruhe, Germany
2 Institute of Nanotechnology, KIT, Karlsruhe,
Isolated ionic clusters held together mainly by Coulomb interactions have been of interest to cluster science since before ISSPIC-I. Over the years, system complexity has evolved from alkali halide clusters to experimentally more demanding metal-organic aggregates thus also making contact to mainstream chemistry. Advancements in mass spectrometry and associated hybrid methods have made this possible --- driven to a significant degree by technology developed in the cluster community. This talk will discuss recent work on photoluminescent metal-organic aggregates containing transition or lanthanoid metal ions. We have studied them after electrospray ionization - using high resolution ion mobility spectrometry, trapped ion photoluminescence spectroscopy and time-resolved photoelectron spectroscopy [1-3]. Whereas the emission spectroscopy of isolated cationic luminophores can be readily probed (and compared to solution), this is not the case for multianionic systems. Instead of strong photoluminescence as in condensed phase, these species undergo excited state electron tunneling detachment (ESETD). The competing mechanisms will be discussed and explained.
[1] M.-O. Winghart, J.-P. Yang, M. Vonderach, A.-N. Unterreiner, D.-L. Huang, L.-S. Wang, S. Kruppa, C. Riehn and M. Kappes, J. Chem. Phys., 144, 054305 (2016) [2] J.-F. Greisch, J. Chmela, M. E. Harding, D. Wunderlich, B. Schaefer, M. Ruben, W. Klopper, D. Schooss and M. Kappes, Phys. Chem. Chem. Phys., 19, 6105 (2017) [3] J. Chmela, J.-F. Greisch, M. E. Harding, W. Klopper, M. Kappes and D. Schooss, J. Phys. Chem. A, 122, 2461 (2018)
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China
Monday August 13th HT1
Dalian Coherent Light Source-Based Infrared Spectroscopy of Neutral Clusters
Ling Jiang
State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, China
E-mail: [email protected]
Dalian Coherent Light Source (DCLS) delivers the Vacuum Ultraviolet Free Electron Laser (VUV-FEL) with high brightness and ultrafast laser pulses in the 50-180 nm wavelength region in picoseconds or 100 femtoseconds, which is an ideal light source for the ionization of molecular systems and the excitation of valence electrons with very high efficiency. DCLS is operated in the mode of High Gain Harmonic Generation (HGHG), which is beneficial to narrow bandwidth, stable power, and low cost due to fewer undulators. The VUV-FEL power for individual pulse at 133 nm approached more than 200 microJoules. The user experiment started in June, 2017. It is open for good proposals from the whole world. In this talk, we will present the commission and main specifications of DCLS, and the first experiment of DCLS- based infrared spectroscopy of neutral water clusters.
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Monday August 13th INV3
Two-dimensional boron sheets
Kehui Wu
Institute of Physics, Chinese Academy of Sciences
Seeking for low-dimensional boron allotropes has attracted considerable interest in the past decades and theoretical works predicted the existence of 2D boron sheets (or namely borophene). As boron has only three valence electrons, the electron deficiency makes a honeycomb lattice of boron energetically unstable. Instead, a triangular lattice with periodic holes was predicted to be more stable. In 2015, we successfully synthesized 2D boron sheets on silver surface, which host triangular lattice with different arrangements of hexagonal holes [1,2]. An intriguing question is whether it is possible to prepare a borophene monolayer with a pure honeycomb lattice. Honeycomb borophene will naturally host Dirac fermions and thus intriguing electronic properties resembling other group IV elemental 2D materials. Recently, We reported the successful preparation of a purely honeycomb, graphene-like borophene, by using an Al(1 1 1) surface as the substrate and molecular beam epitaxy (MBE) growth in ultrahigh vacuum. Scanning tunneling microscopy (STM) images reveal perfect monolayer borophene with planar, non-buckled honeycomb lattice similar as graphene. Theoretical calculations show that the honeycomb borophene on Al(1 1 1) is energetically stable. Remarkably, nearly one electron charge is transferred to each boron atom from the Al(1 1 1) substrate and stabilizes the honeycomb borophene structure [3]. This work demonstrated that one can manipulate the borophene lattice by controlling the charge transfer between the substrate and the borophene. And the honeycomb borophene provides attractive possibility to construct boron-based atomic layers with unique electronic properties such as Dirac states, as well as to control superconductivity in boron-based compounds.
Figure 1. High resolution STM images of honeycomb borophene monolayer on Al(1 1 1). (a) STM image (15 nm × 15 nm) showing the large- period, triangular corrugation. (b) A high resolution STM image (2.4 nm × 2.4 nm) of the area marked by black rectangle in (a), showing a flat honeycomb lattice. (c) 3D STM image (4 nm × 4 nm) of the area marked by white rectangle in (a). The scanning parameters for (a-c) are: sample bias −11 mV, I = 130 pA.
References: [1] B. J. Feng et al. Nat. Chem. 8, 563(2016) [2] B. J. Feng et al. Phys. Rev. Lett. 118, 096401 (2017) [3] W. B. Li et al. Sci. Bull. 5, 282(2018)
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Monday August 13th HT2
Manipulating the magnetic moment of graphene-supported palladium clusters by adsorption of hydrogen
María J. López1, María Blanco-Rey2,3, J. Iñaki Juaristi4,3, Maite Alducin4,2,3, Alejandra Granja-DelRío1, Julio A. Alonso1,3
1 Departamento de Física Teórica, Atómica y Óptica, Universidad de Valladolid, Spain 2 Centro de Física de Materiales CFM/MPC (CSIC-UPV/EHU), Donostia-San Sebastián, Spain. 3 Donostia International Physics Center (DIPC), Donostia-San Sebastián, Spain 4 Departamento de Física de Materiales, Facultad de Químicas UPV/EHU, Donostia-San Sebastián, Spain [email protected] The catalytic activity of transition metal (TM) clusters and nanoparticles supported on carbonaceous materials towards the dissociation of molecular hydrogen in two hydrogen atoms plays a key role in a variety of technological applications such as hydrogenation reactions, hydrogen fuel cells, hydrogen storage, etc. Therefore understanding the mechanisms and effects of hydrogen adsorption on supported TM clusters is of basic and practical interest. With this purpose, we have studied the interaction of hydrogen with palladium clusters supported on graphene [1,2]. There is a sizable probability for the dissociation of H2 deposited at low energy on the Pd clusters. Interestingly, the dissociation of hydrogen is accompanied by a total or partial quenching of the magnetic moment of the cluster. To unravel the interplay between these two physical processes, magnetization change and molecular dissociation, we have performed static calculations and ab initio molecular dynamics simulations [3,4] within the framework of the density functional formalism. The effect of H2 dissociation is to reduce the magnetic moments of supported Pdn (n=3-6, 13) clusters by about 2 μB (see Figure 1). The quenching of the magnetic moments occurs at different stages (before or after dissociation) of the reaction depending on the cluster size, and it can be correlated with: i) the magnetic moment of the species with hydrogen adsorbed in the molecular form, and ii) with the energy barriers for dissociation. The results suggest that adsorption and dissociation of H2 can be viewed as an effective tool to manipulate the magnetic state of clusters and nanoparticles supported on carbonaceous substrates, which could lead to interesting applications in devices.
4 P 2 P 2 P B B B
Figure 1: spin density difference (ρup – ρdown) of Pd13, H2@ Pd13, and 2H@ Pd13 supported on a graphene layer. The green isosurfaces correspond to excess of spin up electrons.
[1] Cabria, I.; López, M. J.; Fraile, S.; Alonso, J. A. J. Phys. Chem. C 2012, 116, 21179–21189. [2] Granja, A.; Alonso, J. A.; Cabria, I.; Lopez, M. J. RSC Adv. 2015, 5, 47945–47953. [3] Blanco-Rey, M.; Juaristi, J. I.; Alducin, M.; López, M. J.; Alonso, J. A. The Journal of Physical Chemistry C 2016, 120, 17357–17364. [4] López, M. J.; Blanco-Rey, M.; Juaristi, J. I.; Alducin, M.; Alonso, J. A. The Journal of Physical Chemistry C 2017, 121, 20756−20762.
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China
Monday August 13th HT3
Probing the structures of gas-phase boron clusters using size-selective IR spectroscopy
1,2 1,2 1,2 2 M. R. Fagiani , X. Song , S. Debnath , K. R. Asmis , A. Günther1, W. Schöllkopf1, G. Meijer1, A. Fielicke1
1Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany 2 Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstrasse 2, 04103 Leipzig, Germany
Pure boron clusters are predicted to exhibit a wide range of structural motives from planar structures, double layered rings to cages. So far, most detailed insights for their structures comes from anion photoelectron spectroscopy in combination with quantum chemical calculations.[1]
Infrared spectroscopy provides an alternative sensible probe of the molecular structure, however, classical absorption spectroscopies are difficult to be applied to gas-phase clusters that are typically produced in a wide size distribution at low number densities. Therefore, in the last years techniques have been developed that couple high sensitivity with size selectivity by detecting the absorption of IR photons via changes in mass spectra. For cationic boron clusters IR spectra are obtained by photodissociation of cold messenger complexes with Kr in a cryogenic ion trap mass spectrometer.[2] By comparison with spectra obtained from density + + + functional theory planar structures can be unambiguously assigned to B39 , B40 , and B41 . While these isomers appear to be not the global minima at low temperature, their presence can be understood by a cluster growth at finite temperature.
IR spectra of neutral boron clusters have been obtained in the past via an IR-UV two color ionization scheme. However, this technique is limited by the availability of UV laser sources that need to closely match the ionization energy of the clusters to be studied. Using an F2 laser
(hν=7.9 eV) IR spectra only of B11, B16, and B17 have been obtained.[3] We are now combining a 4-wave mixing VUV generation setup that covers the 6-9 eV range with the cluster mass spectrometer to cover a wider mass range and in particular to study clusters around n=40 where the presence of stable boron cages has been suggested.[4]
[1] L.-S. Wang, Int. Rev. Phys. Chem. 35 (2016) 69. [2] M.R. Fagiani, X. Song, P. Petkov, S. Debnath, S. Gewinner, W. Schöllkopf, T. Heine, A. Fielicke, K.R. Asmis, Angew. Chem. Int. Ed. 56 (2017) 501. [3] C. Romanescu, D.J. Harding, A. Fielicke, L.-S. Wang, J. Chem. Phys. 137 (2012) 014317. [4] H.-J. Zhai, Y.-F. Zhao, W.-L. Li, Q. Chen, H. Bai, H.-S. Hu, Z.A. Piazza, W.-J. Tian, H.-G. Lu, Y.-B. Wu, Y.-W. Mu, G.-F. Wei, Z.-P. Liu, J. Li, S.-D. Li, L.-S. Wang, Nat Chem 6 (2014) 727.
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Monday August 13th HT4
Ab initio global search of pure and metal-doped boron clusters
Jijun Zhao1
1 Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, Dalian 116024, China
Using ab initio based global search with simulated annealing method or genetic algorithm, we have determine the lowest-energy structures of boron clusters with n = 28, 46, 48, 50, 68, 74,
80, 101 [1-4]. We have found the smallest all-boron cage at B28. For larger clusters with n t 68, core-shell structural motif is dominant. In the intermediate size range, a core-shell
B4@B42 structure, an unprecedented bilayer structure, and a quasi-planar configuration with
two connected hexagonal holes, are found for B46, B48, and B50, respectively. Furthermore,
the bilayer structure at B48 inspires the most stable phase for bilayer boron sheet [5]. Finally, we have searched the lowest-energy structures of Mo-doped boron clusters and identified a
novel superatom at Mo@B22 with high stability and large HOMO-LUMO gap [6].
[1] J. Zhao, et al., J. Phys. Chem. A 114, 9969 (2010). [2] F. Y. Li, et al., J. Chem. Phys. 136, 074302 (2012). [3] J. Zhao, et al., Nanoscale 7, 15086 (2015). [4] L. Sai, et al., Nanoscale 9, 13905 (2017). [5] N. Gao, et al., FlatChem 7, 48 (2018). [6] Y. Wang, et al., J. Clust. Sci. (2018), DOI: 10.1007/s10876-018-1369-3.
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Monday August 13th INV4
When not only each atom counts!
F. Esch, U. Heiz, A. Kartouzian, B. Lechner, M. Tschurl Institute of Physical Chemistry, Catalysis Research Center, Technical University Munich [email protected] Clusters reveal exciting intrinsic properties that vary strongly with size. When in contact with a chemical environment or interacting with e.g. electromagnetic fields the chemical behavior of the clusters can drastically alter and new functionalities may even evolve. Several examples are presented to illustrate these effects, ranging from free clusters in the gas phase, cluster in contact with solid surfaces and chiral molecular layers, clusters in the liquid phase to clusters interacting with electromagnetic fields. Small free cationic clusters comprising fewer than five tantalum atoms mediate the dehydrogenation of methane and concomitant elimination of dihydrogen. Modeling facilitates the kinetic and mechanistic characterization of the reaction, where we focus on the C–H bond activation of methane. The effect of cluster size and the properties of tantalum cluster oxides with a specific number of oxygen atoms are discussed. [1] In a second example, we present results on the hydrogenation of ethylene on Ptn clusters, where we observed an onset of reactivity when going from Pt9 to Pt10. Pt13 or Pt14 are the most active cluster sizes when interacting with MgO or amorphous SiO2, respectively. The origin of the size dependent reactivity is the local charging of the reactive atoms in the cluster [2], which can be modulated by changing support acidity, support stoichiometry and support doping. [3,4] When in contact with chiral molecular surfaces chirality can be induced into the small clusters, making them ideal asymmetric catalysts. Here we show how we can detect this chirality transfer by employing a new toolbox of surface sensitive chiroptical spectroscopic techniques. [5] Finally the complex molecular mechanism of alcohol reforming on metal cluster-semiconductor hybrid materials under irradiation is discussed. A hole mediated disproportionation reaction is revealed to be a new photocatalytic reaction mechanism for hydrogen evolution from methanol and other alcohols. The role of the metal co-catalyst in this reaction is the dehydroxylation of the semiconductor surface. Furthermore, it is demonstrated how the selectivity of photocatalytic reactions is influenced by temperature, which is often neglected in many studies. [6] [1] Eckhard, J.F., et. al., Phys.Chem.Chem. Phys. 19(17), 2017, 10863-10869 [2] Crampton, A., et. al.; Nature Communications, 2016, 10389 [3] Crampton, A. et. al., ACS Catalysis, 7(10), 2017, 6738-6744 [4] Crampton, A., et.al., Angewandte Chemie Int. Ed. 55(31), 2016, 8953-8957 [5] Santoro, F., et.al., ChemPhysChem, 19(6), 2018, 715-723 [6] Walenta C., et. al., Phys.Chem.Chem.Phys. 20(10), 2018, 7105-7111
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China
Monday August 13th INV5
From Single-Atom Catalysts (SAC) to Single-Cluster Catalysts (SCC)
Jun Li ( )*
Theoretical Chemistry Center, Department of Chemistry, Tsinghua University, Beijing 100084, China
*E-Mail: [email protected]
Catalysis science is essential for chemical industries, biological transformation, atmospheric processes, environment, energy, and human health. In recent years, research on single-atom catalysts (SACs) has become a new frontier in heterogeneous catalysis [1]. As a bridge of homogeneous catalysis and heterogeneous catalysis, SACs have provided enormous opportunities for rational design of innovative catalysts with remarkable performance in a variety of applications. Through recent ab initio molecular dynamics (AIMD) simulations of
Au20/TiO2 and Au20/CeO2 nanocatalysts, we find that the microscopic mechanisms of a series of catalytic reactions of nanoclusters involve dynamic single-atom catalysts (DSACs) [2]. We also recently extended the SAC concept to single-cluster catalysts (SCC) on heterogeneous surfaces and demonstrated their extensive advantages and superb performance in catalyzing N2-to-NH3 and NO+CO conversions [3]. In this talk, we will provide an overview of the theoretical aspects of selected SACs, dynamic SACs, and SCCs to shed light on the promising potential of developing exactly tunable active centers via chemistry approaches.
References: [1] (a) B. Qiao, A. Wang, X. Yang, L. F. Allard, Z. Jiang, Y. Cui, J. Liu, J. Li, T. Zhang, "Single-Atom Catalysis
of CO Oxidation Using Pt1/FeOx", Nature Chem. 2011, 3, 634 641. (b) X. Yang, A. Wang, B. Qiao, J. Li, J. Liu, T. Zhang, "Single-Atom Catalysts: A New Frontier in Heterogeneous Catalysis", Acc. Chem. Res. 2013, 46, 1740-1748. (c) A. Wang, J. Li, T. Zhang, " Heterogeneous Single-Atom Catalysis", Nat. Rev. Chem. 2018, 2, 65-81. [2] (a) Y.-G. Wang, Y. Yoon, V.A. Glezakou, J. Li, R. Rousseau, "The Role of Reducible Oxide-Metal Cluster Charge Transfer in Catalytic Processes: New Insights on the Catalytic Mechanism of CO Oxidation on
Au/TiO2 from Ab Initio Molecular Dynamics", J. Am. Chem. Soc. 2013, 135, 10673-10683. (b) Y.-G. Wang, D. Mei, V.-A. Glezakon, J. Li, R. Rousseau, "Dynamic Formation of Single-Atom Catalytic Active Sites on Ceria-Supported Gold Nanoparticles", Nature Commun. 2015, 6, 6511. (c) J.-C. Liu, Y.-G. Wang, J. Li, "Toward Rational Design of Oxide-Supported Single Atom Catalysts: Atomic Dispersion of Gold on Ceria", J. Am. Chem. Soc. 2017, 139, 6190-6199. (c) Y. He, J.-C. Liu, L. Luo, Y.-G. Wang, J. Zhu, Y. Du, J. Li, S. X. Mao, C. Wang, "Size-Dependent Dynamic Structures of Supported Gold Nanoparticles under CO Oxidation Reaction Condition", Proc. Natl. Acad. Sci., USA 2018, 115, in press. [3] (a) S. Zhang, L. Nguyen, J.-X. Liang, J. Shan , J. Liu, A. I. Frenkel, A. Patlolla, W. Huang, J. Li, F. Tao, "Catalysis on Singly Dispersed Bimetallic Sites", Nature Commun. 2015, 6, 7938. (b) X.-L. Ma, J.-C. Liu, H.
Xiao, J. Li, "Surface Single-Cluster Catalyst for N2-to-NH3 Thermal Conversion", J. Am. Chem. Soc. 2018,
140, 46-49. (c) J.-C. Liu, X.-L. Ma, Y. Li, Y.- 3 single-cluster catalyst for ammonia synthesis via an associa Nature Commun. 2018, 9, 1610.
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China
Monday August 13th HT5
Activation and Reactions of Small Molecules (O2, NO, CO, C2H4, etc.) on IB Group (Cu, Ag, and Au) Metal Clusters
1 1 1 1 1 X. Xing , J. Ma , B. Yin , T. Wang , J. Yang
1School of Chemical Science and Engineering, Tongji University, China
We explored activation and reactions of O2, NO, CO, C2H4, etc. on IB group (Cu, Ag, and Au) metal clusters using a flow reactor running at low temperatures. The adsorption of O2 or NO on - - Agn and Aun in the 0-1 nm size range is strongly dependent on the global electronic properties of these metal moieties, while marginally related to their local structures or adsorption sites [1- 3]. We observed the formation of NO trimer on anionic gold, the disproportionation reactions of - - NO on Au6 and Au20 whose mechanism involving three NO molecules [4], the generation of - free or chemisorbed CO2 in the reactions between CO and AgnO [5] and the distinctive - - - reactions of AgOn with CO, NO and C2H4 which are different from those of CuOn and AuOn . In combination with DFT calculations, these experimental observations were well interpreted, and shed new light on related elementary processes in the real catalytic systems.
Figure 1: The flow reactor running at low temperatures combined with a magnetron sputtering cluster source and a TOF.
[1] Ma, J.; Cao, X.; Xing, X.; Wang, X.; Parks, J. Adsorption of O2 on anionic silver clusters: spins and electron binding energies dominate in the range up to nano sizes. Phys. Chem. Chem. Phys. 18, 743-748 (2016). [2] Wang, T.; Ma, J.; Yin, B.; Xing, X. Adsorption of O2 on anionic gold clusters in the 0 – 1 nm size range: an insight into the electron transfer dynamics from kinetic measurements. J. Phys. Chem. A 122, 3346-3352 (2018). [3] Ma, J.; Cao, X.; Hao, L.; Baoqi, Y.; Xing, X., Adsorption and activation of NO on silver clusters with sizes up to one nanometer: interactions dominated by electron transfer from silver to NO. Phys. Chem. Chem. Phys. 18, 12819-12827 (2016). – [4] Ma, J.; Cao, X.; Chen, M.; Yin, B.; Xing, X.; Wang, X. Low-temperature disproportionation reaction of NO on Au6 : a mechanism involving three NO molecules promoted by the negative charge. J. Phys. Chem. A 120, 9131-9137 (2016). [5] Cao, X.; Chen, M.; Ma, J.; Yin, B.; Xing, X., CO oxidation by the atomic oxygen on silver clusters: structurally dependent mechanisms generating free or chemically bonded CO2. Phys. Chem. Chem. Phys. 19, 196-203 (2017).
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Monday August 13th HT6
Successive nitridation of tantalum cluster cations by ammonia molecules: The origin of bulk-nitride composition of group 5 metals
M. Arakawa,1 K. Ando,1 S. Fujimoto,1 S. Mishra,2 G. Naresh Patwari,2 A. Terasaki1 1 Department of Chemistry, Faculty of Science, Kyushu University, Japan
2 Department of Chemistry, Indian Institute of Technology Bombay, India [email protected] Tantalum nitride is an attractive material with a potential for various applications, e.g., copper diffusion barriers in microelectronics, an interlayer in magnetic random access memories, and photocatalysts for H2 evolution. Elucidation of nitridation mechanism of tantalum at the molecular level would supply a useful recipe for fabricating high-quality tantalum-nitride materials. In this context, gas-phase clusters provide an ideal approach to probe reactions step by step with precise control in the number of atoms and molecules involved in a reaction [1,2]. + + In the present study, nitridation of free tantalum cation, Ta , and tantalum cluster cations, Tan , by ammonia molecules is investigated [3], since it is known that nitridation does not proceed by nitrogen molecules [4]. + In the experiment, Tan (n = 1–10) was generated by a magnetron-sputter cluster-ion source. They were mass-selected and guided into a reaction cell filled with NH3 molecules. The ions produced by the reaction were identified by a quadrupole mass analyzer + The reaction of monomer cation, Ta , with two molecules of NH3 leads to formation of + TaN2H2 along with release of two H2 molecules. The dehydrogenation occurs until the formal oxidation number of the tantalum atom reaches +5. On the other hand, all the tantalum cluster + + cations, Tan , react with two molecules of NH3 and form TanN2 with the release of three H2 + + molecules. Further exposure to ammonia showed that TanNmH and TanNm are produced through successive reactions; a pure nitride and three H2 molecules are formed for every other NH3 molecule. The nitridation occurred until the formal oxidation number of tantalum atoms + reaches +5 as in the case of TaN2H2 . These reaction pathways of tantalum atom and cluster cations are in contrast to those of other group 5 elements, i.e., vanadium and niobium cluster cations, which have been reported to produce nitrides with lower oxidation states [5,6]. The present results on nitridation of small clusters illustrate correlation with their bulk properties: Tantalum is known to form bulk nitrides in the oxidation states of either +5 (Ta3N5) or +3 (TaN), whereas vanadium and niobium form only an oxidation state of +3 (VN and NbN) [7]. Along with DFT calculations, these findings reveal that electronegativity of the metal (V > Nb> Ta) plays a key role in determining the composition of metal nitrides. In contrast to nitrides, all of vanadium, niobium and tantalum form most stable oxides in the oxidation state of +5 due to high electronegativity of oxygen compared with nitrogen. The present study thus revealed that electronegativity of group 5 metal is crucial for nitridation.
[1] M. Arakawa, R. Yamane, A. Terasaki, J. Phys. Chem. A 120, 139 (2016). [2] M. Arakawa, T. Omoda, A. Terasaki, J. Phys. Chem. C 121, 10790 (2017). [3] M. Arakawa, K. Ando, S. Fujimoto, S. Mishra, G. Naresh Patwari, A. Terasaki, Phys. Chem. Chem. Phys., in press. [4] F. Mafuné, Y. Tawaraya, S. Kudoh, J. Phys. Chem. A 120, 4089 (2016). [5] S. E. Kooi, A. W. Castleman, Jr., Chem. Phys. Lett. 315, 49 (1999). [6] S. Hirabayashi, M. Ichihashi, Int. J. Mass Spectrom. 407, 86 (2016). [7] D. H. Gregory, J. Chem. Soc., Dalton Trans., 259 (1999).
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Monday August 13th INV6
Infrared and velocity map imaging studies of decorated metal clusters and metal- ligand complexes
A.S. Gentleman1, A. Iskra,1 E.M. Cunningham,1 A.S. Green,1 A. Fielicke2, and S.R. Mackenzie1
1Physical and Theoretical Chemistry Laboratory, University of Oxford, U.K.
2Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany.
For decades, small isolated metal clusters and metal–ligand complexes have been proposed as tractable model systems for heterogeneous catalysis. Certainly, gas–phase clusters provide idealized environments for the study fundamental interactions which may lead to a better understanding of the reactive pathways involved.
Our laboratory has taken a multi–faceted approach to studying different parts of the reactive potential energy surface, with infrared spectroscopy used to probe pre–reactive (entrance– channel) complexes and velocity map imaging recording final quantum–state distributions.
In this talk, we will present results from recent (and indeed ongoing) studies investigating a diverse range of systems including:
– x Size-selective CO2 activation on anionic platinum clusters, Ptn x N2O binding and activation at individual metal– and metal–oxide centres x Size– and charge–selective CO activation on mixed–metal “nano-alloy” clusters
In all cases, interpretation of the experimental data is only possible by comparison with the results of quantum chemical calculations which shed light on details of the reactive free- energy surface and trapping of excited states.
– Figure 1: a) FEL IR-MPD spectra of [Pt4CO2] showing exclusively molecularly bound CO2 despite the putative global minimum structure being fully dissociated. b) The structure shows the CO2 to be strongly activated.
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China
Monday August 13th INV7
Infrared Spectroscopy of Donor-Acceptor Bonding Carbonyl Complexes
Mingfei Zhou
Department of Chemistry, Collaborative Innovation Center of Chemistry for Energy Materials, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200433, China. E-mail: [email protected]
Transition metal carbonyls are the cornerstones of modern organometallic chemistry and serve as textbook examples in illustrating metal-ligand bonding and the electron counting rules.
Adducts like Cr(CO)6, Fe(CO)5 and Ni(CO)4 are prototypical examples for illustrating the Dewar-Chatt-Duncanson bonding model involving the dichotomy of σ donation and π backdonation between the transition metal and the ligand and the associated filling of the valence orbitals of the metal. This talk will present our recent results on the preparation of a number of neutral and charged highly coordinated transition metal as well as main group metal carbonyl complexes either in gas phase or in solid noble gas matrices, which are studied using infrared photodissociation spectroscopy and matrix isolation infrared absorption spectroscopy. Vibrational spectroscopic combined with state-of-the-art quantum chemical calculations unrevealed unusual structure and bonding properties of these carbonyl complexes, demonstrating that the carbonyl ligands known for 150 years, are still capable of producing surprises.
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Monday August 13th HT7
The effect of radiative cooling on the size-dependent stability of small boron clusters
P. Ferrari1, J. Vanbuel1, K. Hansen2,1, P. Lievens1, E. Janssens1, A. Fielicke3 1 Department of Physics and Astronomy, KU Leuven, Belgium 2 Department of Physics, Tianjin University, China 3 Fritz-Haber-Institut der Max-Planck-Gesellschaft, Germany [email protected] Small boron clusters have received significant attention the last years. The peculiar bonding mechanism of boron clusters leads, among other features, to unique ground-state structures [1], fluxionality [2] and highly non-trivial stability patterns [3]. Previous studies have shown, + forexample, an enhanced stability of the B13 cluster [3]. Clusters with a high stability are most likely to retain their integrity when deposited on surfaces, which is of prime importance for applications. The stability of clusters is usually investigated mass spectrometrically by exciting distributions of clusters and analyzing the relative intensity of the fragmentation products. In the interpretation of this type of experiments, one often neglects the possibility of alternative cooling channels, in particular radiative cooling. However, recent experiments have shown that several kinds of photo-excited clusters can cool radiatively, in some cases at high rates [4,5]. This has serious implications for both the production of particles and the quantitative understanding of their size-dependent stabilities. In this presentation we show that radiative cooling is crucial when analyzing size-to-size stabilities by investigating, as a representative case, small cationic boron clusters. Combining the experimental information of mass spectra intensities, radiative cooling rates and fragmentation channels, stability patterns were quantified by the ratio of dissociation energies ܦܰΤܦܰͳ. As shown in Figure 1, these ratios agree with DFT calculations, but only if radiation is taken into account in the analysis.
Figure 1: Ratio of dissociation energies extracted from the experiment. The analysis with and without radiative cooling is shown, together with values from DFT calculations in Ref. [6].
[1] H.-J. Zhai et al., Nat. Chem. 6, 727 (2014). [2] M. Fagiani et al., Angew. Chem. Int. Ed. 56, 501 (2017). [3] L. Hanley et al., J. Phys. Chem. 92, 5803 (1988). [4] K. Hansen et al., Phys. Rev. A 95, 022511 (2017). [5] P. Ferrari et al, J. Chem. Phys. 143, 224313 (2015). [6] T. B. Tai et al., Theor. Chem. Acc. 131, 1241 (2012).
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China
Monday August 13th HT8
Bilayer fullerenes studied by ion mobility mass spectrometry
1,2 2 2 2 2,3 M. Nakano , R. Moriyama , J. W. J. Wu , K. Ohshimo , F. Misaizu
1 Institute for Excellence in Higher Education/Tohoku University, Japan
2 Department of Chemistry, Graduate School of Science/Tohoku University, Japan
3 New Industry Creation Hatchery Center/Tohoku University, Japan
± Carbon cluster ions, Cn , grow and increase in size (n < 100) from linear to two-dimensional cyclic, and then to cage-like structures. In contrast, nanometer-scale carbon materials form various structures. In this study, structural isomers of carbon cluster cations in the intermediate z+ size range between cluster and nanoparticle (Cn , n = 100 – 800) have been investigated by ion mobility mass spectrometry to discuss the growth process [1]. In the experiments, carbon cluster ions generated by laser vaporization and supersonic expansion were injected into an ion-drift cell filled with 3.0-Torr He buffer gas. The ions reached a constant drift velocity with a balance of acceleration with an applied electrostatic field and deceleration by collisions with He in the ion-drift cell. Thus, the ions exited the cell with different “arrival time” depending on their charge and collision cross section (CCS). Finally, the ions were analyzed by a reflectron type time-of-flight mass spectrometer. As shown in Figure 1, bilayer fullerene monocation series were observed as continuous distribution for n = 260 – 700. The difference in the slope of monolayer and bilayer cation series indicates that the inner layer fullerene does not maintain specific structure such as the stable fullerene C60, instead, it grows as the outer layer grows. According to the ratio of the + slopes, the inner and outer fullerene layer structure for n = 260 was [C30@C230] , 300 was + + [C40@C260] , 600 was [C120@C480] , and so on. The smallest bilayer fullerene at n ≈ 260 was reasonable from the fact that the inner layer of C30 was the smallest fullerene observed in this study and in a previous one [2].
Figure 1: 2D spectrum of carbon cluster cations measured by ion mobility mass spectrometry.
[1] R. Moriyama, J. W. J. Wu, M. Nakano, K. Ohshimo, F. Misaizu, J. Phys. Chem. C 122, 5195 (2018). [2] N. G. Gotts, G. von Helden, M. T. Bowers, Int. J. Mass Spectrom. 149/150, 217 (1995).
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China
Tuesday, August 14th 2018
Session V (Session chair: Ignacio Garzon) 8:00 – 8:40 Gold Nanocages: A Multifunctional Platform for Nanomedicine and Beyond Younan Xia 8:40 – 9:20 Control of Photo- and Electro-Generated Excited States of Colloidal Quantum Dots Xiaogang Peng 9:20 – 9:40 Toward Programmable Synthesis of Atom-precise and Multimetallic Clusters Takane Imaoka
9:40 – 10:00 Cubic Aromaticity from Multicenter-Bonded [MI]8 (M = Zn, Mn) Cluster Hanshi Hu 10:00 – 10:30 Break Conference Photo Session VI (Session chair: Si-Dian Li) 10:30 – 11:10 How Shape Changes Alter Physico-Chemical Properties of Nanoparticles Francesca Baletto 11:10 – 11:30 Molecular Beam Study of the CO Oxidation on Regular Arrays of Pd Clusters Claude Henry 11:30 – 11:50 High Throughput and Rational Design of Transition Metal Cluster Catalyst Daojian Cheng 11:50 – 12:10 Enriching Silver Nanocrystals with a Second Noble Metal Dong Qin 12:10 – 13:30 Lunch Memorial Session in Honor of Prof. Castleman and Prof. Kaya (Session chair: Richard Palmer) 13:30 – 14:10 Memorial Lecture for Albert Welford Castleman, Jr: Pioneer of Cluster Science Opening New Research Directions for the Future Vlasta Bonacic-Koutecky 14:10 – 14:50 Memorial Lecture for Koji Kaya: Superatom Periodic Table of Caged Nanoclusters Atsushi Nakajima 14:50 – 15:10 Monolayer-Protected Clusters: Structurally Precise Building Blocks for Spintronic Applications Kenneth Knappenberger 15:10 – 15:30 Hydride-doped Gold Superatoms: Synthesis, Structure and Transformation Tatsuya Tsukuda 15:30 – 16:00 Break Session VIII (Session chair: Thomas MКller) 16:00 – 16:40 Highly Charged Ions from Intense Laser-cluster Interactions Revisited Thomas Fennel 16:40 – 17:00 Single-Center Iron(VII) Trioxide Clusters: Iron in the Remarkable +7 Oxidation State Tobias Lau 17:00 – 17:20 Exploring the Surface Energy and Surface Stability of Ag Nanocrystals: An In-situ TEM Method Longbing He 17:20 – 17:40 Photoelectron Spectroscopy and Theoretical Investigate of Transition Metal-Doped Semiconductor Clusters Weijun Zheng 18:00 – 20:00 Poster Session A
Tuesday August 14th INV8
Gold nanocages: A multifunctional platform for nanomedicine and beyond
Y. Xia
The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, United States
Although gold (Au) probably should not be considered as a biomaterial, its nanostructures have been applied to a variety of biomedical applications owning to their unique properties, including bio-inertness, photoluminescence, radioactivity (for 198Au and 199Au), and strong plasmonic resonance (scattering and absorption of light) tunable to the near-infrared region. Over the past decades, many methods have been developed for producing Au nanomaterials in the quality, quantity, and reproducibility required for a systematic study of their properties as a function of size, shape, and structure, and for the full exploration of their applications in biotechnological and medical fields. In this talk, I will briefly discuss some of the recent developments, with a focus on the rational design and controlled synthesis of gold nanocages for optical imaging, drug delivery, and cancer theranostics, as well as for photothermal heating and solar energy conversion/harvesting.
[1] Yang, X.; Yang, M.; Pang, B.; Xia, Y. “Gold nanomaterials at work in biomedicine”, Chem. Rev. 2015, 115, 10410. [2] Shen, S.; Zhu, C.; Huo, D.; Yang, M.; Xue, J. and Xia, Y. “A hybrid nanomaterial for the controlled generation of free radicals and oxidative destruction of hypoxic cancer cells”, Angew. Chem. Int. Ed. 2017, 56, 8801.
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Tuesday August 14th INV9
Control of Photo- and Electro-generated Excited States of Colloidal Quantum Dots
Xiaogang Peng
Center for Chemistry of Novel & High-Performance Materials, Department of Chemistry, Zhejiang University, Hangzhou 310027, China
E-mail: [email protected]
Quantum dots as solution-processible photo- and electro-excited emitters are promising and may impact many industrial sectors. Some industrial applications of quantum dots are in place in the recent years but it is far below their anticipated potential. Both photoluminescence and electroluminescence are based on generation and relaxation of the excited states. Thus, properties of excited states should be the key for design, synthesis, understanding, and applications of emitters. Specifically, as promising emissive materials, colloidal quantum dots rely heavily on their excited-state properties, instead of solely the ground-state properties. Realization of ideal excited states should be the optimal goal for synthesis of colloidal quantum dots.
Biography Xiaogang Peng is currently a professor at Zhejiang University in China. He was a chair professor at the University of Arkansas before moving back to China in 2009. He received his B.S. (1987) and Ph.D. (1992) from Jilin University, China. His Postdoctoral experience followed by a position as Staff Scientist at UC Berkeley with Professor Paul Alivisatos between 1994 and 1999 brought him into the field of colloidal nanocrystals.
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China
Tuesday August 14th HT9
Toward Programmable Synthesis of Atom-precise and Multimetallic Clusters
1,2,3 3 1 1,3 Takane Imaoka , Hirokazu Kitazawa , Yuki Akanuma , Kimihisa Yamamoto
1 Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Japan 2 PRESTO-JST, 3 ERATO-JST Yamamoto Atom-Hybrid Project, Japan [email protected] The properties of nanoparticles are in general determined by their compositions and particle sizes. Recent progress of the nanoparticle synthesis allows their miniaturization approaching to 1 nm. However, we have already reached the theoretical limit of their utilization because the diameter is near the atomic level. In the nanoscale, the number of constituent atoms is thousands or more, and their physical properties gradually and continuously change according to the particle size (scalable regime) due to the statistical principle. On the other hand, in the subnanometer regime, the number of constituent atoms is only about several to several tens, and it shows quite different properties depending on the number of atoms (non-scalable regime). This fact means that the precision of the synthesis required in the subnanometer regime is at single-atom level. Here we show recent development in the chemical synthesis of atom-precise clusters[1-3] and multi-metallic clusters[4] from the multi-nuclear metal complexes of dendrimers or other topological molecules. They could be characterized by atom-resolution HAADF-STEM (high-angle annular-dark field scanning transmission electron microscopy) or ESI-TOF/mass, and exhibited unique behaviors in catalysis.
Figure 1: Template synthesis allowing atom-precise and multimetallic clusters.
[1] T. Imaoka, H. Kitazawa, W. Chun, S. Omura, K. Albrecht, K. Yamamoto, J. Am. Chem. Soc. 2013, 135, 13089-13095. [2] T. Imaoka, H. Kitazawa, W.-J. Chun, K. Yamamoto, Angew. Chem. Int. Ed. 2015, 54, 9810-9815. [3] T. Imaoka, Y. Akanuma, N. Haruta, S. Tsuchiya, K. Ishihara, T. Okayasu, W.-J. Chun, M. Takahashi, K. Yamamoto, Nature. Commun. 2017, 8, 688. [4] M. Takahashi, H. Koizumi, W.-J. Chun, M. Kori, T. Imaoka, K. Yamamoto, Sci. Adv. 2017, 3, e1700101.
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China
Tuesday August 14th HT10
I Cubic Aromaticity from Multicenter-Bonded [M ]8 (M=Zn, Mn) Cluster
1 2 1 2 Han-Shi Hu , Ping Cui , Jun Li , Bin Zhao
1 Department of Chemistry, Tsinghua University, Beijing 100084, China
2 Department of Chemistry, Nankai University, Tianjin 300071, China.
presenting author: [email protected]
Polynuclear transition-metal clusters [M8] with multicentered M-M bonds and +1 oxidation-state are completely unknown for M=Zn and Mn in chemistry. We report here the first polyzinc compounds with a I novel cubic [M 8] (M=Zn, Mn) cluster core, featured by unusual M(I) ions and short M-M bonds (2.271 Å I for Zn, 2.372 Å for Mn). The [Zn 8] bearing compounds possess surprisingly high stability in air and 1 I solutions. Quantum chemical studies reveal that the eight Zn 4s electrons in the [Zn 8] cluster fully occupy four bonding molecular orbitals and leave four antibonding ones entirely empty, leading to extensive electron delocalization over the cube and significant stabilization. Meanwhile, theoretical I investigations reveal that the 48 electrons in the [Mn 8] cube fully occupy half of the 3d-based and the lowest 4s-based bonding orbitals, with six electrons lying at the non-bonding 3d-orbitals. The bonding pattern of the cube represents a class of new aromatic systems that we refer to as cubic aromaticity, I I which follows a 6n+2 electron counting rule: n = 1 for [Zn 8] cube; and n = 0, 1 for [Mn 8] cube. Our finding extends the aromaticity concept to cubic metal systems for the first time, and enriches MI-MI bonding chemistry.
I Figure 1: The bonding pattern in [Mn 8] cube with dual cubic aromaticity from 4s-based 2 and 3dz -based molecular orbitals, respectively.
[1] P. Cui, H. S. Hu, B. Zhao, J. T. Miller, P. Cheng, J. Li, Nat. Commun. 2014, DOI: 10.1038/ncomms7331. [2] H. C. Hu, H. S. Hu, B. Zhao, P. Cui, P. Cheng, J. Li, Angew. Chem. Int. Ed. 2015, 54, 11681. [3] H. C. Hu, P. Cui, H. S. Hu, P. Cheng, J. Li, B. Zhao, Chem. Eur. J. 2018, 24, 3637.
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Tuesday August 14th INV10
How shape changes alter physico-chemical properties of nanoparticles Francesca Baletto1
1 Physics Department, King’s College London, UK
In this talk, I will revise the concept of metallic nanoparticles' design for target advanced applications starting from an accurate analysis of their geometrical features [1] and their fluxionality. Indeed, and atomistic understanding of thermal activated rearrangements and phase changes in metallic nanoparticles is one of the new challenges in cluster physics to address their feasibility in various applications. After a brief introduction on the numerical tools we have developed [2], I will address effective ways to include geometrical effects to estimating chemo-physical properties of nanosized metallic or bimetallic objects. As paradigmatic example, the prediction of optimal Pt-based nanocatalyts for oxygen reduction reaction will be discussed [3].
References
[1] C. DiPaola, et al., Nano Letters 16:2885 (2016); C. DiPaola, et al., Nanoscale 9:15658 (2017); C. DiPaola, et al., PCCP 13:7701(2011); JBA Davis, et al. JPCA 119:9703 (2015).
[2] K. Rossi et al. Sci. Rep. (2018) under revision; D. Schebarchov, et al. Nanoscale 10:2004 (2018); K. Rossi et al. EPJB 91:33; K. Rossi and F. Baletto PCCP 19:11057 (2017); K. Rossi et al. JPCM 29:145402 (2017); A. Gould et al. JPCL 7:4414 (2016); L. Pavan et al. JCP 143:184304 (2015).
[3] GG. Asara, et al., ACS Cat. 6:4388(2016); L.O. Paz-Borbon and F. Baletto, Inorganics 5:43.
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China
Tuesday August 14th HT11
Molecular beam study of the CO oxidation on regular arrays of Pd clusters
G. Sitja1, C.R. Henry1
1 Centre Interdisciplinaire de Nanoscience de Marseille/Aix-Marseille
University/ CNRS-UMR 7325, Marseille, France
Studies on supported model catalysts have shown that the catalytic activity of metal clusters depends on their size, their shape and their spatial distribution. A way to simultaneously control these parameters is to grow regular arrays of clusters on a template like a graphene or an h-BN monolayer or an ultrathin alumina film on a metal single crystal [1]. Hexagonal arrays of Pd and PdAu clusters in a size range 3-1000 atoms have been obtained by condensation of calibrated atomic beams on a alumina ultrathin film on Ni3Al (111) [2,3]. The size distribution of the clusters is not a single size as for size selected deposited clusters[4] but it is significantly sharper than for clusters grown on a normal substrate. Indeed the size dispersion (Δn/n) is 1/√n, then for n=150 atoms (diameter around 2nm) Δn/n= 8% and the diameter dispersion is 5%. The density of clusters is constant and large (6.5x1012 cm-2). With this method, the variation of the adsorption energy of a CO molecule has been measured as a function of cluster size, continuously from the non-scalable regime to the scalable regime [2]. More recently we have started the study of the CO oxidation on such arrays of Pd clusters [5]. Thanks to the regular spatial distribution of the clusters it is possible to correct the reaction rate from the effect of the reverse spillover of CO and then the reaction rate can be directly compared with measurements on Pd single crystals. In this talk we will present new results on the CO oxidation on clusters of different sizes. From transient measurements it becomes possible, for the first time, to accurately determine the Langmuir-Hinshelwood barrier as a function of cluster size. These values are then correlated with the adsorption energy of CO on clusters of the same size.
[1] C.R. Henry, Catal. Lett. 145(2015)731:2D-arrays of nanoparticles as model catalyst. [2] G. Sitja, S. Le Moal, M. Marsault, G. Hamm, F. Leroy, C.R. Henry, Nano. Lett. 13(2013)1977: Transition from molecule to solid state: Reactivity of supported metal clusters [3] M. Marsault, G. Sitja, C.R. Henry, PCCP 16(2014)26458: Regular arrays of Pd and PdAu clusters on ultrathin alumina films for reactivity studies [4] A.S. Crampton, M.D. Rötzer, C.J. Ridge, F.F. Schweinberger, U. Heiz, B. Yoon, U. Landman, Nature Commun. 7(2016)10389: Structure sensitivity in the nanoscale regime explored via catalyzed ethylene hydrogenation on supported platinum nanoclusters. [5] G. Sitja, C.R. Henry, J. Phys. Chem. C121(2017)10706: Molecular Beam study of the oxidation of carbon monoxide on a regular array of Palladium clusters on alumina
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Tuesday August 14th HT12
High Throughput and Rational Design of Transition Metal Cluster Catalyst Haoxiang Xu and Daojian Cheng* Beijing Key Laboratory of Energy Environmental Catalysis, Beijing University of Chemical Technology, Beijing 100029 *Email: [email protected] The development of transition metal nanocatalysts with high performance is a significant issue in energy chemical industry field. Based on the electron structure and reaction reactivity of catalysts investigated by density functional theory calculations, we construct a structurereactivity relation based on our proposed structure descriptors, by which nanocatalysts with high performance can be rationally designed. (1) We proposed a strategy to design more efficient Pd-based nanocatalysts combining the density functional theory (DFT) calculations and Sabatier analysis. The average valence electron of Pd-shell atoms is identified as the intrinsic factor for the activity and selectivity of the Pd-based nanocatalysts, which can be effectively tuned by the dopants. By introducing the dopants with suitable electronegativity, the valence electrons of Pd-shell atoms could be adjusted to the optimal range to enhance the activity and selectivity of the nanocluster simultaneously. With this strategy, Pd-W, Pd-Pb, Au-Pd-W, Au-Pd-Pb, Au-PdMo and Au-Pd-Ru are predicted as the potential candidates with the catalytic performance far exceeding the state-of-the-art experimental systems by scanning the periodic table [1]. (2) Using the prototype oxygen reduction, oxygen evolution and hydrogen evolution reactions (ORR, OER and HER) as benchmarks, we have performed an exhaustive search for highly active SACs, and further derived a universal design principle to evaluate the ORR/OER/HER activities of SACs on the functionalized graphene. Results indicate that the catalytic activity of SACs is highly correlated with the local environment of the catalytic center, including the coordination number and the electronegativity of the metal center and the nearest neighboring atoms, which is validated by available experimental data [2]. (3) We propose a simple, empirical model to capture the structure effect of the gold nanoparticles (Au NPs) on its adsorption strength and catalytic activity using CO oxidation as the probe. Based on the density functional calculations, a good linear relationship is identified initially between the geometry index (general coordination number and curvature angle of the surface Au atoms) of Au NP and the binding strength of CO and O2, which could further predict its catalytic activity by making use of Sabatier analysis. Besides, this simple and predictive model based on structure descriptors can be applies to Au NPs with various sizes (0.5 nm-3.5 nm) and shapes and provide experimentalists with an accurate estimate of the binding strength of the adsorbates on the NPs’ surface and catalytic activity by only knowing the geometry characteristics of NPs [3]. References: [1] Xu, H., Cheng, D. & Gao, Y. Design of High-Performance Pd-Based Alloy Nanocatalysts for
Direct Synthesis of H2O2. ACS Catal. 7 (2017) 2164-2170. [2] Xu, H., Cheng, D., Cao, D. & Zeng, X. A universal principle for a rational design of single-atom electrocatalysts. Nat. Catal. DOI:10.1038/s41929-018-0063-z (2018). [3] Xu, H., Cheng, D., Gao, Y. & Zeng, X. Efficient Predition of Catalytic Activities of Gold Nanoparticles Fig. 1 Schematic illustration for high throughput and with Geometry Descriptors. submitted. rational design of catalyst 19th ItInternational ti lS Symposium i on Small S llPtil Particles and dI Inorganic i Clusters August 12-17, 2018, Hangzhou China
Tuesday August 14th HT13
Enriching Silver Nanocrystals with a Second Noble Metal
Dong Qin School of Materials Science and Engineering
771 Ferst Drive, Atlanta, GA 30332
[email protected] In this talk, I will use Ag nanocubes as an example to demonstrate the fabrication of Ag@M and Ag@Ag-M (M=Au, Pd, or Pt) nanocubes with a core-frame or core-shell structure by controlling the deposition of M atoms. A typical synthesis involves the titration of Mn+ (a precursor to M) ions into an aqueous solution containing Ag nanocubes, ascorbic acid, and poly(vinylpyrrolidone) under ambient conditions. In one approach, aqueous sodium hydroxide is introduced to increase the initial pH of the reaction solution. At pH = 11.9, ascorbic acid is dominated by ascorbate monoanion, a much stronger reductant, to suppress the galvanic replacement between Mn+ and Ag. In this case, the M atoms derived from the reduction by ascorbate monoanion are sequentially deposited on the edges, corners, and side faces to generate Ag@M core-frame and then core-shell nanocubes. The other approach involves the use of ascorbic acid as a relatively weak reductant while Mn+ is co-titrated with Ag+ ions in the absence of sodium hydroxide. At pH = 3.2, when the molar ratio of Ag+ to Mn+ is sufficiently high, the added Ag+ ions can effectively push the galvanic reaction backward and thus inhibit it. As a result, co-reduction of the two precursors by ascorbic acid produces Ag and M atoms for the generation of Ag@Ag-M core-frame nanocubes with increasingly thicker ridges. The Ag@Ag-Pd core-frame nanocubes can serve as a dual catalyst to promote the stepwise reduction of nitroaromatics to aminoaromatics and then oxidation to azo compounds. The consecutive reactions can be monitored using surface- enhanced Raman scattering (SERS). The Ag@Au core-shell nanocubes with Au shells of three or six atomic layers exhibit plasmonic peaks almost identical to those of the Ag nanocubes while the chemical stability and SERS activity are substantially augmented. For both types of bimetallic nanocubes, the Ag cores can be selectively removed to generate nanoframes and nanoboxes.
[1] Y. Wu, X. Sun, Y. Yang, J. Li, Y. Zhang, D. Qin, Acc. Chem. Res. 2017, 50, 1774.
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Tuesday August 14th M1
Memorial Lecture for
Albert Welford Castleman, JR
Pioneer of Cluster Science Opening New Research Directions for the Future
Vlasta Bonačić-Koutecký 1,2
1 Center of excellence for science and technology—integration of Mediterranean region (STIM) at Interdisciplinary Center for Advanced Sciences and Technology (ICAST) at University of Split, Poljička cesta 35, 21000 Split (Croatia)
2 Chemistry Department, Humboldt University of Berlin, Brook-Taylor-Strasse 2, 12489 Berlin (Germany)
Abstract
Contributions including water cages; solvation dynamics; atmospheric cluster reactions; metal oxide clusters as novel catalysts; aluminium clusters as superatoms; metcars and ultrafast-Coulomb explosion forming concepts opening new research directions. Outlook of cluster science motivated by A. W. Castleman's achievements will be given.
Word cloud compiled by Amy Trost (NIST research librarian) from Web of Science titles, abstracts, and keywords.
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Tuesday August 14th M2: Memorial Lecture for Koji Kaya
Superatom Periodic Table of Caged Nanoclusters
Atsushi Nakajima1,2 1 Department of Chemistry, Faculty of Science and Technology, Keio University, Japan 2 Keio Institute of Pure and Applied Sciences (KiPAS), Keio University, Japan [email protected] Since well-established function miniaturization of silicon (Si) devices with photolithography has almost reached its technological limit, it is urgent to explore new Si based low-dimensional functional nanomaterials with bottom-up technologies utilizing physicochemical synthetic methods in the gas and liquid phases. However, a “zero dimensional (0D)” caged Si compound, including Si60, has not been identified. The formation of 0D Si cage was experimentally suggested by metal-encapsulation inside a Si cage, M@Sin, by mass spectrometry for mixed vapors of metal and Si in 1987 [1]. Although some other experimental and theoretical researches have been reported extensively, the caged Si compounds have never been realized as a new form nanomaterial of 0D Si cage. On the other hand, a physical concept of “superatoms” has been introduced, where new atomic-like orbitals (super atomic orbital; SAO) are constructed by valence electrons delocalized over nanoclusters comprised of several to hundreds of atoms. Since alloying of nanoclusters additionally gives a designer parameter to control their electronic structures in addition to a cluster size, the metal encapsulation inside a Si cage can be regarded as binary cage superatoms (BCSs). We have found a periodic family of M@Si16 BCSs based on mass spectrometry, where - (0) + halogen-like (Sc@Si16 ), rare gas-like (Ti@Si16 ), and alkali-like(V@Si16 )SAs have been demonstrated by the group -3, -4, and -5 atom encapsulations, respectively [2]. The unique compositions of these BCSs originates from the simultaneous satisfaction of geometric and electronic shell-closings in terms of cage geometry and valence electron filling, where they complete their SAO closure for the same number of 68 valence electrons, in which 16 Si atoms and a central M atom provide 64 and 4 electrons, respectively, including a charge state. Toward functional materials in the solid state, we have developed an intensive, size-selected nanocluster source based on high-power impulse magnetron sputtering [3,4] coupled with a mass spectrometer and a soft-landing apparatus. With scanning probe microscopy and photoemission spectroscopy, the structure of surface-immobilized BCSs has been elucidated [5,6]. Beyond the surface immobilization of the M@Si16 BCSs, furthermore, we have developed a large-scale synthesis method for M@Si16 (M = Ti and Ta) by a direct liquid embedded trapping (DiLET) method [7]. The spectroscopic results reveal that the structures of isolated M@Si16 BCSs are the metal-encapsulating tetrahedral Si-cage (METS) [7,8].
[1] S. M. Beck, J. Chem. Phys. 1989, 90, 6306. Figure 1:M@Si16BCS [2] K. Koyasu, A. Nakajima, et al. J. Am. Chem. Soc. 2005, 127, 4998. [3] H. Tsunoyama, A. Nakajima, et al. Chem. Lett. 2013, 42 , 857. [4] C. H. Zhang, A. Nakajima, et al. J. Phys. Chem. A 2013, 117, 10211. [5] M. Nakaya, A. Nakajima, et al. Nanoscale 2014, 6, 14702. [6] M. Shibuta, A. Nakajima, et al. J. Am. Chem. Soc. 2015, 137, 14015. [7] H. Tsunoyama, A. Nakajima, et al. J. Phys. Chem. C 2017, 121, 20507. [8] H. Tsunoyama, M. Shibuta, M. Nakaya, T. Eguchi, A. Nakajima, Accounts of Chemical Research 2018 in press.
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China
Tuesday August 14th HT14
Monolayer-Protected Clusters: Structurally Precise Building Blocks for Spintronic Applications
Kenneth L. Knappenberger, Jr.
Department of Chemistry, The Pennsylvania State University, USA
Monolayer-protected clusters (MPCs) are an emerging class of inorganic nanostructures that can be synthesized and isolated with atomic precision. Control over MPC composition results, in part, from electron filling of Superatom orbitals, yielding colloidal metal nanoparticles of specific magic sizes. These synthetic advances overcome many limitations of inherently heterogeneous colloidal metal nanoparticle syntheses. Recently, post-synthetic electrochemical methods for manipulating the oxidation state of stable MPCs have been demonstrated. Here, femtosecond time-resolved and magneto-optical spectroscopy studies of a family of MPCs in the 1-2 nm size range will be presented. These results show that the optical, electronic and magnetic properties of MPCs are extremely sensitive to the electronic configuration of
Superatom orbitals. For example, the magnetic properties of Au25(SR)18, where SR represents an alkanethiol, can be switched reversibly by oxidative opening of the eight-electron Superatom P orbital. Collective interactions between assembled MPCs also exhibit spin-dependent magnetic phenomena not present in the isolated building blocks. Magnetic Circular Dichroism and time- dependent spectroscopy on dimerized 20-atom MPCs reveal inter-particle spin- dependent dynamics not observed for the monomer. Importantly, these results indicate that the magnetic properties of gold MPCs result from the electronic configuration of metal-based Superatom orbitals.
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China
Tuesday August 14th HT15 Hydride-doped Gold Superatoms: Synthesis, Structure and Transformation
1 1 1 1,2 Shinjiro Takano , Haru Hirai , Satoru Muramatsu , Tatsuya Tsukuda
1 Graduate School of Science, The University of Tokyo, Japan
2 ESICB, Kyoto University, Japan
The interaction of hydrogen with gold clusters has been of great interest since it significantly affects the physicochemical properties. For example, we reported small nonplasmonic Au clusters exhibit localized surface plasmon resonance in the presence of NaBH4 due to electron donation from the adsorbed H atoms [1,2]. These observations suggest an analogy between Au and H as has been demonstrated experimentally and theoretically on bare Au clusters [3,4]. Although a recent theoretical study proposed that an H atom behaves as an Au atom in the thiolate-protected Au cluster and contributes its 1s electron to the superatomic electron count [5], less is known about the interaction between H and Au clusters because hydrogen doping has not been experimentally observed in ligand-protected Au clusters. We herein report the first observation of doping of a hydride (H–) to a coordinatively 3+ unsaturated site of [Au9(PPh3)8] by mass spectrometry and NMR spectroscopy. Density functional theory calculations demonstrated 3+ that oblate-shaped (Au9) superatomic core of 3+ [Au9(PPh3)8] was converted to a nearly 2+ spherical (Au9H) superatom with a closed electronic shell (8e). We also demonstrated 2+ that this superatom (Au9H) can be 3+ transformed into the well-known Au11 by the sequential addition of AuCl units. This growth process will provide a new atomically precise synthesis of Au clusters via bottom-up Scheme 1. Formation and reactivity of hydride- approach. doped Au superatom
[1] Ishida, R.; Yamazoe, S.; Koyasu, K.; Tsukuda, T. Nanoscale 2016, 8, 2544. [2] Ishida, R.; Hayashi, S.; Yamazoe, S.; Kato, K.; Tsukuda, T. J. Phys. Chem. Lett. 2017, 8, 2368. [3] Buckart, S.; Ganteför, G.; Kim, Y. D.; Jena, P. J. Am. Chem. Soc. 2003, 125, 14205. [4] Mondal, K.; Agrawal, S.; Manna, D.; Banerjee, A.; Ghanty, T. K. J. Phys. Chem. C 2016, 120, 18588. [5] Hu, G.; Tang, Q.; Lee, D.; Wu, Z.; Jiang, D.-e. Chem. Mater. 2017, 29, 4840.
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Tuesday August 14th INV11
Highly charged ions from intense laser-cluster interactions revisited
Thomas.Fennel1,2
1 University of Rostock, Albert-Einstein-Straße 23, 18059 Rostock, Germany
2 Max-Born-Institute, Max-Born-Straße 2A, 12489 Berlin, Germany
[email protected] / [email protected]
The observation of extremely highly charged ions from intense laser cluster interactions [1] was one (if not the) key driver of the quest for a deeper understanding of laser-nanoplasmas [2,3]. Already in early stages of strong-field cluster physics, the importance of avalanching and local field enhancement for explaining high atomic ionization in the nanoplasma has been realized [4,5]. The severe impact of the correlation-driven processes including relocalization, recombination, and autoionization in the expanding cluster nanoplasma has, however, been identified only much later [6,7,8]. In this talk I will discuss two very recent experimental studies [9,10] that provided unprecedented insights into correlation-driven electrons dynamics in IR excited rare-gas clusters and will discuss our attempts to unravel the underlying many- particle physics via atomistic simulations.
References:
[1] E. M. Snyder et al., Phys. Rev. Lett. 77, 3347 (1996). [2] U. Saalmann et al., J. Phys. B 39, R39 (2006). [3] T. Fennel et al., Rev. Mod. Phys. 82, 1793 (2010). [4] T. Ditmire et al., Nature 386, 54 (1997). [5] L. Köller et al., Phys. Rev. Lett. 82, 3783 (1999) [6] T. Fennel et al., Phys. Rev. Lett. 99, 233401 (2007). [7] T. Döppner et al., , Phys. Rev. Lett. 105, 053401 (2010). [8] B. Schütte et al., Nat. Commun. 6, 8596 (2015). [9] D. Komar et al., Phys. Rev. Lett. 120, 133207 (2018). [10] B. Schütte et al., submitted 2018
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China
Tuesday August 14th HT16
Single-center iron(VII) trioxide clusters: iron in the remarkable +7 oxidation state
R. Lindblad,1,2 V. Zamudio-Bayer,2,3 C. Bülow,2,4 M. Timm,2,4 A. Ławicki,2 K. Hirsch,2 A. Terasaki,5 B. von Issendorff,3 J. T. Lau2,3
1 Department of Physics, Lund University, Sweden
2 Institut für Methoden und Instrumentierung der Forschung mit Synchrotronstrahlung,
Helmholtz-Zentrum Berlin für Materialien und Energie, Germany
3 Physikalisches Institut, Universität Freiburg, Germany
4 Institut für Optik und Atomare Physik, Technische Universität Berlin, Germany
5 Department of Chemistry, Kyushu University, Japan
We present conclusive experimental evidence for iron in the remarkable formal oxidation state of +7, the highest that has been demonstrated for iron in any compound, so far. Iron, after manganese, is only the second 3d transition element for which an oxidation state as high as +7 is found. This is even more surprising as the tendency to form high oxidation states is generally thought to peak at manganese and to decrease along the 3d transition series for elements with more than half-filled 3d shells.
+ The smallest molecular iron oxides, FeOn with n = 1 – 4, containing only a single iron center, have been studied by x-ray absorption and x-ray magnetic circular dichroism spectroscopy in a cryogenic ion trap. This allows us to separately probe transitions into metal and oxygen centered orbitals, to detect orbital and spin magnetizations, and to determine chemical species.
Analysis of the line shape and excitation energy shifts at the oxygen K edge and iron L2,3 edge spectra give independent evidence of the unusual +7 oxidation state of iron, the highest that has been demonstrated so far in the ground state of any iron compound, in gaseous low-spin + [Fe(VII)O3] ions. This highest oxidation state of iron goes along with electron delocalization into strongly hybridized molecular orbitals, leading to reduced local 3d character at the iron site, and to spin pairing in molecular orbitals, with a resulting low-spin state. This causes reduced local 3d electron density in the vicinity of the 2p core hole and leads to blue shifts of the iron 2p – 3d excitation energy of 0.7 – 0.9 eV per formal oxidation state because of reduced core-hole screening.
[1] R. Lindblad, V. Zamudio-Bayer, C. Bülow, M. Timm, A. Ławicki, K. Hirsch, A. Terasaki, B. von Issendorff, J. T. Lau, submitted for publication
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China
Tuesday August 14th HT17
Exploring the surface energy and surface stability of Ag nanocrystals: an in-situ TEM method
L.B. He1,2, L. Zhang1, Y.F. Yang1
1 SEU-FEI Nano-Pico Center, Key Lab of MEMS of Ministry of Education, Southeast University, Nanjing 210096, P. R. China
2 Center for Advanced Materials and Manufacture, Joint Research Institute of Southeast University and Monash University, Suzhou 215123, P. R. China
In the previous studies, the surface energy and surface stability of Ag NCs were under fierce debate because the measurable values of the surface energy were very inconsistent (from 1 to 7.2 J/m2), and the indices of the observed thermally stable surfaces were apparently in conflict [1]. These lead to wrong understandings of the shape evolution and wetting behaviors of Ag NCs at elevated temperatures [2]. To clarify this issue, a transmission electron microscope is used to investigate these problems in situ with elaborately designed carbon-shell-capsulated Ag NCs [3,4]. It is demonstrated that the {111} surfaces are still thermally stable at elevated temperatures, and the victory of the formation of {110} over {111} surfaces on the Ag NCs during sublimation is due to the special crystal geometry. Ag NCs are found to behave as quasi- liquids during sublimation, and the cubic NCs represent a featured shape evolution, which is codetermined by both the wetting equilibrium at the A-C interface and the relaxation of the system surface energy. Using sublimation kinetics, the mean surface energy of Ag NCs is quantitatively estimated. Also, the wetting behaviors of Ag NCs to carbon materials (such as graphene and graphite-like films) are explored and discussed.
Figure 1: Shape evolution of a Ag NC at 1073 K. (a-f) The first stage of the shape evolution. (g-o) The second stage of the shape evolution. The insets in (g) show that the cubic Ag NC has a monocrystalline structure and obtuse vertices.
[1] L. B. He, L. Zhang, L. P. Tang, J. Sun, Q. B. Zhang, and L. T. Sun, Materials Today Nano 1, 8 (2018). [2] Y. Ding, F. Fan, Z. Tian, and Z. L. Wang, Small 5, 2812 (2009). [3] L.-B. He, L. Zhang, X.-D. Tan, et al. Small 13, 1700743 (2017). [4] R. Lian, H. Yu, L. He, L. Zhang, Y. Zhou, X. Bu, T. Xu, and L. Sun, Carbon 101, 368 (2016).
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China
Tuesday August 14th HT18
Photoelectron Spectroscopy and Theoretical Investigate of Transition Metal-doped Semiconductor Clusters
Wei-Jun Zheng
Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
E-mail: [email protected]
We investigated the structures and electronic properties of a series of transition metal- doped semiconductor clusters using anion photoelectron spectroscopy and density functional theory calculations. A number of clusters with high symmetric structures have been identified, − − − − − − such as V3Si12 , NbSi12 , AuGe12 , Nb2Si3 , Nb2Si6 , and Nb2Si12 . Our results also indicate that the structural evolutions of metal-doped silicon clusters and the critical sizes for the formation of endohedral structures are different not only for the metals from different groups but also for different metals in the same group in the periodic table. The structural information obtained in our work might be useful for the development of cluster-assembled materials and fullerene-like semiconductor materials.
[1] Sheng-Jie Lu, Xi-Ling Xu, Guo-Jin Cao, Hong-Guang Xu, and Wei-Jun Zheng, J. Phys. Chem. C 122, 2391 (2018). [2] Xiao-Jiao Deng, Xiang-Yu Kong, Xiaoqing Liang, Bin Yang, Hong-Guang Xu, Xi-Ling Xu, Gang Feng, Wei-Jun Zheng, J. Chem. Phys. 147, 234310 (2017). [3] Sheng-Jie Lu, Hong-Guang Xu, Xi-Ling Xu, and Wei-Jun Zheng, J. Phys. Chem. C 121, 11851 (2017). [4] Xiao-Qing Liang, Xiao-Jiao Deng, Sheng-Jie Lu, Xiao-Ming Huang, Ji-Jun Zhao, Hong-Guang Xu, Wei-Jun Zheng, and Xiao Cheng Zeng, J. Phys. Chem. C 121, 7037 (2017). [5] Sheng-Jie Lu, Guo-Jin Cao, Xi-Ling Xu, Hong-Guang Xu and Wei-Jun Zheng, Nanoscale 8, 19769 (2016). [6] Sheng-Jie Lu, Lian-Rui Hu, Xi-Ling Xu, Hong-Guang Xu, Hui Chen, and Wei-Jun Zheng, Phys. Chem. Chem. Phys. 18, 20321 (2016). [7] Xiaoming Huang, Sheng-Jie Lu, Xiaoqing Liang, Yan Su, Linwei Sai, Zeng-Guang Zhang, Jijun Zhao, Hong-Guang Xu, Weijun Zheng, J. Phys. Chem. C 119, 10987 (2015).
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Wednesday, August 15th 2018
Session IX (Session chair: Akira Terasaki) 8:00 – 8:40 The Methane Challenge: C-H Bond Activation and C-C Coupling Helmut Schwarz 8:40 – 9:20 Synthesis, Structure and Reactivity of Coinage Metal Nanoclusters Richard O’Hair 9:20 – 9:40 Catalytic Oxidation of Methane Mediated by Free Gold Clusters: Gas-Phase Kinetics, IR- Spectroscopy, and Ab Initio Theory Thorsten Bernhardt 9:40 – 10:00 Methane Activation and Transformation by Atomic Clusters Sheng-Gui He 10:00 – 10:30 Break Session X (Session chair: Wolfgang Harbich) 10:30 – 11:10 Organic Synthesis of Endohedral Fullerenes Encapsulating Small Molecules Yasujiro Murata
11:10 – 11:30 Single Photon Thermal Ionization of C60 Klavs Hansen
11:30 – 11:50 Structure and Stability of Thorium Dioxide Nanoclusters (ThnO2n with n =1-8): A First- Principle Study Ping Yang 11:50 – 12:10 Photoelectron Spectroscopy of Polyanionic Metal Clusters Lutz Scheikhard 12:10 – 13:30 Lunch
13:30 – 18:00 Excursion
18:30 – 21:30 Conference Banquet
Wednesday August 15th INV12
The Methane Challenge: CH bond Activation and CC Coupling
Helmut SCHWARZ, Caiyun Geng, Jilai Li, Xiaoyan Sun, Lei Yue, and Shaodong Zhou
Institut für Chemie, Technische Universität Berlin, 10623 Berlin, Germany
In this lecture we will discuss a story of one molecule (methane), a few metal-oxide cationic clusters (MOCCs), dopants, metal-carbide cations, oriented-electric fields (OEFs), and a dizzying mechanistic landscape of methane activation! One mechanism is hydrogen atom transfer (HAT), which occurs whenever the MOCC possesses a localized oxyl radical (M−O•). •+ Whenever the radical is delocalized e.g., in [MgO]n the HAT barrier increases due to the •+ penalty of radical localization. Adding a dopant (Ga2O3) to [MgO]2 localizes the radical and
•+ HAT transpires. Whenever the radical is located on the metal centers as in [Al2O2] the mechanism crosses-over to proton-coupled electron transfer (PCET), wherein the positive Al center acts as a Lewis acid that coordinates the methane molecule, while one of the bridging oxygen atoms abstracts a proton, and the negatively charged CH3 moiety relocates to the metal fragment. We provide a diagnostic plot of barriers vs. reactants-distortion energies, which •+ allows the chemist to distinguish HAT from PCET. Thus, doping of [MgO]2 by Al2O3 enables HAT and PCET to compete. Similarly, [ZnO]•+ activates methane by PCET generating
•+ many products. Adding a CH3CN ligand to form [(CH3CN)ZnO] leads to a single HAT + product. The CH3CN dipole acts as an OEF that switches off PCET. [MC] cations (M = Au,
Cu) act by different mechanisms, dictated by the M+−C bond covalence. For example, Cu+, which bonds the carbon atom mostly electrostatically, performs coupling of C to methane to yield ethylene, in a single almost barrier-free step, with an unprecedented atomic choreography catalyzed by the OEF of Cu+.
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China
Wednesday August 15th INV13
Synthesis, structure and reactivity of coinage metal nanoclusters
A. Zavras 1, J. Li 1, H. Ma 1, G. N. Khairallah 1, P. S. Donnelly 1, R. J. Mulder 2, M. Krstić 3, M. Girod 4, L. MacAleese 4, S. Daly 4, R. Antoine 4, A. J. Canty 5, V. Bonačić-Koutecký 3, P. Dugourd 4, R. A. J. O’Hair 1
1 School of Chemistry, University of Melbourne, Australia.
2 CSIRO Manufacturing, Australia.
3 Interdisciplinary Center for Advanced Sciences and Technology, University of Split, Croatia
4 Institut Lumière Matière, Université Lyon 1-CNRS, France
5 School of Natural Sciences, University of Tasmania, Australia.
Coinage metal nanoclusters (CMNs) continue to attract attention as models for nanoparticles, for their structure and bonding arrangements, spectroscopic properties and roles in catalysis. We have been using an approach the blends electrospray ionization mass spectrometry to direct the bulk synthesis of CMNs, X-ray crystallography, neutron diffraction and NMR spectroscopy for structural characterization, and multistage mass spectrometry (MSn) experiments in conjunction with DFT calculations to examine the chemistry of CMNs.
In this talk I will highlight our work on coinage metal:
(1) hydride nanoclusters and their reactions that result in the release of hydrogen as models for hydrogen storage [1,2] and transformation of organic substrates [3]; (2) alkyl and aryl nanoclusters where differences and similarities in their unimolecular fragmentation chemistry are examined [4]; (3) alkynyl nanoclusters where their C-C bond coupling reactions are explored [5].
[1] A. Zavras et al., Nature Communications, 2016, 7, 11746 [2] J. Li et al., Chem. Eur. J., 2018, 24, 2070 [3] H. Ma et al., Dalton Trans., 2017, 46, 14995 [4] S. Weske, et al., Chem. Comm., 2018, 54, 5086 [5] S. Daly et al., J. Phys. Chem. C, 2017, 121, 10719
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Wednesday August 15th HT19
Catalytic Oxidation of Methane Mediated by Free Gold Clusters: Gas-Phase Kinetics, IR-Spectroscopy, and Ab Initio Theory
Thorsten M. Bernhardt,1 Sandra M. Lang,1 Valeriy Chernyy,2 Joost M. Bakker,3 Robert N. Barnett,4 Uzi Landman4 1Institute of Surface Chemistry and Catalysis, University of Ulm, 89069 Ulm, Germany. 2Institute for Molecules and Materials, Radboud University, 6525 AJ Nijmegen, The Netherlands. 3Institute for Molecules and Materials, FELIX Laboratory, 6525 ED Nijmegen, The Netherlands. 4School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430, USA. [email protected] Methane represents the major constituent of natural gas. It is primarily used only as a source of energy by means of combustion, but could also serve as an abundant hydrocarbon feedstock for high quality chemicals. One of the major challenges in catalysis research nowadays is therefore the development of materials that selectively cleave one of the four C-H-bonds of methane and make it thus amenable for further chemical conversion to more valuable compounds. We previously demonstrated that small gold clusters are able to selectively activate methane employing gas phase reaction kinetics experiments in an octopole ion trap [1-6]. These + experimental studies revealed the particular catalytic properties of the gold dimer Au2 to activate methane and to convert two methane molecules to ethylene at thermal reaction conditions [1] or even to produce formaldehyde in reaction with molecular oxygen [4]. These experiments have now been complemented by infrared multi photon dissociation spectroscopy employing the free electron laser FELICE at the University of Nijmegen [7]. These investigations demonstrate that the interaction of methane with small gold cluster cations leads to + selective C-H-bond dissociation and the formation of hydrido-methyl complexes H-Aux -CH3. Ab initio calculations reveal that the distinctive selectivity offered by these gold clusters originates from a fine interplay between the closed-shell nature of the gold d-bands and relativistic effects that make them available for binding with methane. Such fine balance in fundamental interactions could prove a ‘tunable’ feature in rational catalyst design.
Figure 1: IR spectroscopy in conjunction with ab initio calculations demonstrate that small gold clusters can mediate the selective dissociation of one of the four CH bonds of methane.
[1] S.M. Lang, T.M. Bernhardt, R.N. Barnett, U. Landman, Angew. Chem. Int. Ed. 49 (2010) 980. [2] S.M. Lang, T.M. Bernhardt, R.N. Barnett, U. Landman, Chem. Phys. Chem. 11 (2010) 1570. [3] S.M. Lang, T.M. Bernhardt, Eur. J. Phys. D 52 (2009) 139. [4] S.M. Lang, T.M. Bernhardt, R.N. Barnett, U. Landman, J. Phys. Chem. C 115 (2011) 6788. [5] S.M. Lang, A. Frank, T.M. Bernhardt, Cat. Sci. Technol. 3 (2013) 2926. [6] S.M. Lang, A. Frank, T.M. Bernhardt, Int. J. Mass Spectrom. 354-355 (2013) 365. [7] S.M. Lang, T.M. Bernhardt, V. Chernyy, J.M. Bakker, R.N. Barnett, U. Landman, Angew. Chem. Int. Ed. 56 (2017) 13406.
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China
Wednesday August 15th HT20
Methane activation and transformation by atomic clusters
Yan-Xia Zhao and Sheng-Gui He
Institute of Chemistry, Chinese Academy of Sciences, P. R. China
Selective activation and direct transformation of methane, the most stable alkane molecule, into value-added products is very challenging. To find mechanisms of methane activation and transformation under ambient conditions, we have studied the gas phase reactions between methane and a series of atomic clusters under thermal collision conditions with mass spectrometry, photo-electron spectroscopy, and quantum chemistry calculations. Recent research progresses have been made on the reaction systems of noble metal doped hetero- nuclear metal oxide clusters [1-4] and metal carbide clusters [5-6]. The Lewis acid-base pairs, metal centers in low spin states can activate methane effectively. Coupling of CH4 with other stable molecules including CO2 and H2O mediated with the cluster ions has also been identified.
+ Figure 1: Time-of-flight mass spectra for the reactions of mass-selected RhAl3O4 (a) with CH4
(b and c) and CD4 (d) for 1.5 ms [4].
[1] Zhao, Y.-X.; Li, Z.-Y.; Yuan, Z.; Li, X.-N.; He, S.-G. Angew. Chem. Int. Ed. 2014, 53, 9482. [2] Zhao, Y.-X.; Li, X.-N.; Yuan, Z.; Liu, Q.-Y.; Shi, Q.; He, S.-G. Chem. Sci. 2016, 7, 4730. [3] Li, Z.-Y.; Li, H.-F.; Zhao, Y.-X.; He, S.-G. J. Am. Chem. Soc. 2016, 138, 9437. [4] Li Y.-K.; Yuan Z.; Zhao Y.-X.; Zhao C.; Liu Q.-Y.; Chen H.; He S.-G. J. Am. Chem. Soc. 2016, 138, 12854. [5] Liu, Q.-Y.; Ma, J.-B.; Li, Z.-Y.; Zhao, C.; Ning, C.-G.; Chen, H.; He, S.-G. Angew. Chem. Int. Ed. 2016, 55, 5760. [6] Li H.-F.; Jiang L.-X.; Zhao Y.-X.; Liu Q.-Y.; Zhang T.; He S.-G. Angew. Chem. Int. Ed. 2018, 57, 2662.
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China
Wednesday August 15th INV14
Organic Synthesis of Endohedral Fullerenes Encapsulating Small Molecules
Yasujiro Murata Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan [email protected] Endohedral fullerenes represent caged-clusters of carbon encapsulating metal ions, metal clusters, atoms, and molecules. Although their syntheses mainly rely on physical methods under harsh conditions, organic synthesis has been attracting interests to realize molecule- encapsulating fullerenes owing to high selectivity of fullerene cages and high yields of desired products.[1] The “molecular surgery” was able to be applied to fullerene C70 in spite of difficulties in characterization of products due to the low symmetry compared with C60. Importantly, reflecting the larger inner space than C60, two small molecules were introduced inside open-cage C70 derivatives to afford the corresponding doubly-encapsulating C70 such as (H2O)2@C70[2] and (H2O-HF)@C70[3] in addition to mono-encapsulating H2O@C70 and HF@C70. On the other hand, applying combination of the molecular surgery and ion implantation, doubly-encapsulating (H2-N)@C70[4] was able to be generated, in which the atomic nitrogen interacts with the hydrogen molecule, without forming covalent bonds. Furthermore, we also demonstrated the synthesis of azafullerene H2O@C59N encapsulating a water molecule.[5]
Figure 1: Structures of endohedral fullerenes encapsulation small molecules.
[1] A Single Molecule of Water Encapsulated in Fullerene C60, Kurotobi, K.; Murata, Y. Science 2011, 333, 613-616. [2] Synthesis of a Distinct Water Dimer inside Fullerene C70, Zhang, R.; Murata, M.; Aharen, T.; Wakamiya, A.; Shimoaka, T.; Hasegawa, T.; Murata, Y. Nat. Chem. 2016, 8, 435-441. [3] Isolation of the Simplest Hydrated Acid, Zhang, R.; Murata, M.; Wakamiya, A.; Shimoaka, T.; Hasegawa, T.; Murata, Y. Sci. Adv. 2017, 3, e1602833 (6 pages). [4] Fullerene C70 as a "Nano-flask" to Reveal Chemical Reactivity of a Nitrogen AtomMorinaka, Y.; Zhang, R.; Sato, S.; Nikawa, H.; Kato, T.; Furukawa, K.; Yamada, M.; Maeda, Y.; Murata, M.; Wakamiya, A.; Nagase, S.; Akasaka, T.; Murata, Y. Angew. Chem. Int. Ed. 2017, 56, 6488-6491. + [5] Facile Access to Azafullerenyl Cation C59N and Specific Interaction with Entrapped Molecules, Hashikawa, Y.; Murata, Y. J. Am. Chem. Soc. 2017, 139, 18468-18471.
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Wednesday August 15th HT21
Single Photon Thermal Ionization of C60
K. Hansen1, R. Richter2, M. Alagia3, S. Stranges3,4, L. Schio3, P. Salén5, V. Yatsyna6, R. Feifel6, and V. Zhaunerchyk6 1Center for Joint Quantum Studies and Department of Physics, Tianjin University, Tianjin, P.R. China 2Elettra—Sincrotrone Trieste, Area Science Park, 34149 Basovizza, Trieste, Italy 3IOM-CNR Tasc, SS-14, Km 163.5 Area Science Park, Basovizza, Trieste, Italy 4Dipartimento di Chimica e Tecnologie del Farmaco, Universitá Sapienza, Rome, Italy 5Department of Physics, Stockholm University, Stockholm, Sweden 6Department of Physics, University of Gothenburg, Gothenburg, Sweden [email protected]
We have shown that C60 can be ionized in an indirect, quasi-thermal boil-off process after absorption of a single photon [1]. The process involves a large number of incoherently excited valence electrons and yields electron spectra with a Boltzmann distribution with temperatures exceeding 104 K.
Electron spectra were measured at the gas phase beamline at the synchrotron ring Elettra with a velocity map imaging (VMI) detector and in coincidence with the produced ion for a range of photon energies, from 13.5 to 65 eV. The thermal electron effect was deduced from the persistent low electron kinetic energy signal of an exponential, Boltzmann-type form, and the complete lack of angular structure in the low energy electrons for photon energies above ca. 20 eV. Conventional thermionic emission would give the same signal but is ruled out by the very large temperatures seen in the electron spectra. The coincidence technique permits to + trace the appearance of fragmentation of the produced C60 ions and shows an energy dependence consistent with known appearance energies of the fullerene fragments.
The findings expand previous observations on multiphoton hot electron ionization of fullerenes, PAH molecules and metal clusters. The single photon nature of the process provides evidence that the creation of a highly and incoherently excited electronic subsystem does not depend on sequential absorption of a large number of subthreshold photons, but can be induced by absorption of a single high energy photon. This will have implications for the understanding of both short time electron dynamics and electron-photon interactions in a molecular settings. [1] Klavs Hansen et al., Phys. Rev. Lett. 118 (2017) 103001 [2] K. Hansen, Phys. Chem. Chem. Phys. 19 (2017), 19699
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Wednesday August 15th HT22
Structure and stability of thorium dioxide nanoclusters (ThnO2n with n=1-8): a first-principle study
Néstor F. Aguirre, Julie Jung, Ping Yang*
Theoretical Division, Los Alamos National Laboratory Los Alamos, NM, 87545, the United States Email: [email protected]
Nanomaterial fuels have emerged as a promising candidate for a new generation of nuclear energy applications, with improved efficiency and safety of the fuel cycle. As the bulk form of nuclear fuels is known to recrystallize into nano-sized grains under high irradiation conditions, nanomaterial fuels could thus enhance stability against restructuring at medium-to-high burn-ups. Meanwhile, thorium dioxide (ThO2) is also emerging as a more efficient and safer alternative to uranium dioxide (UO2). In addition of being more abundant and easily accessible than uranium, thorium raises less concerns in terms of safety, storage and proliferation. Therefore, ThO2-based nanomaterials are expected to be a great candidate to outperform the existing UO2-based fuel. Yet, very little is known about the geometry, energetics and electronic structure of ThO2 nanomaterials. In this talk, the very first systematic study of stoichiometric thorium dioxide nanoclusters
(ThnO2n with n=1-8) will be presented. We will report an ensemble of structural sampling in conformational space for each size of cluster based on first-principle theory, density functional theory, combined with a novel chemically-driven global search algorithm. Based on the correlations between structures and energies, we come to understand the structural and chemical features that stabilize the clusters.
LA-UR-18-24441
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Wednesday August 15th HT23
Photoelectron Spectroscopy of Polyanionic Metal Clusters
M. Müller1,2, F. Martinez2, N. Iwe2, K. Raspe2, S. Bandelow1, G. Marx1, J. Tiggesbäumker2, L. Schweikhard1, K.-H. Meiwes-Broer2 1 Inst. of Physics, Univ. of Greifswald, Felix-Hausdorff-Str. 6, D-17489 Greifswald, Germany 2 Inst. of Physics, Univ. of Rostock, Albert-Einstein-Str. 23-24, D-18059 Rostock, Germany [email protected] For the first time photoelectron spectroscopy (PES) has been applied to multiply negatively charged metal clusters. Singly-charged anionic silver clusters were produced in a magnetron sputter source, size-selected and captured in a linear Paul trap, operated in the “digital trapping mode” with field-free periods. This allowed the attachment of further electrons to the clusters. Up to six additional electrons, depending on the number n of atoms in the cluster, could be added, i.e. charge states up to z = -7 were reached. The cluster ions were then ejected from the Paul trap, accelerated and transferred to a photoelectron spectrometer. On their way, the ion bunch separated according to the different charge states. Thus, size and charge-state selected clusters have been addressed by the measurements. PES was performed with a magnetic-bottle time-of-flight spectrometer.
Figure 1: Photoelectron spectra of a mono-, di-, tri-,and tetra-anionic (z = -1, -2, -3, -4) $J= silver clusters Q of size n = 209, measured in a magnetic-bottle time-of-flight spectrometer at laser wavelength of 266nm.
As an example, Fig. 1 shows photoelectron spectra of polyanionic silver clusters of size n = 209. The electron binding energy decreases as a function of (negative) charge state. For 4 Ag 209 it is negative, i.e. the energetically highest electrons are no longer bound but in a metastable state – a new observation for metal clusters. We have studied this phenomenon for various cluster sizes and charge states. In addition, the laser-pulse energy as well as the photon energy was varied. This gives further insight into the nature of polyanionic metal clusters, in particular with respect to the Coulomb barrier. The data is currently under evaluation.
The project was funded by the Collaborative Research Center (SFB) 652 of the DFG.
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Thursday, Auguest 16th 2018
Session XI (Session chair: Hannu Häkkinen) 8:00 – 8:40 Ligand-Protected Clusters Beyond Nano: From Molecules to Assemblies Katsuaki Konishi 8:40 – 9:20 New Nanomaterials for Energy Storage Haoshen Zhou 9:20 – 9:40 Mechanism of Chirality Transfer from the Gold Surface to the Thiolate Monolayer in Au38(SR)24 Cluster Giovanni Salassa
9:40 – 10:00 Discovery of Chiral Golden Fullerenes: I–Z60 Robert Whetten 10:00 – 10:30 Break Session XII (Session chair: La-Sheng Long) 10:30 – 11:10 Molecular Chirality and the Electron’s Spin-The Ultimate Nano Spintronics Ron Naaman 11:10 – 11:30 Giant Magnetoelectric Effect in Pseudo 1–3 Heterostructural Films with FeGa Nanocluster- Assembled Micron Scale Discs Embedded into Bi5Ti3FeO15 Matrices Shifeng Zhao 11:30 – 11:50 Interface and Local Environment Dominate Plasmonic Quantum Size Effects in Silver Nanoparticles Matthias Hillenkamp
11:50 – 12:10 Semiconducting A2B2XY (A = Si-Pb, B = Cl-I, and XY = PN and SiS) Inorganic Double Helices: Electronic and Atomic Structures from Ab Initio Calculations Vijay Kumar 12:10 – 13:30 Lunch Session XIII (Session chair: Bernd von Issendorff) 13:30 – 14:10 Molecular and Cluster Dipoles in Superfluid Helium Nanodroplets Vitaly Kresin 14:10 – 14:50 Spectroscopy and Mass Spectrometry of Molecules and Clusters in Helium Nanodroplets Michael Gatchell 14:50 – 15:10 Atomic Gold Ions Clustered with Noble Gases Olof Echt 15:10 – 15:30 Magnetism and Electronic Correlations in Small Clusters: From Kramers Degeneracy to Non- Heisenberg Covalent Exchange Andrei Kirilyuk 15:30 – 16:00 Break Session XIV (Session chair: Ken Judai) 16:00 – 16:40 Fabrication of Biomimetic Complex Systems by Supersonic Cluster Beam Deposition: From Soft Actuation to Neural Computing Paolo Milani 16:40 – 17:20 New Radiation Detector Made by Nanoclusters for Nuclear Energy Application You Qiang 17:20 – 17:40 Systematic Investigation of Gold Nanocluster – Superstructures with Atomistic Molecular Dynamics Simulations Emmi Pohjolainen 17:40 – 18:00 MOSP: Multiscale Operando Simulation Package for Nanoparticles Beien Zhu 18:00 – 20:00 Poster Session B
Thursday August 16th INV15
Ligand-protected clusters beyond nano: From molecules to assemblies
Katsuaki Konishi Graduate School of Environmental Science and Faculty of Environmental Earth Science, Hokkaido University, Sapporo, 060-0810, Japan
Ligand-protected gold clusters with defined compositions and structures have attracted special attention because of the unique optical/electronic properties associated with their molecule- like features. During the studies on subnanometer-sized gold clusters (nuclearity ~10) protected by phosphines, we have found several clusters with unusual geometric structures and optical properties, and shown that not only the nuclearity but also the geometries of the inorganic frameworks have profound effects on their optical properties [1]. In this presentation, we show additional factors effective in the modulation of the optical properties. In small ligand-protected gold clusters, most of the gold atoms are located on the inorganic surface, so the surrounding ligand environments would affect the cluster properties. In fact, systematic experimental studies of phosphine-coordinated gold cluster family revealed that the ligand moieties have critical effects on the absorption and photoluminescence properties. It should be noted that not only the “through-bond” electronic effects of coordinating atoms but also the nonbonding interaction with neighboring organic units cause substantial perturbations [2]. The proximal π-systems also affect the optical properties through the electronic coupling with the gold moieties. These findings demonstrate that the ligand moieties at the exterior of gold clusters are no more just protecting units but can be used as “toolboxes” for the modulation of cluster properties. We also found that the cluster aggregation event sometimes causes significant alterations of the absorption and photoluminescence properties [3]. As an example, core+exo type Au8 clusters exhibited a fluorescence type emission in the monomeric form, whereas a red-shifted phosphorescence-type emission with an enhanced intensity was observed for the cluster aggregates. Studies coupled with the excitation spectra suggested that the phosphorescence-type emission was observed specifically when cluster molecules are aligned in particular orientations.
[1] Konishi, K. Struct. Bonding 2014, 49, 161; Kamei, Y.; Shichibu, Y.; Konishi, K. Angew. Chem. Int. Ed. 2011, 50, 7442; Shichibu, Y.; Kamei, Y.; Konishi, K. Chem. Commun. 2012, 48, 7559; Shichibu, Y.; Zhang, M.; Kamei, Y.; Konishi, K. J. Am. Chem. Soc. 2014, 136, 12892. [2] Kobayashi, N.; Kamei, Y.; Shichibu, Y.; Konishi, K. J. Am. Chem. Soc. 2013, 135, 16078 (JACS spotlights); Sugiuchi, M.; Shichibu, Y.; Nakanishi, T.; Hasegawa, Y.; Konishi, K. Chem. Commun. 2015, 51, 13519; ]Konishi, K.; Iwasaki, M.; Sugiuchi, M.; Shichibu, Y. J. Phys. Chem. Lett. 2016, 7, 4267; Bakar,M. A.; Sugiuchi, M.; Iwasaki, M.; Shichibu, Y.; Konishi, K. Nature Commun. 2017, 8, 576. [3] Sugiuchi, M.; Maeba, J.; Okubo, N.; Iwamura, M.; Nozaki, K.; Konishi, K. J. Am. Chem. Soc. 2017, 139, 17731.
19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Thursday August 16th INV16
Post Lithium-ion Batteries: Na-ion, Li-S, and Li-Air Batteries
Haoshen Zhou Nanjing University, China & National institute of Advanced Industrial Science and Technology, Japan
The key technology for the low carbon society is to develop energy storage device. However, now’s Li-ion battery can’t satisfy the industrial needs resulted from the electric vehicle and the smart grid power storage system. Recently, the post Li-ion batteries including Na-ion, Li-S, and Li-air batteries have been investigated as alternative rechargeable batteries , which have attracted much more attention. We also investigated Na-ion, Li-S, and Li-air batteries in my research group. There is a great interest in developing sodium-ion batteries (SIBs) for large scale application due to the low cost and almost infinite supply of sodium. Owing to large specific capacity and reversible insertion/extraction, sodium metal oxide NaxMeO2 (Me = 3d transition metal) has been focus of study on sodium-ion batteries. We also developed new type Li-S batteries based on new MOF separators which can block 2- the discharge products Sn (4 REFERENCES 1. Songyan Bai, Haoshen Zhou, et. al., Nature Energy, 1, (2016), 16094. 2. Shaohua Guo, Haoshen Zhou, et. al., Nature Communications, 2017, 8, 135 3. Shichao Wu, Haoshen Zhou, et. al., Nature Communications, 8, (2017), 15607. 4. Fujun Li, Haoshen Zhou, et. al., Nature Communications, 6, (2015), 7843 5. Yu Qiao, Haoshen Zhou, et. al., Angewandte Chemie International Edition, 56, (2017), 4960. 6. Shaohua Guo, Haoshen Zhou, et. al., Angewandte Chemie International Edition, 54, (2015), 11701. 7. Shaohua Guo, Haoshen Zhou, et. al., Angewandte Chemie International Edition, 54, (2015), 5894. 8. Na Li, Haoshen Zhou, et. al., Angewandte Chemie International Edition, 54, (2015), 9271. 9. Haijun Yu, Haoshen Zhou, et. al., Angewandte Chemie International Edition, 53, (2014), 8963. 10. Zelang Jian, Haoshen Zhou, et. al., Angewandte Chemie International Edition, 53, (2014), 442. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Thursday August 16th HT24 Mechanism of chirality transfer from the gold surface to the thiolate monolayer in Au38(SR)24 cluster 1 2 2 3 3, L. Riccardi, F. Rastrelli, F. De Biasi, T. Bürgi, G. Salassa, * 1 Istituto Italiano di Tecnologia IIT, Italy 2 Dipartimento di Scienze Chimiche, University of Padua, Italy 3 Département de Chimie Physique, University of Geneva, Switzerland Small gold nanoparticles or clusters are core-shell systems characterized by a diameter smaller than 2 nm (up to 200 Au atoms). In some cases, like Au38(SR)24, these clusters possess an intrinsic chirality (absence of stereocenters in the protecting ligands). The chirality, in this case, arises from the pattern created by the distribution of the staple motifs on the surface of the cluster (“staples” = bonding mode between thiolates and gold surface through a linear S-Au(I)- S complex). Au38(SR)24 have a face-fused biicosahedral Au23 core surrounded by and protected by 3 short Au(SR)2 and 6 long Au2(SR)3 staples (Figure 1).[1] The long staples form triblade fans at the poles, that either rotate clockwise or anti-clockwise, creating the chiral arrangement. Vibrational circular dichroism measurements demonstrate a chirality transfer from the surface of the cluster to the non-chiral protecting thiolate.[2]. Figure 1: Au38(SR)24 structure and schematic representation of the chirality transfer. Here for the first time we clarified the mechanism of chirality transfer through a mixed NMR- molecular dynamic approach. In particular, alkyl molecules (e.g. butanethiol or phenyl ethane thiol) bound to particular position on the surface of Au38 are forced to adopt chiral conformations (i.d. gauche +/-, Fig 1). The asymmetric environment created on the surface enhance the probability of chiral conformations in respect of the others. The chirality transfer observed in Au38 could be exploited in the creation of nanosystems with a dynamic chiral monolayer that could potentially applied in sensing and catalysis. [1] I. Dolamic, S. Knoppe, A. Dass, T. Bürgi Nat. Commun., 2012, 3, 798. [2] I. Dolamic, B. Varnholt, T. Bürgi Nat. Commun., 2015, 6, 7117. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Thursday August 16th HT25 Discovery of Chiral Golden Fullerenes: I–Z60 Robert L. Whetten, David M. Black, Marcos M. Alvarez Department of Physics & Astronomy, University of Texas, San Antonio, TX, 78249 USA [email protected] The 1990 discovery of molecular solids rich in Ih-C60 clusters was a crucial moment reported first at ISSPIC-5 in Konstanz. Here we report on a development, comparable in several key respects, in cluster-compounds of noble-metal atoms: During experiments aimed at under- standing the geological and microbial origins of metallic gold, aurous-thiolate (AuX) has been reduced and the products analyzed by electrospray volatilization, leading to the accumulation of a remarkably abundant cluster compound comprising precisely 60 anionic ligands (X-) and 144 gold atoms. Concerning the question of what kind of 204-atom structure might give rise to such a ubiquitous species, we suggest a sextuple-strand woven sphere in which the 60 X- sites occupy vertices of the snub-dodecahedron, and are linked in coordinative zig-zag (Z) fashion to 120 Au-sites. This object is commonly encountered as the traditional woven-reed football (cf. Figure below) of Southeast Asia, whose exceptional stability was noted by Fuller & Edmundson and mathematized by Nishiyama. The remaining 24-Au are distributed four to each of the six 5-fold axes, acting to cement the structure. This resulting filled Z60 structure, Z= Au2X, thus has all valences satisfied, has chiral-icosahedral (I) symmetry, and appears to be mechanically resilient as well as maximally compact, accounting for the observed resistance to chemical attack. As will be described in this presentation, key features of this structure were antici-pated in the works of ISSPIC pioneers Farges, Dahl, and Martin; whereas Tsukuda & coworkers advanced the precise determination of composition & structure. New evidence is presented that compounds having this unique structure can account for results from many labs concerned with products, typically described as “~2.0-nm gold nano- particles”, as recent advances in analytical methods have enabled such determinations. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Thursday August 16th INV17 Molecular Chirality and the Electron’s Spin- The Ultimate Nano Spintronics Ron Naaman, Department of Chemical and Biological Physics Weizmann Institute, Rehovot 76100, Israel Spin based properties, applications, and devices are commonly related to magnetic effects and to magnetic materials. However, we found that chiral organic molecules act as spin filters for photoelectrons transmission,1 in electron transfer,2 and in electron transport.3 The new effect, termed Chiral Induced Spin Selectivity (CISS),4,5 was found, among others, in bio-molecules and in bio-systems. 6 It has interesting implications for the production of new types of spintronics devices7,8 and on producing efficient electron transfer systems. The basic effect will be explained and various applications and implications will be discussed. References: [1] Göhler, B.; Hamelbeck, V.; Markus, T.Z.; Kettner, M.; Hanne, G.F.; Vager, Z.; Naaman, R.; Zacharias, H. Science 2011, 331, 894. [2] Mishra, D.; Markus, T.Z.; Naaman, R.; Kettner, M.; Göhler, B.; Zacharias, H.; Friedman, N.; Sheves, M.; Fontanesi, C. PNAS, 2013, 110, 14872. [3] Xie, Z.; Markus, T. Z.; Cohen, S. R.; Vager, Z.; Gutierrez, R.; Naaman, R. Nano Letters, 2011, 11, 4652. [4] Naaman, R.; Waldeck, D.H. J. Phys. Chem. Lett. (feature) 2012, 3, 2178. [5] R. Naaman, D. H. Waldeck, Spintronics and Chirality: Spin Selectivity in Electron Transport Through Chiral Molecules, Ann. Rev. Phys. Chem. 2015, 66, 263–81. [6] I. Carmeli, K. S. Kumar, O. Hieflero, C. Carmeli, R. Naaman, Angew. Chemie 2014, 53, 8953 –8958. [7] O. Ben Dor, S. Yochelis, A. Radko, K. Vankayala, E. Capua, A. Capua, S.-H. Yang, L. T. Baczewski, S. S. P. Parkin, R. Naaman, and Y. Paltiel, Nat. Comm. 8:14567 (2017). [8] K. Michaeli, V. Varade, R. Naaman, D. Waldeck, Journal of Physics: Condensed Matter, 29, 103002 (2017) 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Thursday August 16th HT26 Giant magnetoelectric effect in pseudo 1–3 heterostructural films with FeGa nanocluster- assembled micron scale discs embedded into Bi5Ti3FeO15 matrices Yulong Bai, Ning Jiang, Shifeng Zhao School of Physical Science and Technology, Inner Mongolia University, PR China Cluster-assembled FeGa micron scale discs prepared by low energy cluster beam deposition were embedded into Bi5Ti3FeO15 matrices to form pseudo 1-3 heterostructural films. Such structure is different from the common 1-3, 2-2, 0-3 connectivity types as shown in Figure 1 (a), which efficiently avoids the weakness, such as the clamping effect of substrate, piezoelectric degeneration and high leakage current.[1] Well ferroelectric, piezoelectric, ferromagnetic properties and giant magnetoelectric effect are achieved for the heterostructural films, which is ascribed to the depression of the clamped effect from the hard substrate for such pseudo 1-3 structures and the multi-interface coupling between large magnetostrictive coefficient of FeGa micron scale discs and high piezoelectric coefficient of circle surrounding Bi5Ti3FeO15 matrices. So strong interface strain coupling between the micron discs and the inhomogeneously multiferroic matrix induces obvious magnetoelectric coupling behaviors. The real scale finite element analysis model is chosen to calculate the local coupling. After modified by the electromechanical coupling factor κ33, the calculation and experimental values for magnetoelectric coefficients αE33 are identical and with the same change trend. The present work provides a potential way to fabricate clamped-free magnetoelectric films for microdevice applications. Figure 1 (a) The comparison of different connectivity types; (b) magnetoelectric effect coefficient αE33 as a function of bias magnetic field for experiment, calculated values and modified by κ33 factors, the inset presents κ33 factors depended on magnetic field. (c) simulation results of surface displacement, surface strain and magnetoelectric voltage. [1] M. H. Li, A. Matyushov, C. Z. Dong, H. H. Chen, H. Lin, T. X. Nan, et. al., Appl. Phys.Lett., 2017, 110, 143510. [2] Y. L. Bai, N. Jiang, S. F. Zhao, Nanoscale, 2018 DOI: 10.1039/C7NR09652F. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Thursday August 16th HT27 Interface and Local Environment Dominate Plasmonic Quantum Size Effects in Silver Nanoparticles A. Campos1, N. Troc2, E. Cottancin2, M. Pellarin2, H.-Ch. Weissker3, J. Lermé2, M. Kociak1, 2,4 M. Hillenkamp 1 Laboratoire de Physique des Solides, UMR8502 CNRS/Université Paris-Sud, Orsay, France 2 Institute of Light and Matter, University of Lyon 1/CNRS, UMR5306, Villeurbanne, France 3 Aix Marseille University, CNRS, CINaM UMR 7325, 13288, Marseille, France 4 Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, Campinas, Brazil [email protected] The physical properties of metals change when their dimensions are reduced to the nano-scale and new phenomena like the Localized Surface-Plasmon Resonance (LSPR) appear. This collective electronic excitation can be tuned over a large spectral range by adapting the material, size and shape. The existing literature is as rich as controversial as e.g. size-dependent spectral shifts of the LSPR in small metal nanoparticles, induced by quantum effects, are reported to the red, to the blue or entirely absent. Here we report how complementary experiments on mass- selected small silver nanoparticles embedded in silica can yield inconsistent results on the same system: while optical absorption shows no size-effect in the range between only a few atoms and ~10 nm, a clear spectral shift is observed in single-particle electron spectroscopy. Our quantitative interpretation, based on a mixed classical/quantum model, resolves the apparent contradictions, not only within our experimental data, but also in the literature. Our comprehensive model describes how the local environment is the crucial parameter controlling the manifestation or absence of size effects. Figure 1a) Optical spectroscopy for silver nanoparticles of varying size embedded in silica matrices. b) Scanning Transmission Electron Microscopy image of a 2.0 nm diameter particle and the associated Electron Energy Loss spectrum in the blue surface region of interest. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Thursday August 16th HT28 Semiconducting A2B2XY(A=Si-Pb, B = Cl-I, and XY = PN and SiS) Inorganic Double Helices: Electronic and atomic structures from ab initio Calculations T.K. Bijoya,b, P. Muruganb,c and Vijay Kumara,d aDr. Vijay Kumar Foundation, 1969 Sector 4, Gurgaon 122001, Haryana, India bAcademy of Scientific and Innovative Research (AcSIR)-CSIR-Central Electrochemical Research Institute, Karaikudi 630003, Tamil Nadu, India cFunctional Materials Division- CSIR-Central Electrochemical Research Institute, Karaikudi 630003, Tamil Nadu, India dCenter for Informatics, School of Natural Sciences, Shiv Nadar University, NH-91, Tehsil Dadri, Gautam Buddha Nagar 201314, Uttar Pradesh, India Recently semiconducting inorganic double helices of SnIP have been produced [1]. Here we present the atomic structure as well as electronic properties of new classes of DNA-like inorganic double helices A2B2XY (A = Si-Pb, B = Cl-I, and XY = PN and SiS) by employing density functional theory (DFT) calculations including van der Waals interactions. In these quaternary double helices the inner helix is made up of PN or SiS while the outer helix is AB which is connected with the inner helix [2]. The former wraps around the inner helix. All these helices are semiconducting and in some cases these are direct band gap semiconductors. The atomic structures of the different double helices including SnIP type have been analysed in detail to understand the stability of these systems. We find that the difference in the interatomic bond lengths in the two helices is up to about 80% which is remarkable. The use of PN and SiS inner helices gave up opportunity to study the flexibility in this structure as the bond lengths and charge transfer can be varied since the inner helix has polar covalent bonding. Bader charge and bond order analysis shows strong covalent bonding in the inner helix. Further calculations on assemblies of these double helices will be reported [3]. [1] D. Pfister, K. Schäfer, C. Ott, B. Gerke, R. Pöttgen, O. Janka, M. Baumgartner, A. Efimova,A. Hohmann, P. Schmidt, S. Venkatachalam, L. van Wüllen, U. Schürmann, L. Kienle, V. Duppel,E. Parzinger, B. Miller, J. Becker, A. Holleitner, R. Weihrich and T. Nilges, Adv. Mater., 28, 9783 (2016). [2] T.K. Bijoy, P. Murugan and V. Kumar, Phys. Chem. Chem. Phys. 20, 10060 (2018). [3] T.K. Bijoy, P. Murugan and V. Kumar, to be published. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Thursday August 16th INV18 Molecular and cluster dipoles in superfluid helium nanodroplets Vitaly Kresin Department of Physics and Astronomy, University of Southern California, USA The use of external fields to orient, polarize, deflect, and trap individual polar molecules and clusters originated in the early years of quantum mechanics and has remained continuously relevant through today’s research on novel quantum matter, atomic and molecular clusters, elemental chemical reaction processes, and quantum computers based on cold polar molecules. However, ultracold trapping has been achieved only for a small number of diatomic molecules, while supersonic expansions typically produce species with internal temperatures above several Kelvins. On the other hand, by embedding polar molecules in a beam of superfluid helium nanodroplets one can reduce their temperatures to below 400 mK, and in this case the application of an external static field transforms their rotations into pendular motion, achieving nearly full orientation of the dipoles. I will describe how this extremely high degree of orientation can be exploited in beam deflection experiments where even massive neutral nanodroplets experience remarkably large electrostatic deflections when doped with just a single polar molecule [1,2]. This approach is applicable to a wide variety of molecules and makes it possible to determine, in a direct manner, the dipole moments of molecules and small clusters that are difficult to obtain by other methods. In addition, it provides a means to size- separate the fragile neutral nanodroplets. The measurements also supply evidence for the formation of highly polar systems by dipoles assembling into aligned structures within the droplets. [1] D. J. Merthe and V. V. Kresin, “Electrostatic deflection of a molecular beam of massive neutral particles: Fully field-oriented polar molecules within superfluid nanodroplets,” J. Phys. Chem. Lett. 7, 4879 (2016). [2] J. W. Niman, L. Kranabetter, B. Kamerin, D. J. Merthe, and V. V. Kresin, to be published. This work is supported by the US National Science Foundation (CHE-1664601). 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Thursday August 16th INV19 Spectroscopy and mass spectrometry of molecules and clusters in helium nanodroplets M. Gatchell1,2, M. Goulart1, A. Kaiser1, L. Kranabetter1, M. Kuhn1, P. Martini1, A. Mauracher1, J. Postler1, and P. Scheier1 1 Institute for Ion Physics and Applied Physics, University of Innsbruck, Austria 2 Department of Physics, Stockholm University, Sweden We have used superfluid He nanodroplets to produce and study molecules and clusters by means of mass spectrometry and messenger spectroscopy techniques. In recent studies we have investigated the structures of weakly bound atomic and molecular clusters and how they are influenced by the specific carriers of charge within the cluster. For example, we have observed that protonated noble gas clusters have structures more akin to neutral clusters than purely cationic ones do, the structures of which are often poorly explained by the sphere packing models that are commonly used [1]. We have also used He atoms as messengers for spectroscopy measurements on complex + + molecules such as C60 and corannulene (C20H10 ) [2,3]. In these measurements we find that the simple, linear shift of electronic transition energies as a function of the number of taggant atoms + on C60 is not reproduced for corannulene, making an accurate estimate of the gas phase cation spectrum more difficult in the latter case. In my talk I will be highlighting some of our most recent results on these subjects as well as new experiments where we study the fragmentation of He droplets containing more than 10 million atoms. + Figure 1: Left: Protonated Ar13 cluster with an icosahedral structure. Right: Corannulene (C20H10) molecule with a He tag atom situated above the center pentagonal ring on the concave side of the molecule. [1] M. Gatchell et al., submitted 2018 [2] A. Kaiser et al., J. Phys. Chem. Lett., 9, 1237 (2018) [3] M. Kuhn et al., Nat. Commun., 7, 13550 (2016) 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Thursday August 16th HT29 Atomic Gold Ions Clustered with Noble Gases M. Goulart1, P. Martini1, L. Kranabetter1, M. Gatchell1, A. Mauracher1, A. Kaiser1, P. Scheier1, O. Echt1,2 1 Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Austria 2 Physics Department, University of New Hampshire, Durham, USA Au+ ions form strong chemical bonds with the heavy noble gases (Ng) argon, krypton, and + xenon but the nature of the bond is still being debated [1,2]. Ng2Au ions have been predicted to + be particularly stable [3], about twice as stable as Ng3Au [4]. They possess linear equilibrium structures with Dfh symmetry. Experimental data, however, are largely restricted to complexes containing just one noble gas atom [5]. 0 5 10 15 12 We report high-resolution mass spectra of helium 4 + a) HenAu nanodroplets doped with gold and noble gases; the + + 2 droplets are ionized by electrons. HenAu , NenAu , + + + ArnAu , KrnAu , and XenAu ions are observed. The most 0 12 + prominent anomalies in the abundance distributions of b) NenAu + + 20 KrnAu and XenAu (Fig. 1) are local maxima at n = 2, 2 confirming their high stability. The abundance distribution 10 + of ArnAu whose bonds are predicted to have a much 0 weaker covalent component also features a maximum at n 10 2 6 9 c) Ar Au+ = 2. Several other anomalies appear as well. n + 5 Surprisingly, the abundance distribution of NenAu features a local maximum at n = 2, too; this is not 0 consistent with the notion that the very weakly bound 40 2 + + + d) KrnAu NeAu and Ne2Au have no genuine covalent bond [2,3]. Ion abundance (arb. units) If an atomic ion is solvated in a cluster of noble gas atoms 20 and the bonding is purely physical, non-directional, the 0 geometric structure of the cluster will critically depend on 2 e) Xe Au+ the ratio V of the ion-ligand versus the ligand-ligand n 20 distance [6]. For He (V = 0.97) and Ne (0.85) the values are in the range where icosahedral packing is favored, 0 0 5 10 15 consistent with the anomaly at n = 12. The value of Ar Cluster size n (0.67) would favor octahedral packing which provides a Fig. 1: Abundance distributions + rational for the anomaly at n = 6; the anomaly at n = 9 of NgnAu cluster ions. may be tentatively assigned to the capped square antiprism [6]. [1] P. Pyykkö, Chem. Soc. Rev. 37, 1967 (2008); T. Zeng and M. Klobukowski, J. Phys. Chem. A 112, 5236 (2008) [2] W. H. Breckenridge, V. L. Ayles, and T. G. Wright, J. Phys. Chem. A 112, 4209 (2008). [3] S. J. Grabowski, J. M. Ugalde, D. M. Andrada, and G. Frenking, Chem. Eur. J. 22, 11317 (2016). [4] X. Y. Li, X. Cao, and Y. F. Zhao, Aust. J. Chem. 62, 121 (2009); X. Y. Li, X. Cao, and Y. F. Zhao, J. Phys. B 42, 065102 (2009); X. Y. Li, X. Cao, and Y. F. Zhao, Theor. Chem. Acc. 123, 469 (2009). [5] D. Schröder, H. Schwarz, J. Hrusak, and P. Pyykkö, Inorganic Chemistry 37, 624 (1998); R. J. Plowright et al., J. Phys. Chem. A 114, 3103 (2010). [6] D. Prekas, C. Lüder, and M. Velegrakis, J. Chem. Phys. 108, 4450 (1998). 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Thursday August 16th HT30 Magnetism and electronic correlations in small clusters: from Kramers degeneracy to non-Heisenberg covalent exchange A. Diaz Bachs, L. Peters, V. Chernyy, R. Logemann, J.M. Bakker, M.I. Katsnelson, and A. Kirilyuk FELIX Laboratory, Radboud University, 6525 ED Nijmegen, The Netherlands [email protected] In this work we present a comprehensive study of the mechanisms governing the behavior of magnetic moments in small clusters, pure as well as doped with single impurities. Particularly in Co-doped Nb and V clusters, our magnetic deflection experiments demonstrate a strong size dependence of magnetic properties, with large magnetic moments in some clusters, and fully non-magnetic behavior of others. On the other hand, theory demonstrates a very strong non- Heisenberg behavior of the magnetic exchange in FenOm. The first experimental challenge is to obtain exact geometries of the clusters, as very few techniques are available. We solve this by measuring the cluster's vibrational spectra at the FELIX free electron laser, and then fit them with those obtained from DFT calculations [1,4]. From the theoretical perspective, the difficulty in explaining the observed magnetic behavior is in the treatment of the electronic correlations. One could expect correlations to be stronger in small clusters than in the bulk due to a stronger localization of the wave-functions. Thus, in order to obtain a physical understanding of the experimentally observed magnetic behavior of dopants, we perform an analysis based on the Anderson impurity model [2,3], that in our case corresponds to a strong impurity-host interaction. It is found that the absence of the magnetic moment is not due to the Kondo effect [4]. Moreover, the magnetic behavior of the Co impurity is directly related to the effective hybridization around the chemical potential: large hybridization effectively quenches the magnetic moments. Replacing Co dopants with Tb ones results in strong magnetic moments of clusters of all sizes, which is clearly in agreement with the effective hybridization mechanism. Most interestingly, many Co-doped clusters with quenched magnetic moment but with a single unpaired electron, show a deflection profile which is exactly the same as that of a single atom. Namely, the cluster beam splits in two, corresponding to spin-up and spin-down states. The same is observed in many undoped Nb and V clusters as well [5]. This is a result of Kramers degeneracy theorem for systems with a half-integer spin. This purely quantum phenomenon is surprisingly observed for large systems of more than 20 atoms, and also allows to study various quantum relaxation processes, via Raman two-phonon and Orbach high-spin mechanisms. Strong variations of exchange interaction are found in FexOy0/+ clusters, that also show unusually strong spin polarization on O sites depending on the magnetic configuration of the cluster [6]. The exchange interactions in clusters show non-Heisenberg behavior, which is attributed to covalent magnetism since the hybridization between Fe 3d and O 2p orbitals for clusters is much stronger than in hematite and depends on the magnetic configuration. [1] R. Logemann, G. A. de Wijs, M. I. Katsnelson, and A. Kirilyuk, Phys. Rev. B 92, 144427 (2015). [2] P.W. Anderson, Phys. Rev. 124, 41 (1961). [3] K. Hirsch et al., Phys. Rev. Lett. 114, 087202 (2015). [4] A. Diaz Bachs et al., Phys. Rev. B 97, 134427 (2018). [5] A. Diaz Bachs, M.I. Katsnelson, and A. Kirilyuk, New J. Phys. 20, 043042 (2018). [6]R. Logemann, A.N. Rudenko, M.I. Katsnelson, and A. Kirilyuk, to be published 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Thursday August 16th INV20 Fabrication of Biomimetic Complex Systems by Supersonic Cluster Beam Deposition: from Soft Actuation to Neural Computing Paolo Milani CIMAINA and Department of Physics, University of Milano, Italy The convergence of top-down microfabrication with bottom-up assembling of nano-objects makes compatible different length scales, architectures, materials, manufacturing methods. In particular the integration of nanoparticles and/or nanostructured layers on microfabricated platforms and polymeric substrates is the basis for the production of a novel class of devices capable of sensing, data and energy storage, actuation [1]. The use of supersonic cluster beam deposition (SCBD) and implantation (SCBI) is currently an enabling tool for the large-scale integration of nanoparticles and nanostructured films on microfabricated platforms and smart nanocomposites [1]. Here I present the synthesis, fabrication and characterization of different systems obtained with SCBD and SCBI such as electroactive soft actuators [2], planar microsupercapacitors [3], cluster-assembled films with memristive switching properties [4], networks for fabrication of neural circuits [5]. These elements can be integrated in a single platform paving the way to the production of a new class of multifunctional devices. Figure 1: SCBD fabrication of microsupercapacitors on paper. From ref. 3 [1] P. Milani, L.G. Bettini, Nano- and Micro-manufacturing with nanoparticles produced in the gas phase: an emerging tool for function and length scale integration in Y. Huttel (ed.), Gas-Phase Synthesis of Nanoparticles, Wiley-VCH (2017) [2] Y. Yan, et al., Adv. Mater. 29, 1606109 (2017) [3] L.G. Bettini, et al., Flex. Print. Electron. 2, 025002 (2017) [4] C. Minnai, et al., Nano Futures 2, 011002 (2018) [5] C. Schulte, et al., Acc. Chem. Res. 50, 231 (2017) 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Thursday August 16th INV21 NEW RADIATION DETECTOR MADE BY NANOCLUSTERS FOR NUCLEAR ENERGY APPLICATION 1: Physics Department, University of Idaho, Moscow ID, USA, 2: Center of Advanced Energy Study, Idaho National Laboratory, Idaho Falls ID, USA Abstract Nano-Nuclear Technology (NNT) deals with the use of engineered-nanomaterials for the improvement of performance and safety of the future generation nuclear reactors. This talk is focused on the fundamental understanding of fast responses in-situ and ex-situ on nanostructure evolution, magnetic and electrical property changing of nanocluster-assembled materials under irradiations by use of He+, heavy (Si2+) ion beam and e-beam. The investigations of highly radiation sensitivity and super-stability up to 800 oC were performed in detail on Fe-based core-shell nanocluster films. The investigation results show that the nanocluster materials are excellent candidates for the nuclear radiation detection and radiation environment applications. The investigation is leading for the development of highly sensitive new type of radiation detector and monitor in nuclear energy application. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Thursday August 16th HT31 Systematic Investigation of Gold Nanocluster – Superstructures with Atomistic Molecular Dynamics Simulations 1 1 2 1,2 E. Pohjolainen , S. Malola , G. Groenhof , H. Häkkinen 1 Department of Physics, Nanoscience Center, University of Jyväskylä, Finland 2 Department of Chemistry, Nanoscience Center, University of Jyväskylä, Finland Self-assembly of atomically precise metal nanoclusters into ordered superstructures, controlled by characteristics of the protecting ligand shell and solvent conditions, provide an interesting set of new materials [1-3]. To elucidate the formation and stability of Au102pMBA44 gold nanocluster self-assembled into 2D hexagonally packed crystals and spherical shells [1], we have performed atomistic molecular dynamics simulations of such two types of superstructures in several different conditions [4]. In addition to significant differences observed in superstructure stabilities in varying solvent conditions, we also investigated the effect of the protonation state of the protecting pMBA shell of the gold clusters, i.e., generating different types of patchiness on the cluster surfaces. Figure 1: Effect of different simulated solvent conditions (b)-(f) on the spherical shell structure (a). [1] Nonappa, T. Lahtinen, J. S. Haataja, T.-R. Tero, H. Häkkinen, O. Ikkala, Angew. Chem. 2016, 128, 16269. [2] Nonappa, J. S. Haataja, J. V. I. Timonen, S. Malola, P. Engelhardt, N. Houbenov, M. Lahtinen, H. Häkkinen, O. Ikkala, Angew. Chem. 2017, 129, 6573. [3] Chakraborty, A. , Fernandez, A. ., Som, A. , Mondal, B. , Natarajan, G. , Paramasivam, G. , Lahtinen, T. , Häkkinen, H. , Nonappa, N. and Pradeep, T., Angew. Chem. Int. Ed. 2018, 1. [4] E. Pohjolainen et al. Manuscript in preparation. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Thursday August 16th HT32 MOSP: Multiscale Operando Simulation Package for Nanoparticles Yi Gao,* Beien Zhu, Jun Meng, Jifeng Du Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, 201800 China Email: [email protected] Abstract The structures of the metal nanoparticles are crucial for their catalytic activities. How to understand and even control the shape evolution of nanoparticles under reaction condition is a big challenge in heterogeneous catalysis. It has been proved that many reactive gases/liquids hold the capability of changing the structures and properties of metal nanoparticles. However, despite the experimental achievements, the understanding and precise prediction of these structural evolutions is still a challenging and demanding task. Herein, we developed Multi-scale Operando Simulation Package (MOSP) to quantitatively simulate the static and dynamic structural evolution of metal nanoparticles under different experimental conditions, including size, composition, temperature, pressure, gas/liquid, gas mixtures and supports. Our software offers possibilities for obtaining atomic-scale structures and insights beyond the experimental limits. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Friday, Auguest 17th 2018 Session XV (Session chair: Feng Yin) 8:00 – 8:40 Syntheses of Boron Clusters and Their Applications Xuenian Chen 8:40 – 9:00 Size-Specific Interaction between Isolated Gold Clusters and Graphene Devices Ewald Janssens + 9:00 – 9:20 Interaction of Swift H2 Cluster Beam with Thin Layer Graphene Foils Jifeng Han 9:20 – 9:40 Low-Temperature Dissociation of NO Molecule in Catalytic Reduction on Size-Selected Platinum Cluster Disk Bound to Silicon Substrate Hisato Yasumatsu 9:40 – 10:00 Reduced Sintering of Mass-Selected Au Clusters on SiO2 by Alloying with Ti Yubiao Niu 10:00 – 10:30 Break Session XVI (Session chair: Min Han) 10:30 – 10:50 Research on Electronic Correlation Properties of Low Dimensional Rhodium Qinfang Zhang 10:50 – 11:10 Silver-Copper Oxides: Are the Hopes for Superconductivity Over? Maxim Tchaplyguine 11:10 – 11:40 Summary Talk Peter Lievens 11:40 – 11:50 ISSPIC XX Robert Whetten 11:50 – 12:00 Closing Min Han & Lai-Sheng Wang 12:00 Adjourn Friday August 17th INV22 -#( ''$ $&$#!)'(&'# &%%! ( $#' 3 # #/ #3# )/)# # #6 ## - $&($&-$ $&$# " '(&-#*##& - (& !'/ $$!$ " '(&-# " !# #& # /## $&"!# *&' (-/ #, # /##/>?=::A/ # ,# #7 ()2)2# $&$# !)'(&' & "%$&(#( "(& !' # "#- !'/ ') ' -&$ # '($& "(& !'/ $&$#3 $#( # # %$!-"&"(& !'/$&$##)(&$#%()&( &%-4 5/#'$! $#$#)($&'2 ' $&$#!)'(&'&)')!!-'-#( ' .-$##'( $#&( $#$ ( $&$ -& '(!*( ("%&()&'2; (& #*'( ( # & )!!-'*&!(-%'$ $##'( $#&( $#'/+ * $)# < ( $&"( $# " # '"' $ ( =B !)'(&2 ' $# ( #+ &( $# " # '"'/ + * * ' "$& $#*# #( # #( '-#( ( "( $' $& ( %$!- &! $&$# !)'(&2 %%! ( $#$ ( $&$#!)'(&'''$! $#$#)($&' '#,%!$&2 &#'1 ;2 - $*/2)20 . #/ 2)20 ).#('$*/ 22)''2 2#$& 2 "2<:;>/?C/;?=C3;???2 <2 2 2 #/ 2 /22 # / 2# /2# /2 / 22# / 2 # /2 #/ 2"2 "2$2<:;B/;>:/@A;B3@A<@2 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Friday August 17th HT33 Size-specific interaction between isolated gold clusters and graphene devices Ewald Janssens,1 Jeroen Scheerder,1 Shuanglong Liu,2 Vyacheslav S. Zharinov,1 Nicolas Reckinger,3 Jean-Francois Colomer,3 Hai-Ping Cheng,2 Joris Van de Vondel1 1 Laboratory of Solid-State Physics and Magnetism, KU Leuven, Belgium 2 Department of Physics, University of Florida, FL, USA 3 Research Group on Carbon Nanostructures, University of Namur, Belgium Graphene’s two-dimensional nature makes it very susceptible to adparticles: adsorbed atoms or molecules, either individual or clustered. For instance, graphene’s electronic properties have been shown to be susceptible to gas molecule adsorption with a sensitivity down to single molecule detection [1]. Small clusters exhibit distinct electronic and structural properties that vary in a non-scalable way with their size. Theoretical investigations of few-atom metallic clusters as adparticles on graphene suggest that the cluster’s size-dependent properties get carried over in, for instance, graphene’s electronic properties [2]. We investigated the interaction between size-selected Au2,Au3, and Au6 clusters and graphene. Hereto, preformed clusters are deposited on graphene field-effect transistors, an approach which offers a high control over the number of atoms per cluster, the deposition energy, and the deposited density [3]. A major part of the deposited clusters remains on the graphene flake as individual entities. In situ electronic transport measurements on cluster-graphene devices shows size-dependent charge transfer, and hence doping, which is detectable in field-effect measurements (see figure). We also investigated the binding of molecular oxygen to the cluster- graphene system. O2 adsorbs with significant binding energy on the gold clusters. The observed size-dependent effects are in agreement with charge transfers obtained from DFT simulations. Figure 1: Left – sheet conductivity of the graphene device as function of the gate voltage, reflecting size-specific (n-type) doping of soft-landed Au3 and Au6. Right – schematic illustration of the charge transfers following oxygen adsorption on Au3/graphene. This approach provides perspectives for electronic and chemical sensing of metallic clusters down to their atom-by-atom size-specific properties, and exploiting the tunability of clusters for tailoring properties in graphene. [1] F. Schedin, A. K. Geim, S. V. Morozov, E. W. Hill, P. Blake, M. I. Katsnelson and K. S. Novoselov, Nat. Mater. 6, 652 (2007). [2] M. K. Srivastava, Y. Wang, A. F. Kemper, H.-P. Cheng, Phys. Rev. B 85, 165444 (2012). [3] J.E. Scheerder, T. Picot, N. Reckinger, T. Sneyder, V.S. Zharinov, J.F. Colomer, E. Janssens, J. Van de Vondel, Nanoscale 9, 10494 (2017). 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Friday August 17th HT34 + Interaction of swift H2 cluster beam with thin layer graphene foils 1 1 1 1 Min. Li , Jifeng. Han , Guofeng. Qu , Yizhou. Wang 1 Institute of Nuclear Science and Technology, Sichuan University, China + The interaction of H2 micro-clusters, which were generated by the 2.5MV electrostatic accelerator, with thin layer graphene foils and amorphous carbon films were studied by using a high resolution 90° electrostatic analyzer . A large number of proton fragments at zero degree + (along the beam direction) were observed when H2 beam was passing through the single layer + graphene foil, which indicates that the electron of the H2 cluster can be stripped easily even for the single layer graphene foil, and strong Coulomb explosion were happened between the two protons. The energy spectrum of the proton fragments for the 4-layer graphene foil was shown in Figure 1. It is found that the counter number of the low energy peak was much bigger than the high energy peak, which means much more trailing protons were detected than leading protons, in other words, significant wake effect [1,2] were observed for the 4-layer graphene foil. The stopping power of the graphene foils were tested, which is found to be 5 times larger than that of the amorphous carbon films. + + Figure 1: H fragments spectra of 1.8MeV H2 incident 4-layer graphene [1] Pines D, Bohm D. A Collective Description of Electron Interactions: II. Collective vs Individual Particle Aspects of the Interactions[J]. Physical Review, 1952, 85(2):338-353. [2] Vager Z, Gemmell D S, Zabransky B J. Dissociation of fast Heions traversing thin foils[J]. Physical Review A, 1976,14(2):638-641. The project is supported the National Natural Science Foundation of China (11575121). 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Friday August 17th HT35 Low-temperature dissociation of NO molecule in catalytic reduction on size-selected platinum cluster disk bound to silicon substrate H. Yasumatsu1, N. Fukui2 1 Cluster Research Laboratory, Toyota Technological Institute: In 2 East Tokyo Laboratory, Genesis Research Institute, Inc., Japan We have found that O2 molecules are dissociated on a Pt cluster disk bound to a Si substrate, PtN/Si (N=10 - 60), at lower temperature by 150 K [1,2] than on the Pt(111) single-crystal surface [3], resulting in low-temperature CO oxidation. Considering the O2 dissociation is driven by electron transfer to its anti-bonding molecular orbitals, the cluster acts as a highly- efficient electron donor. Indeed, it has been found in our STM observation that electrons are accumulated at the sub-nano interface between PtN and the Si substrate [4,5], O2 adsorbed at which gains electrons. In this presentation, low-temperature dissociation of NO on the cluster disk is reported in connection with catalytic NO reduction, which is indispensable to clean environment in use of combustion engines particularly at high air-to-fuel ratios (lean combustion) having high heat efficiency but high concentrations of nitrogen oxides, NOx. The size-selected cluster disks were prepared by cluster-impact [6] of size-selected cluster ions. The initiation temperature of the NO reduction was measured by means of temperature- programed desorption (TPD) of N2 produced, while its turnover-rate (TOR) by continuous and pulsed gas-flow reactions [7]. It was observed that the NO reduction proceeds on PtN/Si at lower temperature by 70 K than on the Pt(100) single-crystal surface [8]. Its rate- determining step was found to be the NO dissociation, so that it is reliable that the NO dissociation on PtN/Si takes place also at lower temperature. Furthermore, the TOR measurements show high chemical selectivity such that only N2 but neither N2O nor NO2 are produced even with excess O2, mimicking the exhaust gas of the lean combustion. It is concluded that the low-temperature dissociation of NO on PtN/Si derives from the accumulated electrons, considering the NO dissociation is also driven by the electron transfer to the anti-bonding molecular orbitals of NO. The resulting N adsorbates are combined each other to be N2 with high efficiency, but combination between NO and N/O adsorbates are negligible. [1] H. Yasumatsu, Encyclopedia of Interfacial Chemistry: Surface Science and Electrochemistry, ed. Klaus Wandelt (Editor-in-Chief), Elsevier, in press (2018); Book ISBN: 9780128097397. [2] H. Yasumatsu and N. Fukui, J. Phys. Chem. C 119, 11217 (2015). [3] J. Yoshinobu and M. Kawai, J. Chem. Phys. 103, 3220 (1995). [4] H. Yasumatsu, T. Hayakawa and T. Kondow, Chem. Phys. Lett. 487, 279 (2010). [5] H. Yasumatsu, P. Murugan and Y. Kawazoe, Phys. Stat. Solidi B 6, 1193 (2012). [6] H. Yasumatsu and T. Kondow, Rep. Prog. Phys. 66, 1783 (2003). [7] H. Yasumatsu and N. Fukui, Catal. Sci. Technol. 6, 6910 (2016). [8] Y. Ohno et al. Chem. Phys. Lett. 373, 161 (2003). 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Friday August 17th HT36 Reduced sintering of mass-selected Au clusters on SiO2 by alloying with Ti Y. Niu1, P. Schlexer2, B. Sebok3, I. Chorkendorff3, G. Pacchioni2, R. E. Palmer1 1 College of Engineering, Swansea University, U.K. 2 Dipartimento di Scienza dei Materiali, Università di Milano-Bicocca, Italy 3 Department of Physics, SurfCat, Technical University of Denmark, Denmark Au nanoparticles represent the most remarkable example of a size effect in heterogeneous catalysis. However, a major issue hindering the use of Au nanoparticles in technological applications is their rapid sintering. We explore the potential of stabilizing Au nanoclusters on SiO2 by alloying them with a reactive metal, Ti. Mass-selected Au/Ti clusters (400,000 amu) and Au2057 clusters (405,229 amu) were produced with a magnetron sputtering, gas condensation cluster beam source in conjunction with a lateral time-of-flight mass filter, deposited onto planar silica supports and characterised by XPS and LEIS. The sintering dynamics of mass-selected Au and Au/Ti alloy nanoclusters were investigated in real space and real time with atomic resolution aberration-corrected HAADF-STEM imaging, supported by model DFT calculations. A strong anchoring effect was revealed in the case of the Au/Ti clusters, because of a much increased local interaction with the support, by a factor 5x in the theoretical simulations. This interaction strongly inhibits sintering, especially when the clusters are separated by more than ~0.6 nm. Heating the clusters at 100°C for 1hour in a mixture of O2 and CO, to simulate CO oxidation conditions, led to some segregation in the Au/Ti clusters. However, in line with the model computational results, Au atoms were still present on the surface. Thus size-selected nanoalloy Au/Ti clusters deposited on oxide supports appear to be promising candidates for sustainable gold-based nanocatalysis. Figure 1: HAADF-STEM images of dimers of Au2057 and of Au/Ti clusters continuously exposed to electron beam irradiation. While the Au clusters sinter quickly, the Au/Ti clusters show a strong anchoring effect. [1] Y. Niu, P. Schlexer, B. Sebok, I. Chorkendorff, G. Pacchioni and R. Palmer, Nanoscale 10, 2363-2370 (2018). 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Friday August 17th HT37 Research on Electronic Correlation Properties of Low Dimensional Rhodium Qinfang Zhang1, Baolin Wang2 1 School of Materials Science and Engineering, Yancheng Institute of Technology, 224051, Yancheng, PR China 2 School of Physical Science and Technology, Nanjing Normal University, P.O. Box 210023, Nanjing, PR China Rhodium(Rh) is located in the fourth period of the periodic table with d orbitals that are not completely filled, which leads to the strong electronic correlation behavior. In the case of three-dimensional blocks, the strong correlation properties of electrons do not lead to any novel physical properties, which are characterized by the fact that Rh is a paramagnetic metal and possesses the lowest superconducting transition temperature in the simple metal. However, in the two-dimensional, one-dimensional and even zero-dimensional cases, the electronic correlation effect of materials will be greatly enhanced. This is because the dimension reduction process can effectively reduce the energy band width of the material and reduce the shielding behavior of the electrons. The dynamic mean field theory is currently the most advanced method to deal with strongly correlated electronic systems. With the electronic correlation parameters in the materials obtained by the cRPA method, we can predict and verify the electronic structures in the strong correlated systems by first-principles methods. Here we use the dynamic mean-field theory and cRPA method to predict the electronic structure of the simple element in low-dimensional systems. We find that in low dimensional systems, the electronic correlation strength will be significantly greater than that of three-dimensional blocks. This enhancement may result in room temperature magnetism and a high superconducting transition temperature for low-dimensional Rhodium. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Friday August 17th HT38 Silver-copper oxides: are the hopes for superconductivity over? 1 2 2 2 M.Tchaplyguine , Ch. Zhang , T. Andersson , and O. Björneholm 1MAX-lab, Lund University, PO Box 118, 22100 Lund, Sweden 2Department of Physics and Astronomy, Uppsala University, Box 530, 75121 Uppsala, Sweden In comparison to many Cu-oxide based materials fabricated in a search for high temperature superconductivity Ag-Cu oxides have been synthesized relatively late [1,2]. In the fabrication the demand is to create a high and peculiar copper-oxygen coordination which is believed to be a crucial point for superconductivity. Such Cu-oxygen coordination makes it, however, non-trivial to define Cu oxidation state [3], which is not seldom more than one: Cu(II) and/or Cu(III). Another reason for the oxidation state uncertainty is in oxygen deficiency typical for superconducting crystals. This deficiency is believed to create the main current carriers – the holes. Finally, Cu oxidation state is influenced by the other constituent metals, whose valency is also not 100% clear. Soon after chemistry synthesized first Ag-Cu-oxide nanoparticles [1,2] bimetallic oxide nanostructured films were created by reactive co- sputtering of Cu and Ag [4] . However, sputtering has not allowed to produce the composition [5] promising high conductivity – AgCuO2 with higher oxides. The present assumption is that the metals in it are Cu(II+y) and Ag(I+x) states with x and y dependent on the synthesis details [6]. In the oxides possible to fabricate so far the superconducting properties have not been detected, but abnormally high conductivity was [6]. One of the main obstacles to further progress is the inability of chemistry methods to tune the relative abundances of constituent elements in a fine way, while even a small variation of the constituent fractions may destroy the superconductivity or change the superconducting temperature. In the present work we have fabricated Ag-Cu-oxide nanocrystals containing Cu and Ag in high oxidation states actual for high temperature superconductivity. The fabrication method includes reactive co-sputtering of Ag and Cu, plasma-assisted oxidation into metal-oxide molecules, and their aggregation into nanocrystals in the cryogenically cold inert gas. The ability to create different oxidation states in the metal-oxide nanoparticles fabricated by this method has been demonstrated by us [7]. The fabrication approach has also allowed to overcome the usual obstacle: the poor mixability of Cu and Ag [8]. The nanoparticle composition and the oxidation states could be determined due to an experimental arrangement in which photoelectron spectroscopy is applied to free nanoparticles in a beam in vacuum, what allows to avoid any contact of the particles to a substrate or atmosphere. The combination of the employed fabrication and characterization methods has proven to be a powerful approach when fine composition tuning and control at the level of one atomic monolayer are desirable. [1] Gomez-Romero, P.; Tejada-Rosales, E. M.; Palacın, M. R. Angew.Chem. Int. Ed. 1999, 38 (4), 524. [2] Curda, J.; Klein, W.; Liu, H.; Jansen, M. J. Alloys Compd. 2002, 338, 99. [3] P. Steiner, V. Kinsinger, I. Sander, et al. Z. Physik B - Condensed Matter 67 (1987) 497. [4] J.F. Pierson, D. Horwat. Appl. Surf. Scie. 253 (2007) 7522. [5] E. Lund, A. Galeckas, E. V. Monakhov, B. G. Svensson. Thin Solid Films 531 (2013) 185. [6] N. Casañ-Pastor, J. Rius, O.Vallcorba, et al. Dalton Trans. 46 (2017) 1093. [7] Ch.Wright, …, M.-H. Mikkelä, …, O. Björneholm, M. Tchaplyguine, J.Phys.Chem.C 121 (2017) 19414. [8] R.Ferrando, J. Phys.Cond. Matt. 27 (2015) 013003. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China POSTER SESSION A Tuesday Auguest 14th 2018 18:00 – 20:00 Atomic and molecular clusters (A1 – A35) Biotechnological and medical applications-imaging and sensors (A36 – A37) Cluster and nanoparticle assemblies (A38 – A48) Device-oriented topics (A49 – A50) Electron correlation-magnetism and superconductivity (A51 – A54) Supported, embedded and ligated clusters and nanoparticles (A55 – A63) Electronic structure and quantum effects (A64 – A73) Environmental studies (A74 – A75) Atomic and molecular clusters A1 Planar borophenes, cage-like borospherenes, boronanotubes, and their metal-doped heteronanostructures: The double-chain chemistry of boron in boronanostructures Hai-Ru Li and Si-Dian Li* Institute of Molecular Science, Shanxi University, Taiyuan 030006, P. R. China Email: [email protected] Abstract Boron-based nanomaterials have attracted considerable attention in the past decade. We present herein the latest combined experimental and theoretical investigations on cage- q [1-3] like borospherenes Bn (q=n-40, n=36-42) , metal-doped heteroborospherenes Ninę B40 (n=1-6) and their precursor quasi-planar heteroborophene Ni2 ę B14, planar [4] -[5] borophenes , tubular metal-doped molecular rotors B2-Ta@B18 , B3-Ta@B18, and B4- + Ta@B18 , cage-like Ta-doped mononuclear complexes Ta@Bn (n=22-28) with the [6] highest coordination number of CNmax=28 , and perfect dinuclear tubular boron + clusters Ta2@B18 and Ta2@B27 with a Ta-Ta dimer coordinated inside. These nanostructures dominated with the double-chain chemistry of boron (DCCB) exhibit unique structural fluctuations due to the bonding fluctuations originated from the electron deficiency of boron. Boron double chains˄BDCs˅appear to be equivalent to carbon single chains (CSCs) in boronanostructures, exhibiting a clear B/C analogy in chemistry. Boron-based nanostructures possess properties complementary to carbon nanostructures and are expected to have wide applications in catalysis, energy-storage, and electronics materials. Fig.1 Borospherenes and borophenes composed Fig.2 Heteroborospherenes and heteroborophenes of interwoven boron double chains Fig.3 Ta-doped tubular boron complexes with a Ta-Ta dimer coordinated inside References [1] H. J. Zhai, J. Li, S. D. Li, L. S. Wang et al, Nat. Chem., 2014, 6, 727–731. [2] Q. Chen, H. J. Zhai, S. D. Li, L.S. Wang et al, ACS Nano, 2015, 9, 754–760. [3] H. Bai, H. J. Zhai, S. D. Li et al, Angew. Chem. Int. Ed., 2014, 54, 941–945. [4] H. R. Li, S. D. Li et al, Sci. Reports, 2017, 7, 5701. [5] W. L. Li, J. Li. S. D, Li, L.S. Wang et al, Chem. Comm., 2017, 53, 1587-1590. [6] H. R. Li, S. D. Li et al, Nanoscale, 2018, 10, 7451-7456. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Atomic and molecular clusters A2 The electron affinity of Hafnium Atom Rulin Tang, Xiaolin Chen, Xiaoxi Fu, Huan Wang, and Chuangang Ning Department of Physics, Tsinghua University, Beijing 10084, China [email protected] Hafnium atom is the last transition metal element whose electron affinity remains to be determined apart from the radioactive elements. In 1981, Feigerle et al. employed a Cs+ sputter source to produce Hf ions, and investigated its electronic structure via laser photoelectron spectroscopy (LPES). The low signal-to-noise ratio [1] prevented from reaching a definite conclusion regarding the stability of Hf. The lack of a definitive experimental evidence for its stability persists in the latest review for atomic negative ions by Anderson [2], although Nadeau et al. established a lower limit for its EA: t0.1 eV based on accelerator mass spectrometry [3]. Recently, an improved lower limit of EA t0 eV was provided by Davis et al. based on LPES [4]. Using relativistic configuration interaction calculations [5], Pan and Beck predicted that Hf has one bound state 5d26s26p J=5/2 and its EA is 0.114 eV. The EA of Hf remains to be measured. Using a slow electron velocity imaging spectrometer equipped with a cold ion trap, the electron affinity of hafnium atom is measured to be 1436(5) cm1 or 0.1780(6) eV. The cold ion trap employed in the present measurement is found to be crucial for reducing the background noise from the hafnium hydride anions. Figure 1. Mass spectrum from laser ablation on a hafnium metal disk Figure 2. Photoelectron spectra of anions with different mass numbers at the temperature 15 K. The dotted lines indicate the signals of atomic Hf. [1] C. S. Feigerle, et.al. J. Chem. Phys. 74,1580(1981). [2] T. Andersen, Phys. Rep. 394, 157 (2004). [3] M. J. Nadeau et.al., Nucl. Instrum. Methods B 123 521(1997). [4] V. T. Davis et.al., Nucl. Instrum Methods B 241 118(2005). [5] L. Pan and D.R. Beck J. Phys. B: At. Mol. Opt. Phys. 43 (2010) 025002. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Atomic and molecular clusters A3 Multiply charging of superfluid helium nano droplets F. Laimer1, L. Tiefenthaler, S. Albertini1, L. Kranabetter1, P. Scheier1 1 Institute for Ion Physics and Applied Physics/University of Innsbruck, Austria Superfluid helium nano droplets have been widely used as a cryogenic matrix in studies of complexes such as gold clusters[1]. To provide better insight on the nature of superfluid helium nano droplets and their interaction with embedded dopants, the influence of electron impact ionization on pristine superfluid helium nano droplets has been investigated. Positively charged droplets with uniform velocity, produced via supersonic jet expansion and electron impact ionization, are mass selected in an electrostatic sector according to their kinetic energy. The charged droplets are then again subjected to electron bombardment and separated for their mass to charge ratio by a second electrostatic sector. Multiply charging of selected droplets can be observed. Depending on ionization parameters and droplet size the resulting mass to charge distribution of the product droplets varies greatly. These findings spur the development of a mechanism for producing multiple size selected dopant clusters in a single helium nano droplet. Figure 1: Cut drawing of the SNOWBALL setup which was used to measure the mass to charge distributions. [1] M. Goulart et al., Phys. Chem. Chem. Phys 14, 9554-9560 (2018) 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Atomic and molecular clusters A4 From Symmetry Breaking to Unraveling the Origin of the Chirality of Ligated Au13Cu2 Nanoclusters Guocheng Deng, Nanfeng Zheng Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005(China) Chirality is ubiquitous in nature and plays a key role in, for example, enantioselective catalysis, pharmaceutical sciences, optical devices. [1] In the past few decades, people have established numerous chemical means for enantioselective synthesis of chiral molecules for specific applications.[2] A general method, using mixed ligands (here diphosphines and thiolates) is devised to turn an achiral metal cluster, Au13Cu2, into an enantiomeric pair by breaking (lowering) the overall molecular symmetry with the ligands.[3] Using an achiral diphosphine, a + racemic [Au13Cu2-(DPPP)3(SPy)6] was prepared which crystallizes in centrosymmetric space groups. Using chiral diphosphines, enantioselective synthesis of an optically pure, enantiomeric + pair of [Au13Cu2((2r,4r)/(2s,4s)-BDPP)3(SPy)6] was achieved in one pot. Their circular dichroism (CD) spectra give perfect mirror images in the range of 250– 500 nm with maximum anisotropy factors of 1.2h10-3. DFT calculations provided good correlations with the observed CD spectra of the enantiomers and, more importantly, revealed the origin of the chirality. Racemization studies show high stability (no racemization at 70°C) of these chiral nanoclusters, which hold great promise in applications such as asymmetry catalysis. + Figure 1: Overview of [Au13Cu2((2r,4r)-BDPP)3(SPy)6] (left) and [Au13Cu2((2s,4s)- + BDPP)3(SPy)6] (right). Orange Au, green Cu, pink P, yellow S, blue N, gray and pale blue C. All hydrogen atoms and benzene rings are omitted for clarity. [1] T. Mallat, E. Orglmeister, A. Baiker, Chem. Rev. 2007, 107, 4863 – 4890 [2] W. Ma, L. G. Xu, A. F. de Moura, X. L. Wu, H .Kuang, C. L. Xu, N. A. Kotov, Chem. Rev. 2017, 117,8041 – 8093. [3] G. Deng, S. Malola, J. Yan, Y. Han, P. Yuan, C. Zhao, X. Yuan, S. Lin, Z. Tang, B. K. Teo, H. Hkkinen, and N. Zheng, Angew.Chem. Int. Ed. 2018, 57, 3421 – 3425 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Atomic and molecular clusters A5 Investigation on Structural Evolution and Properties of Semiconductor Clusters Doped with metal atoms Hong-Guang Xu*, Sheng-Jie Lu, Bin Yang, Xi-Ling Xu, Wei-Jun Zheng* State Key Laboratory of Molecular Reaction Dynamics, Institute of Chemistry, Chinese Academy of Sciences, China Transition metal (TM)-doped semiconductor clusters have attracted great attention because of their novel structural features and potential technical applications. Gold-doped germanium films can be used for thermopiles in some type of microsensors and for ultralow mass highly sensitive cryogenic phonon sensors because of their high thermoelectric power and hot electron effects. In addition, niobium is an important metal widely used in the alloy industry and it is the first Group V metal to display an s-to-d electron promotion, which may lead to the unique bonding behaviour when it interacts with Si atoms. Niobium silicide-based alloys have a wide range of applications in superconducting digital electronics, and low friction and high temperature corrosion resistant coatings for engines. In this work, in order to get more detailed information regarding the structural and electronic properties of Au-Ge and Nb-Si clusters, we studied AuGe12 and Nb1,2Si12 clusters using anion photoelectron spectroscopy and density functional calculations-based global search. Our results show that the AuGe12 is an Ih symmetric icosahedral structure with the Au atom located at the center. We also found that the global minima of NbSi12 is a D6h symmetric hexagonal prism. The NbSi12 anion is electronically stable due to obeying the 18-electrons rule and having a shell-closed electronic structure The MO analysis and electron localization function (ELF) suggest that there are interactions between 4d orbitals of the Nb atom and the 3s3p hybridized orbitals of Si12. These present findings for novel clusters will provide much valuable information for the development of semiconductor nanotubers and self-assembled functional materials. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Atomic and molecular clusters A6 Accelerating CALYPSO Structure Prediction by Data-driven Learning of Potential Energy Surface 1 1 1 Jian Lv , Yanchao Wang and Yanming Ma 1 State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, China. Ab initio structure prediction methods have been nowadays widely used as powerful tools for structure search and material discovery. However, they are generally restricted to small systems owing to the heavy computational cost of underlying density functional theory (DFT) calculations on structure optimizations. In this work, by combining state-of-art machine learning (ML) potential with our in-house developed CALYPSO structure prediction method,[1,2] we developed two acceleration schemes for structure prediction toward large systems, in which ML potential is pre-constructed to fully replace DFT calculations or trained in an on-the-fly manner from scratch during the structure searches.[3] The developed schemes have been applied to medium- and large-sized boron clusters, both of which are challenging cases for either construction of ML potentials or extensive structure searches. Experimental structures of B36 and B40 clusters can be readily reproduced, and the putative global minimum structure for B84 cluster is proposed, where the computational cost is substantially reduced by~1 - 2 orders of magnitude if compared with full DFT-based structure searches. Our results demonstrate a viable route for structure prediction toward large systems via the combination of state-of-art structure prediction methods and ML techniques. [1] Y. Wang, J. Lv, L.Zhu, and Y. Ma, Phys. Rev. B, 82, 094116 (2010). [2] Y. Wang, J. Lv, L.Zhu, and Y. Ma, Comput. Phys. Commun. 183, 2063 (2012). [3] Q. Tong, J. Lv, and Y. Ma, Fara. Discuss. 10.1039/C8FD00055G (2018). 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Atomic and molecular clusters A7 Magnetic properties of ConRhm alloy clusters Johan van der Tol1,Yejun Li2,MeiyeJia1, Peter Lievens1 and Ewald Janssens1 1 Laboratory of Solid State Physics and Magnetism, KU Leuven, Belgium 2 Hunan Key Laboratory of Super Microstructure and Ultrafast Process, School of Physics and Electronics, Central South University, Changsha, P. R. China The study of magnetism in isolated small atomic clusters connects the magnetic behaviour of single atoms to that of larger nanoparticles. While clusters share the discrete electronic structure with atoms, their magnetic behaviour is altered because they have (1) a geometric structure and (2) an internal temperature. High mass resolution Stern–Gerlach deflection experiments on small clusters are of great interest to address fundamental questions about composition, temperature and magnetism in confined systems. It is, for instance found that the magnetic moments per atom of small cobalt clusters are enhanced compared to the bulk and to nanoparticles [1], which is related to the reduced coordination number [2]. In bulk it has been shown that alloying cobalt with a nonmagnetic 4d metal like rhodium can induce local magnetic moments on the rhodium atoms [3]. Contrary, XMCD measurements on cationic cobalt clusters have shown that alloying with rhodium results in enhanced orbital magnetic moments at the cobalt sites [4]. Measuring the total magnetic moment for neutral clusters with Stern-Gerlach experiments provides complementary information about the total magnetic moments. Our recently developed magnetic deflection set-up for clusters uses a position sensitive detector to accurately and simultaneously measure both the spatial cluster deflection profile and the cluster mass, which is ideal for the study of alloy clusters, as an example ConCrm is shown in Figure 1. In this contribution, the magnetic deflection of ConRhm (n=8-60, m=0-4) clusters will be presented. We found significant enhancements of the magnetic moments of cobalt clusters by alloying them with rhodium. Figure 1: Example of the combination of mass and position sensitivity in our set-up, for ConCrm clusters. A lighter color corresponds to more particles. [1] I.M.L. Billas et al., “Magnetism from the Atom to the Bulk in Iron, Cobalt, and Nickel Clusters”, Science, vol. 265, issue 5179, pp. 1682-1684, 1994 [2] H. Haberland, Clusters of Atoms and Molecules, Springer Berlin Heidelberg, Berlin, Heidelberg, 1994, vol. 52, p. 422. [3] G. Harp et al., ”Induced Rh magnetic moments in Fe-Rh and Co-Rh alloys using x-ray magnetic circular dichroism”, Phys. Rev. B: Condens. Matter Mater. Phys., vol. 51, issue 17, pp12037–12040, 1995 + + [4] D. Dieleman et al, “Orbit and spin resolved magnetic properties of size selected ConRh and ConAu nanoalloy clusters”, Phys. Chem. Chem. Phys., vol. 17, issue 42, 28372-28378, 2015 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Atomic and molecular clusters A8 High resolution photoelectron imaging of boron clusters (B11‾ and B12‾) and transition- metal doped boron cluster (IrB3‾) J. Czekner1, L. F. Cheung1, L. S. Wang1 1 Department of Chemistry/Brown University, USA Anion photoelectron spectroscopy is a powerful tool to probe the electronic and vibrational structure of neutral molecules. We have recently developed a high resolution photoelectron imaging (PEI) apparatus that allows vibrational structures of size-selected clusters to be resolved with a few cm-1 resolution [1]. Here we present our recent high- resolution PEI studies on size-selected boron and doped-boron clusters. We have measured vibrationally-resolved PE spectra of B11‾ and B12‾ [2]. In addition to obtaining accurate electron affinities for B11 and B12, we observed several low frequency vibrational modes for the two neutral clusters, providing further spectroscopic evidence of the planar structures for both the anion and neutral ground states of B11 and B12 [3]. We will also present a high-resolution PEI study of a doped-boron cluster, IrB3‾, revealing two co-existing and nearly degenerate isomers. One is a quasi-planar η2-complex and the second is a tetrahedral η3-complex. The η2-anion is slightly more stable than the η3-anion, but the neutral η3-complex is overwhelmingly more stable. Bonding analyses reveal the stability of the η3-complex is due to the double aromaticity 2 of the B3 ring, which is disrupted in the η -complex. This IrB3‾ cluster represents the first example of a doubly aromatic B3 ligand coordinated to a transition metal. [1] Leon, I.; Yang, Z.; Liu, H. T.; Wang, L. S. The design and construction of a high-resolution velocity- map imaging apparatus for photoelectron spectroscopy studies of size-selcted clusters. Rev. Sci. Instrum. 2014, 85, 083106. [2] Czekner, J.; Cheung, L. F.; Wang, L. S. Probing the structures of neutral B11 and B12 using high resolution photoelectron imaging of B11‾ and B12‾. J. Chem. Phys. C 2016, 121, 10752-10759. [3] Zhai, H. J.; Kiran, B.; Li, J.; Wang, L. S. Hydrocarbon analogues of boron clusters – planarity, aromaticity, and antiaromaticity. Nat. Mater. 2003, 2, 827-833. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Atomic and molecular clusters A9 Catalysis and Co-Crystallization of Protected Atomically Precise Coinage-Metal Clusters J. Z. Yan1,N.F.Zheng1 1 Collaborative Innovation Center of Chemistry for Energy Materials, State Key Laboratory for Physical Chemistry of Solid Surfaces, and Department of Chemistry, Xiamen University, Xiamen 361005, China A comprehensive understanding of factors driving nanoparticle/nanocluster stabilities and chemical bonding and reactions at their nanostructured surface, analogies between these disciplines is of great significance to rationally design multiple functional properties and thus applications purposefully[1], such as catalysis, medicine, energy conversion and optoelectronics, etc. However, the non-molecular nature of conventional nanoparticles makes it extremely challenging to understand the molecular mechanism behind many of their unique electronic, surface properties, and related collective performance. In this presentation, we will present our current efforts toward how to steer surface reactivity, catalytic performance and self-assembly of molecular nanoclusters from the viewpoint of ligand coordination chemistry[2],aswellasthe formation mechanism of discrete nanometer sizes. Specifically, it will cover the following topics: (1) Thiolated atomically precise, superatomic silver nanoparticle-catalyzed reaction of cycloisomerization of alkynyl amines; (2) Programmed assembly of atomically precise metal nanoparticles driven by magic atomic and electronic shells. [1] Liu, P. X.; Qin, R. X.; Fu, G.; Zheng, N. F. Surface Coordination Chemistry of Metal Nanomaterials[J]. J. Am. Chem. Soc., 2017, 139(6): 2122-2131. [2] Yan, J. Z.; Zhang, J.; Chen, X. M.; Malola, S.; Zhou, B.; Selenius, E.; Zhang, X. M.; Yuan, P.; Deng, G. C.; Liu, K. L.; Su, H. F.; Teo, B. K.; Häkkinen, H.; Zheng, L. S.; Zheng, N. F. Thiol-Stabilized Atomically Precise, Superatomic Silver Nanoparticles for Catalyzing Cycloisomerization of Alkynyl Amines[J]. Natl. Sci. Rev., 2018, nwy034: https://doi.org/10.1093/nsr/nwy1034. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Atomic and molecular clusters A10 Formation and structural growth of 2D layer of hafenen on Ir(111) surface and high stability of free-standing Hf clusters Kumneger Tadele 1, 2, Qinfang Zhang1 1 Material Science and Engineering, Yancheng Institute of Technology, China 2 Applied Physics, College of Natural Sciences, Adama Science and Technology University, Ethiopia We have investigated the structures and stability of 2D Hf clusters on Ir(111) surface as the initial stage of hafenen growth using first principles density functional theory (DFT) with the generalized gradient approximation. The study starts with a thorough investigation of adsorption of Hf adatom on the surface of Ir(111). In general, hexagonal close-packed (hcp) hollow is found to be energetically favorable site for the adsorbate, irrespective of number of adsorbates. It is also revealed that the Ir supported 2D Hf clusters of N hexagonal rings prefer a nearly flat honeycomb structure, with exception of N = 1 for which a distorted triangle-like structure is found to be more stable. Neither adsorbed Hf adatom/s nor 2D hafnene layer on Ir(111) surface, unlike to that of free-standing hafenen layer, exhibit magnetic property mainly due to strong hybridization with the Ir(111) surface. We have also performed DFT based simulation study of small size free standing clusters. A thorough investigation has been done to identify the most stable structures of free standing HfN (N ≤ 24) clusters. Formation energy is found to decrease as the cluster size increases, while magnetization is found to show certain fluctuation. The present calculation is supposed to deliver a solid theoretical ground for interpretation and discussion of experimental features of various physical properties and structural growth of hafenen on the surface of transition metals. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Atomic and molecular clusters A11 Photo fragmentation of charged Cs clusters L. Kranabetter, M. Kuhn, P. Martini, J. Postler, F. Laimer, M. Ončák, M. Beyer, P.Scheier Institut für Ionenphysik und Angewandte Physik, University of Innsbruck, 6020 Innsbruck, Austria Helium nano droplets (HNDs) have unique properties that facilitate the growth of clusters and nanoparticles [1, 2, 3]. The ClusTof experiment uses these properties to produce cold cluster ions to analyze them via a high-resolution reflectron time of flight mass spectrometer (TOF MS). + To investigate the micro solvation with He the beam of HemCsn ions is overlapped with a tunable laser light source (EKSPLA NT240-SH-K1). This Q-switched optical parametric oscillator light source generates laser pulses synchronized to specific extraction pulses of the TOF MS. The relative ion yield depletion between the irradiated and non-irradiated pulses of the TOF MS is recorded for wavelengths from 210 nm to 1300 nm for every mass in the spectrum. A relative depletion of the ion yield indicates that the laser is in resonance with an absorption line of the specific ion in the mass spectrum. The figure below shows the relative yield depletion + + of Cs2 and Cs3 versus the laser wavelength. The experimental results are complimented by theoretical calculations to assign electronically excited states to the measured absorption features. + + Figure 1: The relative absorption of Cs2 and Cs3 versus laser wavelength. Acknowledgments: This work was supported by the FWF (Project numbers P26635, P31149 and W1259), and the European Commission (ELEVATE, Horizon 2020 research and innovation program under grant agreement No. 692335) [1] M.Farnik and J.P.Toennies; JCP 122 (2005) 014307; doi: 10.1063/1.1815272 [2] V.Mozhayskiy et al; JCP 127 (2007) 094701; doi: 10.1063/1.2759927 [3] A.W. Hauser et al; PCCP 17 (2015) 01805; doi: 10.1039/C5CP01110H 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Atomic and molecular clusters A12 Study on the Properties of Simple Organic/Inorganic Perovskite Small Molecules Meng-Meng Wang1, Yi-Ming Chen1, Xun-Lei Ding1* 1 Department of Mathematics and Physics, North China Electric Power University, China *[email protected] In recent years, due to its unique structure, organic-inorganic hybrid materials have obtained very wide application prospects in the field of photoelectric functional materials[1-3]. To investigate the interaction between several organic units and inorganic units between + + ABX3(A = HC(NH2) 2 (FA), CH3NH3 (MA), CHNH2OH (JA), B = Pb or Sn, X = F, Cl, Br, I),Our calculations are based on density functional theory (DFT) with the Gaussian 09 program.At the level of the hybrid functional B3LYP/Def2-TZVP basis sets, the clusters structure have been searched globally by using a genetic algorithm-based program, and the most stable configuration of the adsorption of several perovskite clusters has been obtained. We have studied the stable structures with the lowest energy, calculated properties such as binding energy (Eb) and molecular electrostatic potential (MEP) and analyzed the interactions between atoms. The results show that with the increase of the radius of the halogen atoms, the binding energy becomes smaller and the less stable. The binding energy will become larger when considering the diffusion function, and it increases between 0.29 to 0.58 eV. When the halogen element was selected as F, Cl, Br, and I, the binding energy decreased in turn, and I element was the most stable compared to other configurations. For example,3 the binding energy of JASnI3 is 2.60 eV nevertheless the binding energy of MAPbF3 is 6.39 eV. With the solvation effect was added, the energy of the ion systems (A+ and BX -) was significantly reduced, while 3 the energy reductions of neutral systems (A, BX3, and ABX3) were not large, resulting in a decrease in both ionization potentials (IPs) and electron affinities (EAs), thus the dissociation + - channel tends to be the ionization channel A ...BX3 . Keywords: clusters, organic/inorganic perovskite, DFT Acknowledgements: This work was financially supported by the National Natural Science Fundation of China (91545122), and the Fundamental Research Funds for the Central Universities (JB2015RCY03). Figure 1: Molecular electrostatic potential (MEP), iso=0.001.The color scale threshold in the surface electrostatic potential map for all molecules is -0.018-0.016. References: [1] Baishu Zheng, Bo Hou, Zhaoxu Wang. Computational and Theoretical Chemistry. 2013, 1017, 153. [2] Wells, H. L. Z. Anorg. Chem. 1893, 3, 195. [3] Kojima, A.; Teshima, K.; Shirai, Y.; Miyasaka, T. J. Am.Chem. Soc. 2009, 131, 6050. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Atomic and molecular clusters A13 Compositions and structures of palladium oxide cluster cations studied by ion mobility mass spectrometry M. A. Latif 1, Jenna Wu1, Motoyoshi Nakano1, 2, Keijiro Ohshimo1, Fuminori Misaizu1 1 Department of Chemistry, Tohoku University, Japan 2 Institute for Excellence in Higher Education, Tohoku University, Japan [email protected] The well-known catalytic activity of palladium is CO combustion in the automotive system [1-2]. The function and activity of an oxidation catalyst are often governed by its size, morphology, and structure. In addition, the chemical nature of catalyst surface may differ in the presence of oxygen from its bare state. Therefore, the oxidation process of Pd surface was extensively studied for the model catalyst system [3]. It is also important to understand the geometrical structures of palladium oxide clusters in the gas phase as a nano-sized model in order to evaluate the catalytic ability in the bulk phase. In the present study, compositions and size dependent structures of palladium oxide cluster cations have been investigated by ion mobility mass spectrometry (IM-MS). The experiments were performed by using a home-made IM-MS vacuum apparatus. + Palladium oxide cluster cations (PdnOm ) were generated by a combination of laser vaporization and reaction with 5% O2/He carrier gas. The time-of-flight (TOF) mass spectrum and arrival time vs. TOF 2D plot were obtained at ion injection energies to the ion-drift cell of 50 and 250 eV. Experimental collision cross sections (Ωexp) were estimated from the arrival time obtained from the 2D plot by applying kinetic theory of ion transport [4]. On the other hand, structures were optimized by B3LYP/LanL2DZ level in Gaussian 09. Theoretical CCSs (Ωcalc) for the optimized structures were calculated by MOBCAL program [5]. By comparison between Ωexp and Ωcalc, geometrical structures of a specific composition were determined. Stable compositions were determined from the TOF mass spectra shown in Fig. 1. At lower injection energy (50 eV) a variety of cluster cations including + oxygen-deficient to oxygen-rich species, e.g., PdO0-2 , + + + + Pd2O0-4 , Pd3O1-6 ,Pd4O2-8 ,Pd5O3-8 , and + Pd6O3-7 ,were observed (Fig. 1a). Whereas, at higher injection energy (250 eV), comparatively smaller size, and especially, pure metal clusters were preferentially + + + + observed such as PdO , Pd2O0-1 , Pd3O0-1 , Pd4O0-2 , + + Pd5O0-3 , and Pd6O0-3 (Fig. 1b). It reveals that these are the most stable compositions among palladium oxides. At high injection energy, due to collision- + induced dissociation of PdnOm , oxygen-rich clusters were preferentially dissociated to a variety of stable metal and oxygen-deficient cluster species. Detailed structural discussions of the targeted compositions will be shown in the poster presentation. + Figure 1. Mass spectra of PdnOm clusters [1]L. Croft, Nat. Chem. 2, 1009 (2010). [2]H. S. Gandhi et al., J. Catal. 216, 433 (2003). [3]D. H. Parker et al., J. Vac. Sci. Technol., A 8, 2585 (1990). [4]E. A. Mason and E. W. McDaniel, “Transport Properties of Ions in Gases”, John Wiley, New York, 1988. [5]M. F. Mesleh et al., J. Phys. Chem. 100, 16082 (1996). 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Atomic and molecular clusters A14 Ultimate manipulation of magnetic moments in the golden pyramid Au20 with a single 3d impurity N. T. Mai1, N. M. Tam2, H. T. Pham3, N. T. Cuong4, N. T. Tung1 1 Institute of Materials Science and Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Vietnam 2 Faculty of Applied Sciences, Ton Duc Thang University, Vietnam 3 Department of Chemistry, KU Leuven, Belgium 4 Center for Computational Science, Hanoi National University of Education, Vietnam Email: [email protected] Nano-cluster systems that are electronically stable and highly magnetic have been of intense research interest due to their potential as magnetic superatoms [1]. In this study, we consider an intriguing case of the unique golden pyramid doped with a single 3d impurity, Au19M clusters (M = Sc, Ti, V, Cr, Mn, Fe, Co, and Ni), by means of density functional theory calculations. The ground-state structure of doped species is a competition between two geometrical motifs: the endohedrally-doped cage and the exohedrally-doped tetrahedron. Analysis on cluster electronic structures shows that the hybridization between localized and delocalized electronic states governs the stability and magnetic properties of Au19M clusters [2]. Not only the interaction between the magnetic impurity and valence electrons of the Au host but also the itinerant behavior of the impurity valence states have been taken into account to understand the magnetic behavior of studied clusters. Figure 1: The evolution of total magnetic moments (TMM, in μB) of ground-state Au19M clusters and corresponding electronic configuration (red means itinerant electrons) of the dopant. [1] J. U. Reveles et al., Nature Chem. 2009, 1, 310. [2] N. M. Tam et al., Sci. Rep. 2017, 7, 16086. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Atomic and molecular clusters A15 Orbitals of the ionic clusters of hydrated sodium and hydrated fluorine Pengju Wang1, Ruili Shi1, Yan Su*1, Jijun Zhao*1 1Department of Physics, Dalian University of Technology, Dalian 116024, China Alkali metal ion and halogen ion show great difference on hydration. Sodium ion and fluorine ion are chosen to be presenting alkali metal and halogen in this paper, respectively. Sodium ion makes the HOMO orbitals in hydrated sodium ion clusters are lower than vacuum levels, while the vacuum in pure water clusters and hydrated fluorine ion the vacuum levels locate between HOMO and LUMO levels. Meanwhile, the HOMO-LUMO gaps of pure water clusters are lower than that of hydrated sodium ion clusters but higher than that of hydrated fluorine ion clusters. The natural bond orbitals show that the interaction of hydrogen bonds between fluorine ions and hydrogen atoms are much stronger than the hydrogen bonds between water molecules and the interaction caused by sodium ions. Moreover, the wiberg bond order give the effect of electron locating in the two bonds of hydrogen bonds. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Atomic and molecular clusters A16 Planar Doped Boron Clusters B19X (X=Si, C, Al) Q. L. Lu School of Physics and Material Science, Anhui University, Hefei 230601, Anhui, P. R. China E-mail: [email protected] − [1] Boron clusters (Bn ) possess planar or quasi-planar structures up to n=36, 37, 38 . Study on the structures and properties of doped planar boron clusters are essential for doped-borophenes with different vacancy patterns and densities. Neutral B20 clusters is double-ring tubular like structure [2]. An optimization strategy combining global semi-empirical quantum mechanical search and all-electron density functional theory was adopted to determine the lowest energy [3] structure of B19X (X=Si, C, Al) clusters . B19Si and B19Al are almost perfect planar. However, B19C possess a quasi-planar bowl shape. The X atoms occupied a peripheral position due to the difference of atomic size and cohesive energy between X and boron atoms. While the 2 planarization of B19X cluster is attributed to s-p hybridization. B19Si B19C B19Al Figure 1 Structures of B19Si, B19C and B19Al clusters. [1]Q. Chen, W. J. Tian, L.Y. Feng, H. G. Lu, Y. W. Mu, H. J. Zhai, S. D. Li and L.S.Wang, Nanoscale, 2017, 9, 4550–4557. [2]B. Kiran, S. Bulusu, H. J. Zhai, S. Yoo, X. C. Zeng and L. S. Wang, Proc. Natl. Acad. Sci. U. S. A., 2005, 102, 961–964. [3]Q. L. Lu, Q. Q. Luo, Y. D. Li, S. G. Huang, Phys. Chem. Chem. Phys. 2017, 19, 28434-28438. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Atomic and molecular clusters A17 – Structures and Electronic Properties of Cun (n = 1-20) Clusters: a Combined Ab Initio and Photospectroscopic Study Qiuying Du 1, Xue Wu1, Sung Jin Park1, Jijun Zhao1*, Lei Ma2*, Bernd von Issendorff3 1 Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Ministry of Education), Dalian University of Technology, Dalian 116024, China 2 Tianjin International Center of Nanoparticles and Nanosystems, Tianjin University,92 Weijin Road, Nankai District, Tianjin 300072, China 3 Physikalisches Institut, Universität Freiburg, Stefan -Meier-Straße 21, 79104 Freiburg, Germany [email protected] Although the copper clusters have been investigated for over three decades, the knowledge on the lowest-energy configuration and electronic structures are still rather disputed since the description is largely depended upon the theoretical approach. We carried out a combined study of thirteen DFT functionals, two ECP basis and experimental photoelectron spectra (PES) on – anionic Cun (n = 1-20) clusters. The low-energy isomers of anionic clusters have been explored using our extensive, unbiased comprehensive genetic algorithm (CGA) search combined with density-functional theory (DFT). The experimental photoelectron spectra of small-size (n = 1- 10) anionic clusters was used as benchmark to evaluate different theoretical methods, the HSE06 functional with SDD basis show the excellent performance in describing the geometry structure and the electronic property of clusters. Further, applying this method to large-size clusters, the excellent agreement is found between theory and experiment. – Figure 1: Lowest-energy structures of Cun (n = 3-20) clusters. The cluster symmetries are given in brackets. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Atomic and molecular clusters A18 Stability of Au38(SR)24 Cluster Isomers at High Temperatures Rosalba Juarez Mosqueda1, Sami Malola1, and Hannu Häkkinen1,2 1 Department of Physics and 2Department of Chemistry, Nanoscience Center, University of Jyväskylä, FI-40014 Jyväskylä, Finland Despite the great advances in the synthesis and characterization of atomically precise monolayer-protected metal nanoclusters, our understanding on the dynamical behavior of these ultra-small systems, their decomposition mechanisms, and the energy that separates their structural isomers is still very limited. In this work we use density functional theory to analyze and compare the ground state properties and the molecular dynamics (MD) of two well-known [1] [2] Au38(SCH2CH2Ph)24 cluster isomers . The results reveal that the energy that separates the two structural isomers is of the same order of magnitude as the energy difference between the fcc and hcp phases of bulk gold [3]. Moreover, the analysis of the MD simulations discloses that a possible decomposition mechanism triggered by high temperatures occurs via formation and detachment of Aux(SR)y polymeric chains. These results are valuable to understand stability, isomerism, and the robustness of existing and new monolayer-protected metal clusters [4]. Figure 1: Atomic structure of the studied Au38(SCH2CH2Ph)24 cluster isomers. [1] Qian, H.; Eckenhoff, W. T.; Zhu, Y.; Pintauer, T.; Jin, R. J. Am. Chem. Soc. 2010, 132, 8280–8281. [2] Tian, S.; Li, Y.-Z.; Li, M.-B.; Yuan, J.; Yang, J.; Wu, Z.; Jin, R. Nat. Commun. 2015, 6, 8667-1–6. [3] Wang, C.; Wang, H.; Huang, T.; Xue, X.; Qiu, F.; Jiang, Q. Sci. Rep. 2015, 5, 10213-1–11. [4] Juarez-Mosqueda, R.; Malola, S.; Häkkinen, H. Submitted. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Atomic and molecular clusters A19 + First principles study of protonated water clusters H (H2O)n with n = 217 Ruili Shi1, Yan Su1, Linwei Sai2, Jijun Zhao1* 1 Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Dalian University of Technology, Ministry of Education, China 2 Department of Mathematics and Physics, Hohai University, China *[email protected] As a major chemical constituent on the Earth’s surface, water is crucial adjective to all life. Protonated water clusters widely exist in the atmosphere and aqueous solution, and play a very important role for many chemical and biological reactions. Identifying the energy minima of protonated water clusters is a challenging problem. We have implemented a genetic + algorithm[1] combined with DFT to search the ground state structures of H (H2O)n with n = + 217. Among them, the geometric, energetic, and vibrational properties of the H (H2O)2-9,12 clusters were investigated using density functional theory (DFT) along with a variety of exchange-correlation functionals (GGA with B3LYP, BLYP, PBE0, PBE1W, X3LYP, B97D and M05-2X) as well as high-level CCSD(T) and MP2 method.[2] Using MP2 as benchmarks, the effects of seven exchange-correlation functionals were carefully examined. X3LYP is the best to describe the interaction energies, and PBE0 and M05-2X are also recommended to investigate interaction energies. PBE0 gives the best anharmonic frequencies, followed by PBE1W, B97-D and BLYP methods. PBE1W, B3LYP, B97-D, and X3LYP can yield better geometries. The capability of B97-D to distinguish the relative energies between isomers is the best among all the seven methods, followed by M05-2X and PBE0. + On the other hand, we optimized the isomers of H (H2O)10–17 clusters at B97-D/aug-cc- pVDZ level of theory[3] and compared them with the results of Hodges et al.[4,5] The extra + + proton connects with a H2O molecule to form a H3O ion in all H (H2O)10-17 clusters. The lowest-energy structures adopt a monocage form at n = 10–16 and core-shell structure at n =17 based on the MP2/aug-cc-pVTZ//B97-D/aug-cc-pVDZ+ZPE single-point-energy calculation. Using second-order vibrational perturbation theory, we further calculate the infrared spectra + with anharmonic correction for the ground state structures of H (H2O)10-17 clusters at the PBE0/aug-cc-pVDZ level. The anharmonic correction to the spectra is crucial since it reproduces the experimental results quite well. The extra proton weakens the O–H bond + + strength in the H3O ion since the Wiberg bond order of the O–H bond in the H3O ion is smaller than that in H2O molecules, which causes a red shift of the O–H stretching mode in the + H3O ion. [1] Zhao, J.; Shi, R.; Sai, L. et al. Mol. Simulat. 2016, 42: 809. [2] Shi, R.; Huang, X.; Su, Y. et al. J. Phys. Chem. A 2017, 121: 3117. [3] Shi, R.; Li, K.; Su, Y. et al. J. Chem. Phys. 2018, 148:174305. [4] Hodges, M. and Stone, A. J. Chem. Phys. 1999, 110:6766. [5] Hodges, M. and Wales, D. Chem. Phys. Lett. 2000, 324:279. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Atomic and molecular cluster A20 Intriguing excited states of ruthenium anions Rulin Tang, Chuangang Ning Department of Physics, Tsinghua University, Beijing 10084, China [email protected] Two extra bound excited states of atomic ruthenium anions are observed via the slow electron velocity imaging spectroscopy. The lifetime of the two excited states are estimated to be 92 ms and 20 ms via the ion trap, and their energy levels are 2366.0(23) cm1 and 3385.5(22) 1 4 cm above the ground state Ru F9/2, respectively. The two extra excited states cannot be explained using the previous calculations [1] and our own MR-CI calculations. It still needs high level calculations. In addition, the electron affinity of ruthenium is improved to be 8438.74(16) cm1 or 1.046270(20) eV, and the energy levels of Ru4FJ=7/2, 5/2, 3/2 are measured. Figure 1: Photoelectron spectrum of Ru at the photon energy hQ=15110.61 cm1. Peak a, c, d and e are transitions from two extra excited states of Ru. Peak f is related to the transition 3 5 Ru( F4) m Ru ( F9/2), which is used to measure the electron affinity of Ru. Figure 2: Transitions related to the present measurement. E1 and E2 are two extra excited states of Ru‒ found in the present work. [1] P. L. Norquist, D. R. Beck, R. C. Bilodeau, M. Scheer, R. A. Srawley, and H. K. Haugen, Phys. Rev. A 59, 1896 (1999). 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Atomic and molecular clusters A21 Hydrogen bonding interaction in phosphine-ligated small gold clusters Shipeng Wang, Mitsuhiro Iwasaki, Yukatsu Shichibu, Katsuaki Konishi Graduate School of Environmental Science and Faculty of Environmental Earth Science, Hokkaido University, Sapporo, 060-0810, Japan Considerable interests in ligand-protected metal clusters with defined structures have recently emerged due to their unique molecule-like features. Phosphines have been utilized as suitable ligands for the generation of ultrasmall cluster species, offering a ‘Tiny Goldwork’ library with various geometrical and electronic features [1]. During our recent studies on diphosphine- ligated subnano gold clusters, we have found unusual hydrogen-bond-type Au···H-C interaction in the core+exo type Au6 cluster bearing m-phenylene-bridged diphosphine ligands (PhDP) [2]. The attractive interactions, which were found between the Au moiety and the hydrogen atoms at the 2-position of the m-phenylene bridges, were characterized by short Au-H distances (~2.60 Å), nearly linear arrangement of the Au, H and C atoms (~165°), and considerably downfield-shifted 1H and 13C NMR signals of the interacted C-H units. In this work, we studied Au···H-C interactions in similar gold clusters decorated by aryl- bridged diphosphine ligands. Typically, the core+exo type Au8 cluster carrying PhDP (1) was 2+ synthesized from [Au6(PhDP)4] (2) and its structure was analyzed by means of X-ray crystallography and solution NMR. Interestingly, the crystal structure revealed the existence of two types of Au···H interactions (“I Type” and “V Type”) (Fig. 1). The “I Type” interactions, which were found in two phenylene units bridging the bitetrahedral core and exo atoms, are similar to those observed in 2 in terms of the Au-H distances and Au-H-C angles. On the other hand, the remaining phenylene units, which connect between the core atoms, had different geometries, where two Au atoms are in proximity to the C-H group (“V Type” interactions). The presence of such two different Au···H-C interactions was further evidenced in the solution NMR spectra. The H-2 protons due to the phenylene-bridges of 1 exhibited two signals at 11.3 and 9.5 ppm, former of which was almost similar to that of 2 having only “I Type” interactions. Fig. 1: Crystal structure of Au8 cluster (1). [1] Konishi, K. Struct. Bonding 2014, 49, 161 [2] Bakar, M. A.; Sugiuchi, M.; Iwasaki, M.; Shichibu, Y.; Konishi, K. Nature Commun. 2017, 8, 576 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Atomic and molecular clusters A22 From Boron Clusters to Borophenes, Borospherenes and Metallo-borophenes Teng-Teng Chen1,Wan-LuLi2, Tian Jian1,XinChen2,JunLi2, Lai-Sheng Wang1 1 Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA 2 Department of Chemistry and Key Laboratory of Organic Optoelectronics & Molecular Engineering of Ministry of Education, Tsinghua University, Beijing 100084, China In the last two decades, joint photoelectron spectroscopy (PES) and quantum chemistry calculations have revealed pure boron anion clusters (Bn ) possess planar or quasi-planar up to relatively large sizes [1]. Especially, the discovery of B35 and B36 [2-3] has provided the first experimental evidence for the viability of two-dimensional (2-D) graphene-like boron sheets (borophenes), which have been synthesized by several groups [4-5]. All boron-fullerenes have been observed at B39 and B40 , named as borospherenes [6-7]. Metal-doping can expand the potential range of boron-based nanostructures. Several small transition-metal-doped clusters have been investigated to have wheel-like structures (M©Bn , n810). As the size increases, several half-sandwich-like structures have also been discovered. Drum-like structures have been displayed at CoB16 and MnB16 . Here we report our recent studies of CoB18 and RhB18 to show the unprecedented 2D structures, suggesting the possibility of creating 2D metal-doped borophene (metallo-borophene) structures with tunable optical, electronic and magnetic properties [8]. Figure 1: a | A schematic metallo-borophene layer constructed from planar CoB18 units. b |Aschematic metalloborophene layer constructed from quasi-planar RhB18 units. The yellow frame in each figure indicates the unit structure that is repeated in the two spatial dimensions. [1] Wang, L. S., Int. Rev. Phys. Chem. 2016, 35 (1), 69-142. [2] Li, W. L., et al., J. Am. Chem. Soc. 2014, 136 (35), 12257-12260. [3] Piazza, Z. A., et al., Nat. Commun. 2014, 5, 3113. [4] Mannix, A. J., et al., Science 2015, 350 (6267), 1513-1516. [5] Feng, B., et al., Nat. Chem. 2016, 8 (6), 563. [6] Zhai, H. J., et al., Nat. Chem. 2014, 6 (8), 727. [7] Chen, Q., et al., ACS Nano 2014, 9 (1), 754-760. [8] Li, W. L., et al., Nat. Rev. Chem. 2017, 1 (10), 0071. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Atomic and molecular clusters A23 Density functional study of structural, electronic and optical properties of BnCn(n=1-13) clusters Xiaojie Chen1, Chen Zhang1, Pimo He1, Bin Song1 1 Department of Physics, Zhejiang University, China Boron carbides have attracted much attention due to their super hardness, low density, high- temperature stability, excellent thermoelectric properties and high neutron absorption cross section [1]. The combination of these properties makes them fascinating materials for various applications, such as high temperature semiconductor, wear-resistant parts, neutron radiation absorbance in nuclear reactors, and good electrode materials for batteries and fuel cells [2-4]. Consequently, Boron-carbon nanostructures, including nanoribbons, nanowires and clusters, have been the subject of interest in recent years. However, as one of the boron carbide nanostructures, research in the cluster phase is still lacking. The novel features of bulk boron carbides are also expected to be reflected in finite boron-carbon nanostructures. In this work, we first present systematic studies on the structural and electronic properties of stoichiometric BnCn (n=1-13) clusters by density functional study. To this end, we have carried out extensive investigations of the equilibrium geometry, stability, bonding nature, highest- occupied and lowest-unoccupied molecular orbital (HOMO-LUMO) gap and ionization potential for BnCn (n=1-13) clusters. We have calculated the optical absorption spectra of the lowest energy BnCn (n=2,4,6,8,10,12) clusters by using TDDFT method, and the origin of the electronic excitations of these clusters has been discussed. Our results show that the lowest- energy geometries of BnCn clusters tend to form planar structures (cyclic structures). With the increase of size n (n>7), more and more atoms prefer to reside at the interior of the rings, and the planar lowest-energy isomers structures gradually become bowl structures (nonplanar structures). All the nanoclusters show strong absorption in the ultraviolet region and weak absorption in the visible region. In the visible light region, the strongest oscillator strength has little relation with clusters size n, and we obtain that B8C8 cluster is strongest to absorb visible light with strong peak appearing at 2.73eV. In the ultraviolet light region, B4C4 has biggest oscillator strength with strong peak appearing at 10.63eV. Reference(s) [1] A. K. Suri, C. Subramanian, J. K. Sonber, and T. S. R. C. Murthy, Inte MaterRev.55 (2010) 4. [2] K. M. Reddy, P. Liu, A. Hirata, T. Fujita, and M. W. Chen, Nat Commun. 4 (2013). [3] E. Antolini and E. R. Gonzalez, Solid State Ionics. 180 (2009) 746. [4] S. Song, W. Xu, J. Zheng, L. Luo, M. H. Engelhard, M. E. Bowden et al., Nano Lett. 17 (2017) 1417. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Atomic and molecular clusters A24 Three-body fragmentation dynamics of nitrogen dimers by collisions with heavy ions X.L. Zhu1, X. Q. Hu2, S. Yan1, W. T. Feng1, D. L. Guo1, S. F. Zhang1, Y. Gao1, Y. Wu2, S. Xu3, H. B. Wang1, Z. K. Huang1, D. B. Qian1, D. M. Zhao1, P. Dong1,4, M. Zhang1,4, B. Hai1,4, J. C. Zhang1,4, J. G. Wang2, X. Ma1 1 Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China 2 Institute of Applied Physics and Computational Mathematics, Beijing 100088, China 3 School of Science, Xi’an Jiaotong University, Xi’an 710049, China 4 Graduate University of Chinese Academy of Sciences, 100049, Beijing, China [email protected] Weakly bound systems are good prototypes to study the transition from gas phase isolated atoms or molecular to the condensed phase. During the last decades, the numerous theoretical and experimental work focus on the understanding of dynamics, and potential energy surfaces and geometries. The molecular nitrogen is widely exist in the earth’s and planetary atmosphere. Recently, the nitrogen dimer was proposed to constrain planetary habitability and discriminate against false positives for life [1]. The molecular nitrogen dimer (N2)2 is a good candidate. In the present work, the fragmentation dynamics of nitrogen molecule dimers have been studied by using heavy Ne8+ ions at impact energy of 1.0 MeV based on the reaction microscopy in Lanzhou [2,3]. For its three-body fragmentation, three fragmentation mechanisms have been identified by analyzing Dalitz plot and Newton diagram of the momenta of three fragment ions. First one (a) is one-step concerted fragmentation, in which the covalent bond N-N breaks up simultaneously with the breakup of the van der Waals bond N2-N2. Second (b) is van der Waals- first-covalent-second sequential dissociation: the van der Waals bond breaks down in the first + 2+ step, and a stable (N2) molecular ion is emitted, leaving a rotating metastable (N2) ion behind. 2+ The (N2) ion fragments in a second step after a longer time delay. Third one (c) is asynchronous fragmentation, the van der Waals bond breaks down in the first step, and a stable + 2+ 2+ (N2) molecular ion is emitted, leaving a rotating metastable (N2) ion behind. The (N2) ion + + fragments in a second step after a short time delay. One N fragment with N2 ion have stronger columbic interactions than the other N+ fragment. The measured Newton diagram of three-body fragmentation is shown in Figure 1. ଷା ା ା ା Figure 1. The Newton diagram for three-body fragmentationሺܰଶሻଶ ՜ܰ ܰ ܰଶ Ǥ This work is supported by the National Key R&D Program of China under Grant Nos. 2017YFA0402400 and 2017YFA0402300. [1]Edward W. Schwieterman, Tyler D. Robinson, Victoria S. Meadows et al. APJ 810, 57 (2015). [2]Ma X, Zhang R T, Zhang S F et al. Phys. Rev. A 83, 052707 (2011). [3]X.L. Zhu, S. Yan, W.T. Feng et al. Nucl. Instr. Meth. B. 408, 42-45 (2017). 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Atomic and molecular clusters A25 - Structural and bonding properties of MnxCy clusters: anion photoelectron spectroscopy and density functional calculations Xiling Xu, Bin Yang, Hongguang Xu, Weijun Zheng* Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun, Beijing, 100190 [email protected]; [email protected] Transition-metal carbides possess unique physical and chemical properties. It has been suggested that some early transition-metal carbides exhibited unique and intriguing Pt-like catalytic properties, especially in the reactions involving C-H bond activation. Transition-metal atoms not only can be trapped inside fullerene cages to form endohedral metallofullerenes, but also can be incorporated into a carbon cage thus become a part of the cage. Recently, a series of two-dimensional metal carbides known as MXenes were synthesized using early transition metals and were proposed to be promising electrode materials for Li-ion batteries, non-Li ion batteries, and supercapacitor[1,2]. It has been reported that the late transition metals such as Fe, Co, and Ni or their alloys can catalyze the growth of single-walled carbon nanotubes. We − measured the photoelectron spectra of MnxCy (y=1,2) clusters and studied their structures by density functional calculations to investigate their structural evolution and electronic properties. − The vertical detachment energies of MnxCy (y=1,2) were estimated from their photoelectron spectra. The most stable structures were identified by comparing the results of our calculations with the experimental data. Reference [1] Naguib, M.; Come, J.; Dyatkin, B.; Presser, V.; Taberna, P.-L.; Simon, P.; Barsoum, M. W.; Gogotsi, Y. Electrochem. Commun. 2012, 16: 61. [2] Byeon, A.; Zhao, M. Q.; Ren, C. E.; Halim, J.; Kota, S.; Urbankowski, P.; Anasori, B.; Barsoum, M. W.; Gogotsi, Y. ACS Appl. Mater. Interfaces. 2017, 9: 4296. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Atomic and molecular clusters A26 Theoretical study on the atomic structure of (MoSe2)n Xin Cheng, Wen-Jie Wang, Jian-Tao Che, Xun-Lei Ding* Department of Mathematics and Physics, North China electric power university, China *[email protected] In recent years, MoSe2 is one of the most representative materials of 2D transition metal dichalcogenides, which has good performance in wide applications[1]. Compared with the research of the bulk of MoSe2, (MoSe2)n clusters can get defined molecular model, which can be conducive to understand the complex surface structure and reaction process of MoSe2. DFT calculations were performed using Gaussian 09 program with the hybrid B3LYP and pure PW91 functionals. The structure and properties of (MoSe2)n (n=1-3) were studied systematically. After global optimization, we have obtained the stable structure of (MoSe2)n (n=1-3) clusters (Fig.1). For each of the (MoSe2)n clusters, we use na to represent the most stable structure, nb for the substable structure, and so on. The results show that in each (MoSe2)n the Mo atoms form a Mon core, and Se atoms occupies the position of its edge, bridge and surface, respectively. This is the same thing as (MoS2)n clusters[2]. Compared with molybdenum disulfide clusters, the most stable structure of (MoSe2)n is the same as that of (MoS2)n when n=1 and n=3, and (MoSe2)3 has the same 1T type structure as (MoS2)3. The different is that, the Se-Se bond appears in 2a (the most stable structure of Mo2S4) and 3c. The th structure of 2a also exists in Mo2S4, as the 4 most stable one of Mo2S4, which is high in energy than the ground state by about 0.50 eV and 0.37 eV by B3LYP and PW91, respectively. These may indicate that Se-Se bonds are more likely to appear in (MoSe2)n than S-S bonds (MoS2)n. Moreover, by the calculation of magnetic moment of (MoSe2)n clusters, we can find that, for the most stable structure, only the 1a is magnetic, and both 2a and 3a are non-magnetic. Interestingly, the edge of the bulk molybdenum selenide was found to be magnetic[3]. Keywords: (MoSe2)n, 2D transition metal dichalcogenides, DFT n=1 n=1 S Se Mo Mo 3 1a,C ,3B ,0.00 1a,C2v, B1,0.00 2v 1 n=2 n=2 1 3 5 1 3 3 3 1 3 1 2a,C2v, A1,0.00 2b,C2v, A’’,0.28(0.36) 2c,C2h, Bg,0.38(0.70) 2d,C2v, A1,1.09(0.62) 2a,Cs, A”,0.00(C2v, A2) 2b,C2h, Bu,0.16( Ag,0.37) 2c,C3v, A1,0.45(0.65) 2d,C2v, A1,0.50(0.37) n=3 n=3 1 1 1 1 1 ’ 1 3 ” 1 3a,Cs, A’,0.00 3b,C2v, A1,0.40(0.57) 3c,Cs, A’,0.50(0.56) 3d,C3v, A1,0.74(0.97) 3a,Cs, A ,0.00 3b,C3V, A1,0.75(0.98) 3c,Cs, A ,1.38(1.51) 3d,C1, A,1.39(1.36) Figure 1: B3LYP optimized most stable structures of (MoSe2)n (left) and (MoS2)n (right) Acknowledgements: the National Natural Science Foundation of China (91545122), the Fundamental Research Funds for the Central Universities (JB2015RCY03). [1] H.-Y. He; Z. He; Q. Shen, Journal of Colloid and Interface Science, 2018, 522, 136-143. [2] Y.-Y. Wang; J.-J. Deng; X. Wang; J.-T. Che; X.-L. Ding, Phys. Chem. Chem. Phys., 2018, 20, 6365-6373. [3] B.-R. Xia; D.-Q. Gao; P.-T. Liu; Y.-G. Liu, Phys. Chem. Chem. Phys., 2015, 17, 32505. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Atomic and molecular clusters A27 Structures and Electronic Properties of (Ti, Zr, Hf)mSin (m = 1–2, n = 14–20) Clusters: a Combined ab initio and Experimental Study Xue Wu1, S. Zhou1,M.Chen1,M.Lei2, J. Zhao1, B. von. Issendorff3 1 Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Ministry of Education), Dalian University of Technology, Dalian 116024, China 2 Tianjin International Center of Nanoparticles and Nanosystem, Tianjin University, Tianjin, 300072, China 3 Department of Physics and FMF, University of Freiburg, D- 79104 Freiburg, Germany [email protected] – Titanium-doped silicon clusters anions, TimSin (m=1-2, n=14-20), have been investigated by photoelectron spectroscopy and density functional theory calculations. Low-energy – structures of TimSin clusters are globally searched using genetic algorithm incorporated with DFT calculations. The electronic density of states and VDEs have been simulated by using HSE06/aug-cc-pVDZ calculations and compared to the experimental results. Excellent agreement is found between theory and experiment. In general, for size m+n≤17 clusters prefer cage-like structures, while a fullerene-like-based structures with a few Si atoms evolving into an apical bud on the cage as the structural motif are most favorable for the size of m+n>17. The clusters with cage-like have significantly higher stability than that of fullerene-like-based cluster. The charge population shows that the Ti atom possess negative charges acting as an electron acceptor in each cluster size. Among all those measured sizes.Among all those – – measured sizes, Ti1Si16 and Ti2Si15 show the high stability. Furthermore, we removed an electron from the anionic cluster and discussed the stability of the system with 68 delocalized valence electrons of Ti1Si16 and Ti2Si15 clusters. The FK and dist-FK polyhedron isomers with energy degeneracy are all belong to superatom with closed electronic shell consisting of (1S)2(1P)6(1D)10(1F)14(2S)2(2P)6(1G)18(2D)10, which exhibit relatively higher stability. – Inspired by the high stability of Ti1Si16 cluster and the superatom of the corresponding neutral state, we revisit the doped clusters by Si16 cage encapsulating group-IV metal atoms (M@Si16, M=Ti, Zr and Hf) are computationally investigated by both density functional theory (DFT) and high-level CCSD(T) method. Their low-energy structures are globally searched using a genetic algorithm based on DFT. The ground state structures of neutral and anionic M@Si16 are determined by calculating the vertical and adiabatic detachment energies and comparing them with the experimental data. For neutral Ti@Si16, the Frank-Kasper (FK) deltahedron with Td symmetry and distorted FK isomer with C3v symmetry are nearly degenerate as the ground state and may coexist in laboratory, while the distorted FK isomer is − the most probable structure for Ti@Si16 anion. For neutral and anionic Zr@Si16 and Hf@Si16 clusters, the ground states at finite temperatures up to 300 K are the fullerene-like D4d bitruncated square trapezohedron. These theoretical results establish a more complete picture for the most stable structures of M@Si16 clusters, which possess large gaps and may serve as building blocks for electronic and optoelectronic applications. [1] K. Koyasu, J. Atobe, M. Akutsu, M. Mitsui and A. Nakajima, J. Phys. Chem. A 111, 42 (2007). 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Atomic and molecular clusters A28 Li-decorated B16N16 as potential hydrogen storage material Y. Song, H. S. Chen College of Physics and Electronic Engineering, Northwest Normal University, China Hydrogen has been regarded as the most promising candidate to solve the globe’s energy problems because of its nonpolluting and highest heating value per mass[1]. An ideal system for hydrogen storage should be operate under room temperature with high recycling capacity as well as applicable uptake and release kinetic. Searching for ideal hydrogen storage material have been become a research hotspot in the past three decades[2-3]. In this work, we investigate the hydrogen storage properties of Li-decorated B16N16 clusters employing the density functional theory calculations. The study shows that the Li atoms prefer to locate in pairs at two adjacent B-N bridges sharing the same B atom in the B2N2 squares. The binding energy per Li is about -1.19 eV. Li atom donates part of electrons from 2s orbital to the virtual 2p orbital of B16N16 and forms positive ion, and the hydrogen molecules are thus moderately polarized and adsorbed on the Li atoms. Figure 1 presents the NBO charge of B16N16Li2. It shows that Li atom carries large positive charge of 0.70e. Each Li atom can adsorb one to two H2 molecules. The adsorption energy per H2 is 0.21-0.32 eV with the van der Waals correction of Grimme[4], which is ideal for hydrogen storage materials to operate under ambient temperature. The gravimetric hydrogen density can reach 9.08 wt. % when B16N16Li12 adsorbs 24 H2, which is larger than the goal value of 5.5 wt. % given by the U.S. Department of energy for 2020. The corresponding structure is shown in Figure 2. The present calculation result can give directions for exploring reversible hydrogen storage materials with high recycling storage capacity at ambient conditions. Figure 1: The NBO charges on B16N16Li2. Figure 2: The structure of The blue, pink and yellow balls represent B16N16Li12 cluster adsorbed the B, N and Li atoms respectively. by 24 H2. [1] W. Lubitz and W. Tumas, Chem. Rev. 107, 3900 (2007). [2] M. P. Suh, H. J. Park, T. K. Prasad et al., Chem. Rev. 112,783 (2012). [3] X. L. Jin, P. T. Qi, H. H. Yang, Y. Zhang, J. Y. Li and H. S. Chen, J. Chem. Phys. 145,164301 (2016). [4] S. Grimme, J. Comput. Chem. 27, 1787 (2006). 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Atomic and molecular clusters A29 - Structural and Electronic Properties of CrnSi15-n (n=1-3) Clusters: Photoelectron Spectroscopy and ab initio Calculations Bin Yang1,2, Xiling Xu1,2, Hongguang Xu1,2, Weijun Zheng1,2 1 Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Molecular Reaction Dynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China 2 University of Chinese Academy of Sciences, Beijing 100049, China [email protected] - CrnSi15-n (n=1-3) clusters were investigated by using anion photoelectron spectroscopy - combined with density functional theory calculations. The CrSi14 is a pentagonal prism with four - Si atoms capping on four of five side faces symmetrically. The most stable structure of Cr2Si13 can be characterized as one Si atom capped on the hexagonal prism Cr2Si12, and a distorted hexagonal anti- - prism isomer coexist in the experimental results. For Cr3Si12 cluster, three Cr atoms form an axle and are surrounded by Si12 cage. The simulated spectra of low-lying isomers based on the theoretical calculations can excellently reproduce the peaks and intensities of the experimental - - - spectra. The magnetic moments of CrSi14 , Cr2Si13 and Cr3Si12 are 1 μB, 3 μB and 7 μB - respectively. It is also worth mentioning that Cr3Si12 cluster has strong aromaticity. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Atomic and molecular clusters A30 Encapsulation storage of H2 molecules in a cagelike (MgO)12 cluster Yan Zhang College of Physics and Electronic Engineering, Northwest Normal University, China Cluster-based materials are candidate materials for solid-state hydrogen storage owing to their special geometric and electronic structures. The cluster with a cagelike structure could enable the storage of H2 molecules via two methods, surface adsorption and encapsulation storage. Surface adsorption involves the interaction between H2 molecules and host clusters. Encapsulation storage involves the storage of H2 in the interior space of the cagelike structure. The latter is essential for practical applications of cagelike clusters because the interior space is retained when they are assembled into solid-state materials, although many surface adsorption sites are occupied. A cagelike (MgO)12 cluster presents a good stability and many larger MgO cluster isomers grow upon this cagelike structure [1,2]. It has been proposed to assemble porous materials with large surface-to-volume ratios [3,4]. Here, we report an investigation on surface adsorption and encapsulation storage of H2 molecules in the cagelike (MgO)12 cluster based on a dispersion-corrected density functional theory calculation [5]. The results revealed that the cagelike (MgO)12 cluster surface can adsorb 24 H2 molecules with an average adsorption energy of 0.116 eV/H2, which brings about a gravimetric density of 9.1 wt%. In the interior space of cagelike (MgO)12 cluster, a maximum capacity of six H2 molecules could be stored according to symmetric configurations, as shown in Figure 1. The encapsulated H2 molecules are trapped by stepwise energy barriers of 0.433–2.550 eV, although the storage is an endothermic process. This study will be beneficial for hydrogen storage in cagelike clusters and assembled porous materials. Figure 1: Stable encapsulated (H2)n (n=1-6) molecular clusters in the cagelike (MgO)12 cluster. [1] Y. Zhang, H. S. Chen, Y. H. Yin, and Y. Song, Structures and bonding characters of (MgO)3n (n=2-8) clusters, J. Phys. B: At. Mol. Opt. Phys. 47, 025102 (2014). [2] Y. Zhang, H. S. Chen, B. X. Liu, C. R. Zhang, X. F. Li, and Y. C. Wang, Melting of (MgO)n (n=18, 21, and 24) clusters simulated by molecular dynamics, J. Chem. Phys. 132, 194304 (2010). [3] J. Carrasco, F. Illas, and S. T. Bromley, Ultralow-density nanocage-based metal-oxide polymorphs, Phys. Rev. Lett. 99, 235502 (2007). [4] Y. Zhang and H. S. Chen, Thermal stability of (MgO)12 dimers, Eur. Phys. J. D 66, 25 (2012). [5] Y. Zhang and H. S. Chen, Surface adsorption and encapsulated storage of H2 molecules in a cagelike (MgO)12 cluster, Int. J. Hydrogen Energy (2018), https://doi.org/10.1016/j.ijhydene.2018.07.026 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Atomic and molecular clusters A31 Theoretical Studies on Metal Clusters Y. Dong1, M. Springborg1 1 Physical and Theoretical Chemistry, University of Saarland, Germany Metallic isolated Magnesium clusters are studied by density functional tight binding method combining with global optimization tool genetic algorithms. Various descriptors are used in analysing the results, including stability, shape, and similarity functions, as well as radical distances of the atoms and the orbital energies, all as functions of N. Meanwhile, other electronic properties of the optimized magnesium clusters are also studied, for example, the binding energy, the HOMO-LUMO gaps. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Atomic and molecular clusters A32 Structural evolution and superatoms in molybdenum atom stabilized boron clusters: MoBn (n = 10-24) Yuqing Wang, Xue Wu, Jijun Zhao* Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, Dalian 116024, China Abstract Doping transition metal atom is known as an effective approach to stabilize an atomic cluster and modify its structure and electronic properties. We herein report the effect of molybdenum doping on the structural evolution of medium-sized boron clusters. The lowest-energy structures of MoBn (n = 10, 12, 14, 16, 18, 20, 22, 24) clusters are globally searched using genetic algorithm combined with density functional theory calculations. We found that Mo doping has significantly affected the grow behaviors of Bn clusters, leading to a structural evolution from bowl-like to tubular and finally endohedral cage. The size-dependent binding energy, HOMO- LUMO gap, vertical ionization potential and vertical electron affinity show that MoB12, MoB22 and MoB24 clusters have relatively higher stability and enhanced chemical inertness. More interestingly, the endohedral MoB22 cage is identified as an elegant superatom, which satisfies 18-electron closed shell configuration well. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Atomic and molecular clusters A33 Chirality introduction into gold clusters: structures and optical properties Y. Ogawa, M. Sugiuchi, Y. Shichibu, K. Konishi Graduate School of Environmental Science, Hokkaido University [email protected] Gold clusters have received wide research interests due to their various physicochemical properties arising from gold geometries and/or nuclearities. By using various diphosphine ligands, we have succeeded in syntheses of non-spherical gold clusters with intense absorption [1] bands. In addition, we found that chelating DPPE can highly stabilize a spherical Au13 core and the cluster exhibits unique absorption and photoluminescence properties.[2] We also reported a regioselective introduction of two alkynyl units on the “magic-numbered” Au13 core.[3] In this work, we succeeded in syntheses of chiral diphosphine-protected gold clusters, and evaluated their optical activities. The effect of a cluster-π electronic interaction on chiroptical properties was also examined. Syntheses of gold clusters having chiral diphosphine ligands (DIPAMP, Chiraphos) were performed from the chemical reductions of gold-diphosphine complexes followed by the HCl- induced nuclearity convergence (Scheme 1).[2] The resulting products after purification were characterized by electrospray ionization mass spectrometry and 31P NMR. Geometric structures of enantiomeric gold clusters were determined using single-crystal X-ray structural analysis.[4] Furthermore, their optical activities were revealed from circular dichroism and circularly polarized luminescence measurements. Scheme 1. Synthesis of chiral gold clusters and the ligands used in this work. [1]K.Konishi, Struct. Bonding 204, 161, 95. [2]Y.Shichibu et al., Small 2010, 6, 1216. [3]M.Sugiuchiet al., Chem Commun. 2015, 51, 1351. [4] M.Sugiuchi et al., Angew. Chem. Int Ed. 2018, in press. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Atomic and molecular clusters A34 investigating the solution of Calcium iodide by photoelectron spectroscopy and DFT Zhi-You Wei1,Hong-Guang Xu1,Wei-Jun Zheng1* 1Institut of Chemistry, Chinese Academy of Sciences,China The salts play important roles in biochemistry, marine chemistry, and atmospheric chemistry, as well as in our daily life[1][2]. Dissolution of salts is a fundamental process in chemistry. During the solvation process, the anion and cation of the salt which exists as contact ion pairs (CIPs) can be separated by the solvent molecules to form solvent-separated ion pairs (SSIPs). One interesting question is how many solvent molecules are needed to separate the CIP of a particular salt[3]. In this paper, we present our - recent results on divalent salt iodide calcium CaI2(H2O)n (n=0-8) clusters and their neutrals by combining anion photoelectron spectroscopy and DFT. It is found that the ion pair structures vary when the number of water molecule changes. This research not only enable us to understand the interaction between ions and water, but also give us a basic understanding of the mechanism of salt dissolution. - Figure 1: Photoelectron spectra of CaI2(H2O)n (n=0-8) and the most probable structures of - CaI2(H2O)n (n=0-2) clusters are shown [1] Cserháti, T.; Forgács, E. Int. J. Pharm. 2003, 254, 189−196. [2] Asmar, B. N.; Ergenzinger, P. Hydrol. Process. 2002, 16, 2819−2831. [3] Jungwirth, P. J. Phys. Chem. A. 2000, 104, 145ɝ148. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Atomic and molecular clusters A35 Unique Bonding and Structural Evolution in the Doped Boron Clusters with Alkali/alkaline Earth Metals Zhong-hua (Cui) Institute of Atomic and Molecular Physics, Jilin University, Changchun, China. Doped boron clusters with transition metals have created a series of clusters with novel structures and chemical bonding, such as metal-centered monocyclic rings, metalloborophenes, half-sandwich structures, metal-centered tubular structures and cages.1 The alkali and alkaline earth metals have been used to check whether isolated boron clusters can be considered as promising ligand and building blocks for boron-based materials or not. We present in these works the new aspects of doping boron clusters with alkali and alkaline earth metals. For example, we recently found that the intriguing structural transition of 1D-2D-3D occurred in LinB12 (n=1,2,3), of which structural transition is due to the enhanced electrostatic interactions 2 arising from the charge transfer from Li to boron motifs. The discus-shaped species Be2B8 and - Be2B7 exhibit double aromaticity with 6σ and 6π electrons where the double aromaticity boron rings firmly hold the extremely short Be–Be distance, but there is no Be-Be bond.3 We hope that our current findings will offer useful information for stability, bonding, and structural evolutions of doped boron clusters. Keywords: Boron clusters, High-level calculations, Bonding, Structural evolution [1].Li, W.-L. et al. From planar boron clusters to borophenes and metalloborophenes. Nat. Rev. Chem. 1, 71 (2017). [2].Dong, X. et al. Li 2 B 12 and Li 3 B 12 : Prediction of the Smallest Tubular and Cage-like Boron Structures. Angew. Chemie 130, 4717–4721 (2018). [3].Cui, Z., Yang, W., Zhao, L., Ding, Y. & Frenking, G. Unusually Short Be−Be Distances with and without a Bond in Be 2 F 2 and in the Molecular Discuses Be 2 B 8 and Be 2 B 7 −. Angew. Chemie 128, 7972–7977 (2016). 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Biotechnological and medical applications-imaging and sensors A36 High rate generation of size-controlled Ag/Cu clusters in vacuum and its application in antimicrobial coatings Jinlong Yin, Giuseppe Sanzone, Hailin Sun Teer Coatings Ltd, Miba Coating Group, West-Stone-House, West-Stone, Berry- Hill- Industrial-Estate, Droitwich, Worcestershire, WR9 9AS, United Kingdom In recent years, there has been a growing interest in developing antimicrobial coatings for the applications in medical and food industry. In these environment it is vital to control or rather to limit the growth of microorganism, which can cause serious hygienic and quality control issues. Small amount of copper or silver have been added into various coatings, for example CrN or TiN, to prohibit the bacteria or fungi from growing [1]. However the influence of Ag or Cu particle size on the antimicrobial properties is not very clear, and it has not been widely investigated either. In this poster, we are going to present our planned approach to investigate the correlations between metal particle size and antimicrobial properties. We have developed a Cluster-Beam source [2], which employs magnetron sputtering technology to produce clusters at high throughput. Clusters that are produced by a gas- condensation process in vacuum, have many advantages compared to those prepared via a conventional wet-chemistry route. Inherently these gas phase nanoparticles are very clean and pure, because there is no contamination from ligands. The majority of the nanoparticles produced by magnetron sputtering are electrically charged, and this has made it convenient to employ a Time-of-Flight mass filter to select the particle size [3]. Although the particles produced in magnetron sputtering chamber have a relatively broad size distribution, they will have a very narrow size distribution, typically +/- 10% of diameter, after mass selection. This offers a powerful tool to investigate the influence of particle size on antimicrobial properties. By optimizing the gas dynamic inside the vacuum chamber, we were able to improve the cluster flux by 3 to 5 times. Ultimately, we expect to improve the production rate by a factor of ~ 100. This will raise the possibility of mass-production of such high-purity and size-selected nanoparticles, which in turn will lead to many new and future commercially significant applications. [1] P.J. Kelly, H. Li, P.S. Benson, K.A. Whitehead, J. Verran, R.D. Arnell, I. Iordanova, Surface & Coatings Technology 205 (2010) 1606–1610 [2] Peter R. Ellis, Christopher M. Brown, Peter T. Bishop, Jinlong Yin, Kevin Cooke, William D. Terry, Jian Liu, Feng Yin and Richard E. Palmer, The cluster beam route to model catalysts and beyond, Faraday Discuss., 2016, 188, 39. [3] S. Pratontep, S. J. Carroll, C. Xirouchaki, M. Streun, and R. E. Palmer, Rev. Sci. Instrum. 76 (2005) 045103. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Biotechnological and medical applications-imaging and sensors A37 Nucleic Acid Binding Studies of New Cyanine Dyes V. K. Saarnio1, V. P. Ruokolainen2, K. Salorinne1, T.-R. Tero1, T. M. Lahtinen1, V. S. Marjomäki2 1 Department of Chemistry, Nanoscience Center/University of Jyväskylä, Finland 2 Department of Biological and Environmental Science, Nanoscience Center/University of Jyväskylä, Finland For the fluorescent sensing of nucleic acids, cyanine dyes are great probes.[1] A commercial and widely used dye, SYBR Green, exhibits over a thousand fold increase in fluorescence upon intercalating to DNA.[2] We have developed an alternative synthesis route for these dyes to provide improved probes. Here, we describe new cyanine dyes with added functionalities, present their spectroscopic and binding properties. These dyes will serve as precursors for metal enhanced fluorescence sensing of nucleic acids. The binding to different nucleic acids was studied with fluorescence spectroscopy. The binding constants and binding site size were determined with McGhee von Hippel equation.[3] In vitro experiment with MeS was conducted with Echovirus 1. A longer R-group on a molecule increases the binding affinity but it also leads to faster saturation in binding. The dye with a shorter R (MeS), binds more weakly but produces higher fluorescence with increased concentration with different nucleic acids. The newly synthesized fluorescent probes provide enhanced tools to monitor RNA and DNA. The compounds will be further employed to develop conjugates with metal nanoparticles. Metal enhancement to fluorescence can be expected to yield products with increased sensitivity and more sophisticated uses for DNA/RNA sensing.[4] [1] Karlsson, H. J. et al., Bioorganic Med. Chem. 2004, 12, 2369-2384. [2] Dragan, A. I. et al., J. Fluoresc. 2012, 22, 1189-1199. [3] McGhee, J. D. and von Hippel, P. H. J. Mol. Biol. 1974, 86, 469-489. [4] Dragan, A. I. et al., Anal. Biochem. 2010, 396, 8-12. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Cluster and nanoparticle assemblies A38 Cooperativity at the nanoscale Ani Baghdasaryan1, Elodie Brun2, Giovanni Salassa1, Jerome Lacour2 and Thomas Burgi1 1 Department of Physical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland 2 Department of Organic Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland Molecular recognition events are part of critical biological processes such as recognition of the substrates by enzymes, transmission of cellular signals, recognition of cells and DNA replication [1]. The specific binding of ligand (guest molecule) to the receptor (host molecule) leads to the formation of host-guest noncovalent supramolecular complexes. An important class of interactions in biology involves more than one ligand molecule binding to a receptor. When the binding of one of these molecules alters the affinity of the other molecules for the receptor, the interactions are known to be cooperative or allosteric [2]. Herein, for the first time, the cooperative effect for host-guest supramolecular complexes using Au25 cluster has been observed. The ligand exchange reaction with thiolated 18C6 crown macrocycle (L) leads to the formation of Au25(2-PET)18-2xLx species (0 A B Fig.1. A) In-situ UV-vis studies of ligand exchange and B) MALDI analysis of the separated two fractions (F1 and F2) on SEC column The exchange product can be easily isolated by size exclusion chromatography. Furthermore, NMR titration has been used to determine the possible binding of the chiral amines ((R/S)- 3,3- Dimethyl-2-butylamine) onto the crown cavity by following the shift of the protons in 1H- NMR spectrum. The dissociation constants KD for the interactions have been obtained from Hill’s plot. It has also been shown, that depending on the enantiomer of both, cluster and the amine, the binding affinity can be tuned from millimolar to micromolar. Moreover, depending on the average exchange number (ݔҧ) of the crown moiety on the cluster surface, the Hill’s coefficient (indication of the cooperativity) changes. [1] John Kuriyan, Boyana Konforti, David Wemmer, ‘The molecules of life: physical and chemical principles’, Garland publishing 2008. [2] Christopher A. Hunter and Harry L. Anderson, ‘What is cooperativity?’, Angew. Chem. Int. Ed. 2009, 48, 7488 – 7499. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Cluster and nanoparticle assemblies A39 Au25(SR)18 cluster assembly in multiple dimensions A. Sels1, G. Salassa1, L.-T. Lee2, F. Cousin2, T. Bürgi1 1 Department of Physical Chemistry, University of Geneva, Geneva, Switzerland 2 CEA Saclay, UMR CEA CNRS 12, Lab Leon Brillouin, F-91191 Gif Sur Yvette Designing new generations of superstructures by controlled self-assembly of nanosized objects has great potential in applications such as molecular electronics or sensors.[1] Monolayer protected gold clusters are optimal building blocks due to their well-defined structure, high stability and unique size-dependent characteristic.[2] Formation of superstructures without modification the original clusters structure could however be a challenging task. Ligand exchange reactions are a valuable solution for this problem. It involves the replacement on the Aun(SR)m cluster surface of one of the protecting thiol (ligand) with a new entering ligand SR’. As bridging agent rigid linear aryl dithiols were chosen, replacing two original protecting ligands. This dithiol is expected to create a conducting system, which allows communication between the covalently bonded Au25(SR)18 clusters. Figure 1: Absorption spectra of pure and linked Au25(SBut)18 clusters (left) and schematic representation of the linked clusters (right) Several techniques (e.g. NMR and SAXS) confirmed a successful assembly into dimers, trimers and large networks of linked clusters, separated by a well-defined distance. The absorption spectra of these larger aggregates are drastically different from the original clusters, the former absorbing at lower energies. We ascribe this drastic change of the absorption spectra to the communication between the clusters in the aggregates through the aromatic linker. Additionally, the size of these aggregates could be reduced through the unlinking reaction, resulting in a shift of the absorption band in direction of the original Au25 spectrum. This formation of communicating clusters gives interesting perspectives for the creation of conducting two dimensional arrays. The development of these superstructures and their electrical properties could be an important step towards the use of well-defined metal clusters in molecular electronics. [1] Calard, F., Mol. Syst. Des. Eng., 2017, 2 (2), 133-139 [2] Lahtinen, T., Nanoscale, 2016, 8 (44), 18665-18674 [3] Fernando, A., J. Phys. Chem. C, 2015, 119 (34), 20179-20187 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Cluster and nanoparticle assemblies A40 Flexible gas sensor for hydrogen based on Pd nanoparticle film Bo Xie Institute for Advanced Materials and Hubei Key Laboratory of Pollutant Analysis & Reuse Technology, Hubei Normal University, Huangshi 435002, P. R. China Palladium (Pd) nanoparticle (NP) film for flexible hydrogen sensor has been successfully fabricated on a polyethylene terephthalate (PET) sheet. The Pd NP film, coated on the flexible substrate by performing cluster beam deposition, exhibited discrete nanogranular structure which endow the sensor good flexibility and prominent sensing performance. The attractive advantage of our sensor is that the sensing behavior can be tuned conveniently or even optimized by applying strians to the flexible substrate. The possible influence mechanism of the tensile and compressive strains on H2-sensing performance was attributed to the changes in the percolation network topology and the inter-particle space induced by the strains. In addition, our sensor was subjeted hundreds of bending cycltest and showed good electrical stability and mechanical robustness without significant degradation in H2-sensing ability. The capability of sensing H2 concentrations as low as 24 ppm and a sub-ten seconds response time have been achieved. Due to the excellent flexibility and the prominent sensing performance, the sensor is promising for application in flexible and wearable sensing electronics which may be usable for the Internet of Things. Figure 1 The artist’s view of schematic of the device exposing to H molecules (red) 2 under bent state. Pd NPs are illuminated by the silvery white spheres. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Cluster and nanoparticle assemblies A41 A body-center-cubic Au9 nanocluster Hui Shen, Nanfeng Zheng State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, and Engineering Research Center for Nano- Preparation Technology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China [email protected] Basic polyhedron-based unit clusters are of paramount importance in the family of atomically precise coinage metal nanoclusters as they act as building block of larger ones.[1] Those basic polyhedron-based unit clusters such as tetrahedral M4 [2], icosahedral M13 [3], and face-center- cubic M14 [4]have been fully characterized. To our pity, however, body-center cubic M9 is absent in the class. Shown here is crystal structure and other characterization of an all- phosphine-protected Au9 nanocluster with nearly perfect body-center-cubic structure. The Au9 reported here remains the smallest body-centered cubic nanocluster and thus, together with other polyhedron-based unit clusters, comprises a more complete building block family. Synthesis of such non-rigid-ligand capped Au9 nanocluster offers us opportunities of utilizing body-center-cubic unit nanoclusters as next-generation building block to assembly nanocluster- based materials and puts forward new challenge on explaining controlling factors of nanoclusters formation. Figure 1: Crystallographic structure of body-center-cubic Au9(PPh3)8 nanocluster. All carbon and hydrogen atoms are omitted for clarify. [1]Jin, R.; Zeng, C. J.; Zhou, M.; Chen, Y. Chem. Rev. 2016, 116, 10346; [2]Zeller, E.; Beruda, H.; Schmidbaur, H. Inorg. Chem. 1993, 32, 3203; [3]Y. Shichibu, Y. Kamei and K. Konishi, Chem. Commun., 2012, 48, 7559–7561; [4]Yang, H. Y.; Lei, J.; Wu, B. H.; Wang, Y.; Zhou, M.; Xia, A. D.; Zheng, L. S.; Zheng, N. F. Chem. Commun. 2013, 49, 300. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Cluster and nanoparticle assemblies A42 A close-packed N-doped carbon sphere for advanced lithium-sulfur battery cathode Qian Lu, Yijun Zhong, Wei Zhou, Kaiming Liao, and Zongping Shao School of Energy Science and Engineering, Nanjing Tech University, China [email protected]; [email protected] Lithium-sulfur (Li-S) battery is considered as one of the most promising candidates of next- generation rechargeable battery systems owing to high theoretical capacity, natural abundance, and low cost of sulfur.[1] However, two vital issues still need to be addressed for its practical applications. The first one is the shuttling of high-order polysulfides (Li2Sn, 4İnİ8) that results in short cycling life, significant self-discharge, and decreased Columbic efficiency of the batteries.[2] The second one is the inherent poor electrical conductivity of the sulfur (5×10 -30 S cm-1 at 25 oC) that often leads to unsatisfactory rate capabilities and poor utilization of sulfur.[3] In this work, a close-packed N-doped hollow carbon sphere (CCS) is designed and synthesized as a new type of sulfur host for Li-S battery that shows both high rate performance and cycle stability. Based on a novel dodecylamine (DDA) micelles induced self-assembling, the CCS host with close-packed hollow submicron N-doped carbon yolks structure was served as well-developed electrical conducting networks. A comparison of CCS host with the conventional host of isolated hollow carbon spheres (ICS) was also conducted. The nitrogen doping enhanced the intrinsic conductivity of the carbon materials, while the construction of close-packed structure provided an efficient electrical conducting network. Both helped to improve the rate performance of the electrode. The nitrogen doping also introduced chemical confinement of polysulfides, which benefited the cycle stability. As a result, both rate capability and cycle stability was improved for the novel CCS host. Figure 1: Schematic illustration of the dodecylamine-induced synthesis of close-packed N- doped hollow carbon sphere cathode for Li-S battery. [1] X. Ji, K. T. Lee, and L. F. Nazar, Nat. Mater. 2009, 8, 500. [2] K. Liao, P. Mao, N. Li, M. Han, J. Yi, P. He, Y. Sun, and H. Zhou, J. Mater. Chem. A 2016, 4, 5406. [3] Q. Lu, Y. Zhong, W. Zhou, K. Liao, and Z. Shao, Adv. Mater. Interfaces 2018, 1701659. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Cluster and nanoparticle assemblies A43 Dithiol-Induced Oligomerization of Thiol-Protected Gold Nanoclusters Karolina Sokołowska, Eero Hulkko, Lauri Lehtovaara and Tanja Lahtinen Department of Chemistry, Nanoscience Center, University of Jyväskylä P.O.Box, 40014 Jyväskylä, Finland [email protected] We present synthesis, separation and detailed analysis of possible reaction mechanism to produce dimers and larger oligomers of thiol-protected nanoclusters.[1,2] Nanocluster oligomers were synthesized using monodisperse para-mercaptobenzoic acid (p-MBA) protected gold nanoclusters with a nominal composition of Au~250(p-MBA)n to minimize ensemble effects on size, shape, and surface structure. The generality of the synthesis is proven by performing the ligand exchange on the nanocluster with five different dithiol linkers: 5,5´- bis(mercaptomethyl)-2,2´-bypyridine (BMM-BPy), 4,4´-thiobisbenzenethiol (TBBT), benzene- 1,4-dithiol (BDT), 1,4-benzenedimethanethiol (BMDT) and dimercaptostilbene (DMS). The results show that oligomers yield depend strongly on the used dithiol and on the dithiol-to- nanocluster ratio. Detailed analysis of the reaction yields in combination with simulation suggest that the system reaches a dynamic equilibrium, where ligand exchange happens continuously forming and breaking nanocluster oligomers that are bound together by short chain of disulfide-bridged dithiols. Despite the dynamic nature of the system, dithiol induced polymerization of nanoclusters is a general and straightforward approach to produce covalently- bound multimers of gold nanoclusters. Figure 1: Left: Schematic representation of the possible reaction mechanism. Right: TEM micrographs showing of a) monomers b) dimers and c) trimers d) tetramers of Au~250(p-MBA)n. [1] T. Lahtinen, E. Hulkko, K. Sokołowska, T.-R. Tero, V. Saarnio, J. Lindgren, M. Pettersson, H. Häkkinen, L. Lehtovaara, Nanoscale, 2016, 8, 18665–18674. [2] K.Sokolowska, E. Hulkko, L. Lehtovaara, T. Lahtinen Dithiol-induced oligomerization of para- mercaptobenzoic acid protected gold nanoclusters (J.Phys.Chem. C; accepted) 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Cluster and nanoparticle assemblies A44 Structural and Magnetic Study of Low-dimensional MnSr9 Superatom Cluster-assembled materials 1Loulou Fu, 1Ping Guo, 2Jiming Zheng, 1Puju Zhao, 1Yun Wan 3Zhenyi Jiang 1 School of Physics, Northwest University, Xi'an, 710069, China 2 Institute of Photonics & Photon-Technology, Northwest University, Xi'an, 710069, China 3Institute of Modern Physics, Northwest University, Xi'an, 710069, China The MnSr9 cluster with a symmetric square anti-prism geometrical frame has been proven to be a highly stable magnetic superatom, but no one has yet studied its further assembly[1]. Taking the MnSr9 superatom as a building block, we constructed its zero-dimensional (0D) dimmers, one-dimensional (1D) chain as well as two-dimensional (2D) sheet structures and systematically investigated their electronic and magnetic properties by using the density functional theoretical (DFT )method. the results show that all the MnSr9 cluster self -assembled low dimensional materials have been proved to be thermodynamically stable at room temperature by first-principles molecular dynamics (FPMD) simulations. In particular, these cluster-assembled structures all have ferromagnetic coupling properties. This study provides new insights into the design of precisely controlled low-dimensional magnetic materials. Figure 1 The structures of 1D and 2D MnSr9 self -assembled crystal. [1] V. Medel, J. U.Reveles and S. N. Khanna, Magnetism of electrons in atoms and superatoms, J. Appl. Phys. 112, (2012) 064313. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Cluster and nanoparticle assemblies A45 Doping of Thiolate Protected Gold Cluster through Reaction with Metal Surfaces R. Kazan1, T. Bürgi1 1 Department of Physical Chemistry, University of Geneva, Switzerland Thiolate protected gold nanoclusters have recently gained growing interest due to their dynamic nature [1]. These dynamic molecular systems, can react with each other in solution exchanging metal atoms in a process that is so far not fully understood [2]. Here we introduce a facile technique to examine the role of the thiol ligand in such intercluster reactions based on substituting one of the reacting clusters by a metal surface on which the thiol can be adsorbed easily. The role of the 2-PET ligand in silver and copper doping of Au25(2-PET)18 and Au38(2- PET)24 nanoclusters was investigated by following their reaction with the Ag and Cu metal surfaces, in the presence and the absence of the adsorbed ligand respectively. When the surface is covered by the thiol, Ag doping of both clusters is almost instantaneous and the doping rate gets slower as the surface is being covered by the exchanged Au atoms. In the absence of the 2- PET thiol, the reaction is autocatalytic, the gold clusters decompose on the Ag surface depositing the thiol on it and permitting the doping reaction to start. However, no Cu doping occurs in the absence of 2-PET on the Cu foil. The thiol is essential for doping both heteroatoms into the Au25 and Au38 clusters. Furthermore, XPS study of the Ag surfaces reacted with Au25 was conducted. The Au25 disintegrates on the thiol free surface and both Au and S are detected on it. Furthermore, Au is deposited on the thiolate-covered silver surface, indicating that the adsorbed 2-PET is responsible for doping the cluster by exchanging the heteroatom on the metal surface with an Au atom from the gold cluster. Figure 1: Changehih in the average numberbfdd of doped Ag atoms ((x̄ ))i in the h Au25 clusterlhh throughout the reaction (red). Percentage of Au ratio on the silver surfaces as calculated from the XPS data (insets in blue). [1] Krishnadas, K.R., et al., J. Am. Chem. Soc., 2016, 138, 140-148. [2] Krishnadas, K.R., et al., Nat. Commun., 2016, 7, 13447. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Cluster and nanoparticle assemblies A46 Au-Ag bimetallic nanocluster arrays as highly sensitive surface- enhanced Raman scattering substrates Yuanjun Liua,*, Fen Yea, Yale Shena, Guoxing Zhuc, Chao Yanb, Aihua Yuana 1 School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, P. R. China 2 School of Material Science and Engineering, Jiangsu University of Science and Technology, P. R. China 3 School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, P. R. China We report a convenient and environmental method to prepared Au-Ag bimetallic nanocluster array using self-assembled polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) thin film as template. Firstly, uniform and high density Au nanocluster arrays were formed with in-situ heating at 80 degrees and UV irradiation of AuCl4- loaded PS-b-P4VP nanocylinder arrays film for 3h. Then Ag+ ions were also adsorbed on the P4VP part of the Au nanocluster arrays. Following heating and UV irradiation for 1 h induce the formation of Au-Ag bimetallic nanocluster arrays. The diameter of the Au-Ag bimetallic nanoparticle can be adjusted by the concentration of AgNO3 solution. The Au-Ag bimetallic nanocluster arrays were then used as surface-enhanced Raman (SERS) substrate for detecting R6G, which shows an excellent activity with SERS enhancement factor (EF) up to 3.59 u107. It also shows good reproducibility, favorable stability and high reliability that the signals collected at 120 points over a 50 μm u50μm area give relative standard deviation lower than 11%. Additionally, the bimetallic SERS substrate shows universality and can be used to detect a variety of molecules such as CV and BPE. Figure 1: (a) SEM image of Au-Ag bimetallic nanocluster arrays on patterned PS-b-P4VP template, (b) SERS spectra for R6G detected by the Au nanocluster arrays, Ag nanocluster arrays and Au-Ag nanocluster arrays. [1] S. Schlucker, Surface-enhanced Raman spectroscopy: concepts and chemical applications. Angew. Chem., Int. Ed., 2014, 53, 4756-4795. [2] Y. Yan, A. I. Radu, W. Y. Rao, et al, Mesoscopically bi-continuous Ag−Au hybrid nanosponges with tunable plasmon resonances as bottom-up substrates for surface-enhanced Raman spectroscopy. Chem. Mater., 2016, 28, 7673-7682. [3] Z. Z. Wang, X. Wen, Z. H. Feng, et al, Highly ordered Au-Ag alloy arrays with tunable morphologies for surface enhanced Raman spectroscopy. Chem. Eng. J, 2018, 385, 389-394. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Cluster and nanoparticle assemblies A47 Cluster growth processes in a magnetron sputtering-gas cluster source by direct simulation Monte Carlo method 1,2 1 2 Lianhua zhang , Min Han , Gongping Li 1 National Laboratory of Solid State Microstructures and College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093, China 2 School of Nuclear Science and Technology, Lanzhou University, 730000, Lanzhou, PR China Email: [email protected] Using direct simulation Monte Carlo (DSMC) method, we model the agglomeration and fragmentation processes of Cu atoms, Cu clusters and alloy clusters in an Ar buffer gas. In the following sections, the effect of the various concentrations of Cu ions with negative charge on - the size distribution of CuN clusters are first discussed. This is followed by the analysis of the growth process of alloy clusters (CuNAgM) in a magnetron sputtering-gas cluster source, using DSMC method. The programs are compiled by myself. The content of this paper could be concluded as following: (1) we explored the effect of the ratio of Cu- gas to copper gas on cluster size distribution, as shown in Fig. 1, which illustrates that the size distribution of Cu clusters with negative charge become narrow dramatically on increasing the concentration of the Cu- atoms. The size distribution compares well with a log-normal distribution. The initial ratios (Cu-/Cu) are 40%, 30%, 20%, respectively and the ratio (Cu+/Cu) is 10%. Fig.1 the size distributions of Cu clusters with negative charge. ((a) 40%, (b) 30%, (c) 20%) (2) Alloy Cluster growth processes in cluster source. Here for the first time, we simulate the growth processes of alloy clusters (CuNAgM). the spatial distributions of alloy clusters in cluster source are shown in Figure 2. The length of time step is 10-7s. Figure 2 shows spatial distributions of alloy clusters in the cluster source for time step of 10, 30, 50 and 80 μs. Fig. 2 the spatial distributions of alloy clusters ((a) 10, (b) 30, (c) 50, (d) 80) 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Cluster and nanoparticle assemblies A48 Closely packed nanoparticle aggregations formed by gas phase cluster beam deposition Chang Liu, Zhongqi Xu, Ji’an Chen, Yunhua Chen, Min Han National Laboratory of Solid State Microstructures and Department of Materials Science and Engineering, Nanjing University, Nanjing 210093, China Collaborative Innovation Centre of Advanced Microstructures, Nanjing University, Nanjing 210093, China Gas-phase nanocluster deposition provides a well-developed process able to produce novel cluster-based nanostructures with a high level of control on size, density and functional assembling morphology. [1] Recent experimental results demonstrated that Fe nanoparticle(NP) arrays prepared with cluster beam deposition could form closely packed morphologies, a feature which was usually observed in colloids (in Figure 1). Even more, such aggregation morphologies could also be observed in some non-ferromagnetic materials property. Here we investigate the deposition conditions that affect the aggregation degree of soft-landed clusters. Our results show that the NP aggregation morphologies are affected simultaneously by the deposition rate, migration length on the substrate, as well as the density of surface defects that immobilize the clusters. By controlling a balance among the above conditions, nanoparticle arrays either with random distributions or with closely packed morphologies could be formed. Figure 1: Transmission electron microscopy image of Fe NPs with dense packing morphologies [1] K. Wegner, P. Piseri, H. Vahedi Tafreshi, and P. Milani, J. Phys. D: Appl. Phys., 39, R439(2006) 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Device-oriented topics A49 Selective hydrogen gas sensor using spinel ferrite nanoparticle Ahmad I. Ayesh 1,*, and Mohammad Abu Haija 2 1,* Department of Math., Stat. and Physics, Qatar University, Doha, Qatar, 2 Department of Chemistry, Khalifa University of Science and Technology, Petroleum Institute, Abu Dhabi, United Arab Emirates * Presenting author. Email: [email protected] INTRODUCTION Hydrogen gas sensors based on CuFe2O4 nanoparticle thin films are presented in this work. Those sensors have potential to be used for industrial applications because of their low power requirement, functionality at low temperatures, and low production cost [1, 2]. EXPERIMENTAL/THEORETICAL STUDY 2 Gas sensor devices were fabricated on glass substrates with an area 1 cm each. CuFe2O4 thin films were fabricated by magnetron sputtering inside a Torr International high vacuum system. Argon (Ar) inert gas with a flow rate of 115 sccm was used to introduce the plasma and to sputter the material from a composite CuFe2O4 target fixed on a water cooled sputter head. The base pressure of the vacuum system was approximately 10-6 Torr. Electrical electrodes were fabricated by thermal evaporation of Au through a shadow mask [3]. RESULTS AND DISCUSSION The produced sensors were tested against hydrogen, hydrogen sulfide, and ethylene gases where they were found to be selective for hydrogen. Figure 1 depicts the electrical current response of a representative device as a function of hydrogen concentration, measured at 50 ć and using a constant voltage of 60 mV. The figure reveals that as the device is exposed to hydrogen,the electrical current Fig. 1 Gas response as a function of hydrogen concentrations response signal decreases, and this decrease proportional at 50°C, and sensitivity at different temperatures to hydrogen concentration. The figure also shows the response as a function of hydrogen concentration and temperature. The figure demonstrates that the optimum operation temperature of the presented sensors is around 50 °C. The figure also shows that the sensitivity of the sensor at 50 °C varies linearly with H 2 concentration within the range of the experimental measurements, while the sensitivity of the sensor decreases and becomes nonlinear. Once nanoparticles are exposed to H2 gas, H2 molecules interact with the surface of nanoparticle through oxygen ions that were predesorbed onto nanoparticle surface according the following equations [2]: - - H2(ads) +O (ads) ↔ H2O + e (1) -2 - H2(ads) +O (ads) ↔ H2O + 2e (2) The reactions imbue electrons into the p-type CuFe2O4 which leads to a decrease in conductivity (increase in the resistance). CONCLUSION The fabricated sensors showed their maximum response at low temperature which indicates the low operational power requirement, and their compatibility with the safety requirement to be used as hydrogen gas sensors. In addition, those sensors exhibit linear response with hydrogen concentration which facilitate their calibration when used for practical applications. The production of presented sensors is cost effective, thus they have the potential to be used for practical industrial applications. REFERENCES [1] M.A. Haija et al, Journal of Alloys and Compounds, 690 (2017) 461-468. [2] M.A. Haija et al, Applied Surface Science, 369 (2016) 443-447. [3] M.Y. Haik et al, Materials Letters, 124 (2014) 67-72. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Device-oriented topics A50 High Resolution Multi-Functional Pressure Sensors Based on Percolative Conductions in Metallic Nanoparticle Arrays Minrui Chen1, Weifeng Luo1,MinHan1 1 National Laboratory of Solid State Microstructures and College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093, China Pressure sensors are basic but important elements for various applications such as wearable devices, electronic skins, medical apparatus, meteorological observations, micro-electro- mechanical systems (MEMS), navigation security and so on.[1] In order to meet diverse applied conditions, it is becoming more and more significant to fabricate sensitive pressure sensors with ultrahigh resolutions. In the present work, dense metallic nanoparticle arrays were deposited on the surfaces of deformable membranes and used as piezoresistive actuation layers to detect tiny external pressures. In the percolative metallic nanoparticle arrays, coulomb blockade and quantum tunneling or hopping dominate the electronic conduction mechanism.[2] The conductance of the nanoparticle arrays were sensitively related to the spacing between the nanoparticles.[3] Therefore, the actuation layers could transfer the deformation of the membranes induced by external pressures into the variations of the quantum conductance in the nanoparticle arrays. An extremely high sensitivity ( 23.3 kPa-1 ) was demonstrated with a tactile pressure sensor fabricated by depositing nanoparticles on the polydimethylsiloxane (PDMS), as shown in Figure 1a. A barometer was fabricated by encapsulating an actuation layer on a vacuum or gas-filled reference cavity. It showed the ability to detect differential pressure as diminutive as 0.5 Pa (Figure 1b). It could be used as a high resolution barometric altimeter, which was able to the variation of altitude by measuring the atmospheric pressure difference (Figure 1c). Figure 1: a) Pressure-response curves of a tactile pressure sensor based on PDMS. b) Real- time conductance fluctuating pattern under a diminutive pressure (ΔP= 0.5 Pa) applied on the barometer. c) Real-time conductance changes in response to the variation of altitude by applying the barometer as an altimeter. [1] T. Q. Trung, N. E. Lee, Advanced Materials 2016, 28, 4338; S. Tadigadapa, K. Mateti, Meas. Sci. Technol. 2009, 20. [2] I. S. Beloborodov, K. B. Efetov, A. V. Lopatin, V. M. Vinokur, Physical Review Letters 2003, 91. [3] J. Herrmann, K. H. Muller, T. Reda, G. R. Baxter, B. Raguse, G. de Groot, R. Chai, M. Roberts, L. Wieczorek, Appl. Phys. Lett. 2007, 91. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Electron correlation-magnetism and superconductivity A51 Magnetic interaction in Fe-Cr alloy nanoparticles Zhongqi Xu1, Yunhua Chen1, Jian Chen1, Weifeng Luo1, Chang Liu1,MinHan1 1 National Laboratory of Solid State Microstructures and College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093, China Fe-Cr alloys are of technological interest due to their good corrosion resistance, high mechanical strength and wear resistant properties.[1] Compared with bulk Fe-Cr alloys, Fe-Cr alloy nanoparticles have more potential applications because of their complex structure, diverse phase composition and magnetic exchange interaction between the particles. In our study, Fe-Cr alloy nanoparticles were synthesized with gas aggregation process in a cluster condensation chamber equipped with two magnetron discharge heads, installed with a Fe target and a Cr target, respectively. The TEM characterization revealed that the shape of the nanoparticles was dominated by irregular cubes and spheres. We also observed that the Fe-Cr nanoclusters could form core-shell structures by forming oxide layers of different thicknesses on their surfaces. In the hysteresis loop measurement, a strong exchange bias effect could be observed, accompanied by an increase in coercivity with decreasing temperature, which was ascribed to a spin coupling between oxidized antiferromagnetic shell and ferromagnetic core. Moreover, the spins arranged randomly due to thermal perturbations at high temperatures, which resulted in obvious superparamagnetism. A shift of the hysteresis loop was also observed by changing the proportion of the components in the alloy, and was attributed to the competition between the exchange interaction and the dipolar interaction. [1] B.F.O. Costa, et al., J. Alloy. Compd. 308 (2000) 49. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Electron correlation-magnetism and superconductivity A52 Magnetocaloric Effect of High-nuclearity 4f and 3d-4f Metal Clusters L. S. Long State Key Laboratory of Physical Chemistry of Solid Surfaces and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005,China Magnetocaloric effect (MCE) is a magneto-thermodynamic phenomenon in which a change in temperature of a suitable material is caused by exposing the material to a changing magnetic field. Since first observed by a German physicist Warburg in 1881 [1], the MCE of magnetic materials has attracted much interest in the field of cooling technology. High- nuclearity 4f and 3d-4f metal clusters are a unique class of compounds, and regarded as a promising candidate to replace the expensive and increasingly rare helium-3 in ultralow- temperature (<< 1 K) [2]. In this work, we introduce our recent research progress in the magnetocaloric effect of high-nuclearity 4f and 3d-4f metal clusters, including in, 1) How to efficiently construct high-nuclearity 4f and 3d-4f metal clusters [2-6]; 2) How to reveal the magnetic interaction in the system of high-nuclearity 4f and 3d-4f metal clusters [7,8]; and 3) how to improve the magnetocaloric effect of the high-nuclearity 4f and 3d-4f metal clusters [9]. References [1] Warburg, E. G., Ann. Phys. 1881, 249,141. [2] Peng,J.B.,Ren,Y.P.,Kong,X.J.,Long,L.S.,Huang,R.B.,Zheng,L.S.,Zheng,Z.P.,Angew. Chem. Int. Ed. 2011, 50,10649. [3] Peng, J. B., Zhang, Q. C., Zheng, Y. Z., Kong, X. J., Ren, Y. P., Long, L. S., Huang, R. B., Zheng, L. S., Zheng, Z. P., J. Am. Chem. Soc. 2012, 134, 3314. [4] Peng, J. B., Kong, X. J., Zhang, Q. C., Orendac, M., Prokleska, J., Ren, Y. P., Long, L. S., Zheng, Z. P., Zheng, L. S., J. Am. Chem. Soc. 2014, 136, 17938. [5] Zheng, X. Y., Jiang,Y. H., Zhuang, G. L., Liu, D. P., Liao, H. G., Kong, X. J., Long, L. S., Zheng, L. S., J. Am. Chem. Soc., 2017, 139, 18178. [6] Zheng, X. Y., Xie, J., Kong, X. J., Long, L. S., Zheng, L. S., Coord. Chem. Rev., 2017, doi.org/10.1016/j.ccr.2017.10.023. [7] Liu, D. P., Lin, X. P., Zhang, H., Zheng, X. Y., Zhuang, G. L., Kong, X. J., Long, L. S., Zheng, L. S., Angew. Chem. Int. Ed. 2016, 55, 4532. [8] Zheng, X. Y., Zhang, H., Han, Y. Z., Du, M. H., Wei, R. J., Kong, X. J., Zhuang,G.L.,Long,L.S.,Zheng, L.-S., Angew. Chem. Int. Ed., 2017, 56, 11475. [9] Zheng,X.Y.,Kong,X.J.,Zheng,Z.,Long,L.-S.,Zheng,L.S., Acc. Chem. Res. 2018, 51,517. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Electron correlation-magnetism and superconductivity A53 The cluster decorated inverse magnetoelectric coupling effect in NiFe/PVDF flexible heterostructural films N. Jiang, Y. L. Bai, S. F. Zhao Department Physical Science and Technology, Inner Mongolia University, PR China [email protected],[email protected],[email protected] Inverse magnetoelectric effect plays a key role in magnetic random access memories, sensors and spintronics[1-2]. At room temperature the flexible heterostructural films NiFe/PVDF can obtain the interface stress controlled magnetization change under external electric field. Figure 1(a) showed the XRD patterns of flexible NiFe/PVDF films. NiFe nanoclusters contribute to interface coupling between electrostriction and piezomagnetic phases. What’s more the flexible inverse magnetoelectric materials can integrate into wearable fibber, which will greatly influence lives. In addition, NiFe alloys as a kind of soft magnetic materials possess characters of easy magnetization, which is effective for saving energy. The hysteresis loops were measured at different temperatures in Figure 1(b). The magnetization of NiFe clusters is sensitive to external stress, which is to benefit of electric filed driven magnetic domain switching. These results are vividly presented in Figure 1(c), (d) and (e). Figure 1 (a) XRD patterns of NiFe/PVDF heterostructure, the inserting presents the flexible schematic diagram; (b) The M-H loops at different temperature; The magnetic domains switching controlled by external electric field: (c) E=0 kV/cm, (d) E=+10 kV/cm and (e) E= -10 kV/cm [1] Slawomir Zietek, Piotr Ogrodnik, Witold Skowroński, Feliks Stobiecki, Sebastiaan van Dijken, Józef Barnaś, and Tomasz Stobiecki. Appl. Phys.Lett., 2016, 109, 072406. [2] C. Song, B. Cui, F. Li, X. J. Zhou, F. Pan, Recent progress in voltage control of magnetism: Materials, mechanisms, and performance. Prog. Mater. Sci., 2017, 87, 33-82. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Electron correlation-magnetism and superconductivity A54 Fabrication and characterization of graded diameter Ni magnetic nanowire arrays Xinyue Hu, Yuexing Li, Jingcai Xu, Jun Hu* Department of Chemical Engineering, Zhengjiang University of Technology, Hangzhou 310014,China presenting-author email: [email protected] Designing and regulating the magnetic properties of nanowire arrays was critical for their application. The novel diameter-graded Ni nanowire arrays (DGNWs) with peculiar magnetic behavior was reported. DGNNWs with diameter varying from 20 nm to 100 nm have been fabricated in the anodized aluminum templates (AAT) by direct current electrodepositing. The crystal structure and micrograph of DGNNWs were characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy, and the magnetic characterization was characterized by hysteresis loop and First Order Reversal Curve (FORC). The hysteresis loop revealed the longitudinal coercivity and remanence for DGNNWs are more similar to uniform nanowire arrays with diameter of 20 nm due to the pinning at one end with small nanowire diameter. The angular dependence of coercivity and remanence revealed a significant reduction of coercivity and remanence when θ (the angle between the magnetic field and the long axis of the nanowires) just varied from 0° to 15°. This reduction was related to the change of magnetization reversal mechanism from coherent rotation with θ=0° to transverse domain wall with θ (15° ≤ θ ≤ 90°). The FORC diagram displayed a complex magnetic behavior that had two dierent but close to each other distributions on the direction of Hu (the interaction field). The two dierent distributions on FORC diagram were more obvious with larger diameter difference of thick end and thin end in DGNNWs. The complex magnetic behavior possibly ascribed to the comprehensive effect of the interaction at the thin diameter end and the interaction at the thick diameter end. Consequently, diameter-graded technique was a potential method for independently controlling the various magnetic properties of nanowire arrays. Keywords: magnetic property; diameter-graded Ni nanowire arrays; anodized alumina templates; electrodeposition. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Supported, embedded and ligated clusters and nanoparticles A55 Mechanical stress in nano-size particles G. Laurens1, T.Albaret1, A.-R. Allouche1, J. Lam1, A. Chemin1, C. Martinet1, A. Cornet1, K. Lebbou1, G. Ledoux1, C. Dujardin1, F. Chaput2, B. Gökce3, S. Barcikowski3, and D. Amans1, 1Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon, F-69622 Villeurbanne cedex, France 2Laboratoire de Chimie, UMR5182 Université Lyon 1 - CNRS - ENS Lyon, Université de Lyon, F-69364 Lyon, France. 3Technical Chemistry I, University of Duisburg-Essen and Center for Nanointegration Duisburg-Essen CENIDE, Universitaetsstrasse 7, 45141 Essen, Germany E-mail: [email protected] The Laplace-Young law is known to describe the pressure inside a fluid particle. This internal pressure conjecture is sometimes improperly applied to solid nanoparticles. This arises from confusion between the concepts of surface energy and surface stress state, identical in the case of liquids, but no more identical in solids [1]. To highlight the hazardousness in using Laplace- 3+ Young law for solid nanoparticles, we synthesised nanoparticles of ruby (α-Al2O3:Cr ) by Pulsed Laser Ablation in Liquid. Ruby is known as a continuous pressure sensor due to the pressure dependence of its R fluorescence lines [2]. Using 2-[2-(2-methoxyethoxy) ethoxy] acetic acid as ligands [3], we have successfully synthesized the corundum phase (α) of alumina with sizes smaller than 10 nm. This is a first outstanding result since the cubic phase (γ) of alumina is considered as the thermodynamically stable polymorph for these particle sizes [4]. As expected, we didn’t see the luminescence shift from Cr3+ in nano-rubies that should appear if Laplace-Young pressure applied. Our experimental results are strengthened by numerical simulations. The luminescence shift is induced by the mechanical deformation of the emitter crystallographic site. Vienna Ab-initio Software Package (VASP) calculations were performed to estimate the mechanical stress induced by the nano-rubies surfaces. At first the relaxed structure at (0001) surfaces of pure α-Al2O3 showed the same mechanical relaxation than previous studies [5-6]. Then calculations performed on doped alumina, by substituting an Al atom by a Cr atom on different site, showed that the chromium are preferentially localized in the core of the nanoparticle than in the outer shell. The contribution of the ligands has also been evaluated by capping pure alumina structures with ligands. The results showed that the ligands reduce the mechanical relaxation at the surface and stabilize the volume of the particle. We then deduced that the fluorescence lines of the nano-rubies stabilized by the ligands remain unchanged since the chromium is preferentiallyy located in a bulk environment. (b) Fig. 1: (a) TEM picture of nano-rubies, (b) Mechanical relaxation inside the (0001) alumina cell [1] F.D. Fischer et al., Progress Mat. Sci. 53, 481 (2008). [2] R. Forman et al., Science 176, 284 (1972). [3] D. Amans et al., J. Phys. Chem. C 115, 5131 (2011). [4] J. McHale et al., Science 277, 788 (1997). [5] Ruberto et al., Phys. Rev. B 67, 195412 (2003) [6] Li and Choi, J. Phys. Chem. C 111, 1747 (2007) 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Supported, embedded and ligated clusters and nanoparticles A56 Atomically Precise Synthesis of Trimetallic Cluster by Growth of HPdAu8 Superatom H. Hirai1, S. Takano1, T. Tsukuda1, 2 1 Department of Chemistry, School of Science, The University of Tokyo, Japan 2 ESICB, Kyoto University, Japan [email protected],ac,jp Au and H atoms have similar electronic structures: both of them have one electron in their outermost s orbitals. The interaction between gold clusters and hydrogen has been studied in the gas phase[1] and in the solution phase[2]. Our group found that a reaction of H– with oblate gold 3+ 2+ clusters [Au9(PPh3)8] and [PdAu8(PPh3)8] (1) with non-closed superatomic shell structure 2 4 2+ + (1S) (1P) generated hydride-doped clusters [HAu9(PPh3)8] and [HPdAu8(PPh3)8] (2)with closed superatomic shell structure (1S)2(1P)6. Density functional theory calculationshowed that the hydride behaved as a component of these superatoms like an Au atom. In addition, we found the size-selective growth reactions of each cluster with the gold complex AuCl(PPh3) + + into [Au11(PPh3)8Cl2] and [HPdAu10(PPh3)8Cl2] (3). In this study, we report the reaction of 2 with silver complexes which results in the atomically precise growth into novel trimetallic clusters. The cluster 1 was synthesized following the reported method[3] with slight modifications. The reaction of 1 and NaBH4 afforded the hydride-doped cluster 2. The silver complex AgCl(PPh3) was added subsequently into the dispersion of 2. Electrosprayy ionization mass spectrometry showed the formation + of a trimetallic cluster [HPdAg2Au8(PPh3)8Cl2] (4). Single-crystal X-ray diffraction showed that the geometric structure of 4 is almost isostructural to that of the corresponding bimetallic cluster 3. In both cases of 3 and 4, the doped positions of two MCl (M = Au or Ag) moieties are same and it is assumed that the growth reaction proceed regioselectively. This suggests that hydride-doped superatoms can open a new door for atomically-precise bottom-up multimetallic cluster synthesis. Scheme 1. The growth reaction into 3 and 4 from hydride-doped HPdAu8 superatom (2). [1] Buckart, S. et al. J. Am. Chem. Soc. 2003, 125, 14205. [2] Ishida, R. et al. J. Phys. Chem. Lett. 2017, 8, 2368. [3] Ito, L. N. et al. Inorg. Chem. 1991, 30, 988. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Supported, embedded and ligated clusters and nanoparticles A57 Identify the cluster formation in the process of metal dissolving in high temperature molten salt Yiyang Liu, Tao Su, Hongtao Liu Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China Bismuth metal reacts with dilute solutions of Bi3+ in molten salt can form colored melts[1]. This colored species has characteristic absorption peaks in the visible light region, which can be identified by high-temperature ultraviolet-visible absorption spectroscopy[2]. In this study, solvent used was the liquid eutectic LiCl-KCl containing 10 wt% of BiCl3, then adding excess metal bismuth and heating at a high temperature (450oC). It can be seen that the purple color begins to appear in the lower layer of molten salt and the absorption spectrum of the new 3+ cluster ion is shown in Fig. 1.a, which consistent with [Bi5] cluster, the characteristic 3+ absorption peak is centered at 530 nm. Then the [Bi5] diffused in the molten salt and decomposed to Bi+ by further reaction with Bi3+, it can be seen that the absorption peak of 3+ [Bi5] was disappeared from the absorption spectrum of the molten salt shown in Fig. 1.b. The ESR result shown in Fig. 2. confirmed the existence of Bi+ after the melt cool down. It is speculated that the dissolve of metal bismuth atoms is reacted with Bi3+ to form the aromatic 3+ - 3+ [Bi5] cluster (similar to Bi5 follow the 4n+2 rule). The structure and coordination of [Bi5] will be discussed. 3+ Figure 1: a) The absorption spectrum of [Bi5] ; b) The absorption spectrum of molten salt which reaction lasts for more than 24 hours. Figure 2: The ESR result of solid salt after reaction. [1] Bjerrum, N. J., Boston, C. R. & Pedro Smith, G. Inorg. Chem. 6, 1162–1172 (1967). [2] Boston, C. R. & Smith, G. P. J. Phys. Chem. 66, 1178–1181 (1962). 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Supported, embedded and ligated clusters and nanoparticles A58 Reversing Size-Dependent Trends in the Oxidation of Copper Clusters through Support Effects Nisha Mammen,1,2 Leonardo Spanu,3 Eric C. Tyo,4 Bing Yang,4 Avik Halder,4 Sönke Seifert,5 Michael J. Pellin,4 Stefan Vajda4 and Shobhana Narasimhan2 1 Department of Physics, University of Jyväskylä, Jyväskylä, Finland 2 Theoretical Sciences Unit, J. N. Centre for Advanced Scientific Research, Bangalore, India 3 Shell Technology Center, Shell India Markets Private Limited, Bangalore, India 4 Materials Science Division, Argonne National Laboratory, Argonne, USA 5 X-ray Science Division, Argonne National Laboratory, Argonne, USA Oxidation is known to significantly alter the chemical properties of nanoparticles and their performance as catalysts. The degree of oxidation that maximizes product yield and selectivity is known to vary, depending on the particular reaction. It is therefore highly desirable to gain insight on how to promote or hinder oxidation of these particles. Using a combination of density functional theory, ab initio atomistic thermodynamics and experimental XANES, we have studied the size-dependent oxidation/reduction of subnanometer sizes of Cu clusters in the gas phase and when supported on hydroxylated amorphous alumina [1]. We have shown that in the gas phase, smaller Cu clusters are more resistant to oxidation. However, this trend is reversed upon deposition on an alumina support. We have explained this result in terms of strong clusterϋsupport interactions, which differ significantly for the oxidized and elemental clusters. The stable cluster phases also feature novel oxygen stoichiometries. Our results suggest that one can tune the degree of oxidation of Cu catalysts by optimizing not just their size, but also the support they are deposited on. Figure 1: Sizeϋdependent reduction temperature of oxidized subnanometer copper clusters in gas phase and when supported on hydroxylated alumina. The reduction temperature decreases with cluster size for the supported clusters, in stark contrast with the opposite trend found for free gas-phase clusters from first principles calculations. [1] Nisha Mammen, Leonardo Spanu, Eric C. Tyo, Bing Yang, Avik Halder, Sönke Seifert, Michael J. Pellin, Stefan Vajda and Shobhana Narasimhan, Eur. J. I. C. 1, 16, 2018. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Supported, embedded and ligated clusters and nanoparticles A59 Collision-induced dissociation mass spectrometry on the gold clusters protected + by mixed ligands, [Au11(PPh3)8X2] (X = Cl and CįCPh) R. Tomihara1, K. Hirata1, H. Yamamoto1, S. Takano1, K. Koyasu1,2, T. Tsukuda1,2 1 Graduate School of Science, The University of Tokyo, Japan 2 ESICB, Kyoto University, Japan [email protected] Surface modification of gold nanoclusters is a potential method to tune their stabilities, structures, and physicochemical properties. Anionic ligands such as halides and alkynes not only protect the Au core, but also adjust the number of valence electrons in the Au core. For + example, one of the typical ligand-protected Au clusters, [Au11(PPh3)8X2] , has a Au11 core with 8 electrons protected by mixed ligands of PPh3 and anionic ligand X. In order to gain insight into the binding nature of the neutral and anionic ligands on the cluster, we conducted collision induced dissociation (CID) mass spectrometry and density functional theory (DFT) calculations of + + [Au11(PPh3)8X2] (X = Cl, CįCPh).[Au11(PPh3)8X2] (X = Cl, CįCPh) was chemically synthesized and introduced into a mass spectrometer via an electrospray ionization source. Fragment ions produced by the CID process were observed by a mass spectrometer while changing the nominal collision energy by the voltages applied to ion optics at the injection region (CID voltage). Structures and relative energy of the fragments were studied Figure 1: (a) ESI and (b) CID mass + by DF calculations at B3LYP/lanl2dz (Au), 6-31G* spectra of [Au11(PPh3)8Cl2] (CID (others) level. voltage: 210V). (c) ESI and (d) CID Figure 1 shows typical CID mass spectra of of and (d) mass spectra of [Au11(PPh3)8(C≡ + CPh) ]+ (CID voltage: 250V). CID mass spectra of [Au11(PPh3)8X2] (X = Cl, C=CPh). 2 + All the fragment ions [Aux(PPh3)yXz] observed had 8 valence electrons, indicating that the CID channels are governed by the electronic stability of the fragments. In the case of X = Cl, fragmentation pattern could be explained by the competitive loss of neutral fragments of PPh3 and AuCl(PPh3), which are energetically comparable channels according to the DFT calculations (Figure 2). In contrast, the branching fraction of the loss of the AuX(PPh3) units was significantly smaller for X = CįCPh than that for X = Cl. We ascribed the effect of X on the branching Figure 2: DFT calculation results of Au11 fractions of dissociations of PPh3 and AuX(PPh3) to the cluster and CID fragments. steric difference 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Supported, embedded and ligated clusters and nanoparticles A60 An Au25(SR)18 cluster with a face-centered cubic gold core: synthesis and characterization T. Omoda1, S. Takano1, S. Yamazoe2,3,4, K. Koyasu1,3, Yuichi Negishi5,6, T. Tsukuda1,3 1 Graduate School of Science, the University of Tokyo, Japan 2 Graduate School of Science and Engineering, Tokyo Metropolitan University, Japan 3 ESICB, Kyoto University, Japan 4 CREST, JST, Japan 5 Department of Applied Chemistry, Tokyo University of Science, Japan. 6 Photocatalysis International Research Center, Tokyo University of Science, Japan. [email protected] – Thiolate (RS)-protected gold clusters [Au25(SR)18] have common structural motifs regardless of the R groups: an icosahedral Au13 core with formally 8 electrons system exhibiting an electronic shell – closure [1,2]. An exception can be found in [Au25(SPG)18] cluster (PGSH = N-(2- mercaptopropionyl)glycine) which shows significantly different optical absorption spectrum from the – – conventional [Au25(SR)18] [3]. In this study, we studied structure of [Au25(SPG)18] by UV-vis absorption spectroscopy and X-ray absorption fine structure. – – Figure 1 shows the UV-vis spectra and EXAFS oscillations of [Au25(SPG)18] , [Au25(SC2Ph)18] , – and [Au23(Sc-C6)16] measured at 10 K (PhC2SH = 2-phenylethanethiol, c-C6SH = 1-cyclohexanethiol) – [1, 2, 4]. The spectral profiles of [Au25(SPG)18] are significantly different from those of – – [Au25(SC2Ph)18] having an icosahedral Au13 core, but similar to those of [Au23(Sc-C6)16] having a gold – core with a face-centered cubic (fcc) structure. These results suggest that [Au25(SPG)18] has an fcc gold – core like [Au23(Sc-C6)16] . – Based on characterization results, two model structures of [Au25(SPG)18] are constructed by – elongating staple motifs of [Au23(SR)16] with the fixation of its fcc-type Au15 core capped by four SR (Figure 2). DFT calculation with R = CH3 suggests that Au–S frameworks of these models are – energetically stable as much as that of conventional [Au25(SR)18] . For the formation of an fcc-type gold – core in [Au25(SPG)18] , it is considered that the bulkiness of PGSH is essential [5]. Fig. 1 (a) UV-vis spectra and (b) Au-L3 edge EXAFS oscillations Fig. 2 Au–S frameworks of − − − of [Au25(SPG)18] ,[Au25(SC2Ph)18] ,and[Au23(Sc-C6)16] model structures of − measured at 10 K. [Au25(SPG)18] . [1] Heaven, M. W. et al., J. Am. Chem. Soc., 2008, 130, 3754. [2] Zhu, M. et al., J. Am. Chem. Soc., 2008, 130, 5883. [3] Negishi, Y. et al., J. Phys. Chem. B, 2006, 110, 12218. [4] Das, A. et al., J. Am. Chem. Soc., 2013, 135, 18264. [5] Omoda, T. et al., J. Phys. Chem. C, in press. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Supported, embedded and ligated clusters and nanoparticles A61 A substrate consist of Ir atom and single-vacancy graphene for adsorbing transition- metal atoms vertically 1 2 Y. Han , J-G. Wan 1 Department of physics, Nanchang Normal University, China 2 National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, China Symmetry plays an important role in the properties of the nanomaterials. Special transport and magnetic properties can be brought about by the special symmetry. In 1988, Haldane proposed that the Quantum Anomalous Hall Effect (QAHE) can be realized in a lattice with the spatial inversion symmetry and the broken time-reversal symmetry[2]. There are also many studies shows that a huge magnetic anisotropy energy (MAE), which is the energy barrier for flipping the spin moment between two degenerate magnetic states and hence determine the Curie temperature of the nanomaterials, can be found in many TM dimers and atom chain with a cylindrical symmetry [2]. Adsorbing the dimer or atom chain on the defected graphene to obtain excellent transport and magnetic properties is being paid more and more attention recently. To retain the local cylindrical symmetry on the site of dimmer or atom chain and the global symmetry of the whole system, the axis of the dimer or atom chain must be perpendicular to the graphene plane, which is difficult. There are a few studies showing that some dimmers can forms a stable vertical structure on the defected graphene, such as Ir2 dimmer, Pt-Ir dimmer, and Os−Ru dimmer. For most transition-metal ( TM) dimmers, the axis prefer to be parallel or approximately parallel to the graphene plane. We present a substrate (Ir-SVG) consist of an Ir atom and single-vacancy defect graphene (SVG) to realize the desired configuration with the dimmer axis perpendicular to the graphene plane. Our calculation results show that for 3d TM atoms in the second half of the period, i.e. Fe, Co, Ni, Cu and Zn, the atom tend to locate on the top of the Ir atom forming a perpendicular configuration. But for the first half of the period, i.e. Sc, Ti, V, Cr and Mn, the atom tend to combine with both the C atoms and Ir atom. Further detailed calculations show that the density of state (DOS) of the Ir-SVG near the fermi energy is primarily provided by the dz2 state of the 2 Ir atom. In addition to the dz orbital of the Ir atom, there are little DOS of px, py, pz of the C atoms near the Ir atom. It is known that the dz2 orbital is cylindrical symmetry with the axis of symmetry of z axis. So when the Ir-SVG combines with a TM atom with many d electrons, the electrons transferring between them firstly occupy the dz2 orbital or depart from the dz2 orbital. As a result, the TM atom prefer locating on the top of the Ir atom to on the graphene. When the Ir-SVG combines with a TM atom with few d electron, the p electron of the TM atoms will participate the electron transferring. The TM atom may combine with both the C atoms and Ir atom deviating the vertical configuration. We think for the 4d and 5d TM atoms, the results are similar to the 3d atoms. Our work provides an effective way to look for valuable configurations with high symmetry. [1] Haldane, F. D. M., Model for a Quantum Hall Effect without Landau Levels: Condensed-Matter Realization of the “Parity Anomaly”. Phys. Rev. Lett. 61, 2015–2018 (1988). [2] T. O. Strandberg, C. M. Canali, and A. H. MacDonald, Transition-metal dimers and physical limits on magnetic anisotropy Nat. Mater. 6, 648 (2007). 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Supported, embedded and ligated clusters and nanoparticles A62 The coupling between exchange bias and anomalous Hall effects in Fe-FeO core-shell clusters Y. L. Bai, N. Jiang, S. F. Zhao Department Physical Science and Technology, Inner Mongolia University, PR China [email protected],[email protected], [email protected] Anomalous Hall effect and exchange bias effect have attracted significant interest and widely existed in magnetic random access memories as part of core functionality [1-3]. Since these devices onto the market, investigations about the two phenomenons are on their way. Here at the interface core-shell clusters Fe-FeO, a ferromagnetic core-Fe with an anti-ferromagnetic shell FeO is created and show coexisting exchange bias and Hall effects. More importantly, the structure expresses to enable coupling between anomalous Hall effect and exchange bias, further realizes biased magnetoresistivity and Hall resistivity. The phase structure is showed in Figure 1(a). Aside from the potential application in spintronics, experiment in Figure 1 (b), (c) and (d) provide additional insight into the local interface coupling and spin structure coupling at the ferromagnetic/antiferromagnetic cluster core-shell interface. Figure 1: XRD patterns of Fe-FeO core-shell structure; (b) the exchange bias; (c) the magneroresistance and anomous Hall effect se color freely (the book of abstracts will be distributed only as a pdf file), but use sufficiently low figure resolution so that the size of the resulting pdf would remain below the allowed limit. [1] C. O. Avci, M. Mann, A. J. Tan, P. Gambardella, G. S. D. Beach, A multi-state memory device based on the unidirectional spin Hall magnetoresistance. Appl. Phys. Lett., 2017, 110, 203506. [2] Y. J. Yang, Y. X. Yao, L. Chen, H. L. Huang, B. J. Zhang, H. Lin, Z. L. Luo, C. Gao, Y. L. Lu, X. G. Li, G. Xiao, C. Feng, Y. G. Zhao, Controlling the anomalous Hall effect by electric-field-induced piezo-strain in Fe40Pt60/(001)-Pb(Mg1/3Nb2/3)0.67Ti0.33O3 multiferroic heterostructures. Appl. Phys. Lett., 2018, 112, 033506. [3] Z. M. Tian, L. M. Xu, Y. X. Gao, S. L. Yuan, Z. C. Xia. Magnetic memory effect at room temperature in exchange coupled NiFe2O4-NiO nanogranular system. Appl. Phys. Lett., 2017, 111,182406. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Supported, embedded and ligated clusters and nanoparticles A63 Chemical Synthesis of Supported Ptn (n = 5-12) Clusters from Tiara-like Platinum Thiolate Complexes Y. Akanuma1, T. Imaoka1,2,3, K. Yamamoto1,2 1 Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan.2 ERATO- and 3 PRESTO-JST, Kawaguchi, Saitama 332-0012, Japan. [email protected] Particles with sizes below a few nanometers, which are known as clusters, can exhibit unique physical and chemical properties that change with the addition of an atom. Previous studies on the size-selected clusters involved gas phase synthesis and separation of clusters under ultra- high vacuum, which can only produce clusters in extremely small scale. In this study, Ptn (n = 5-12) supported on carbon were selectively synthesized at atomic-precision, in the yield on a milligram scale by using tiara-like platinum thiolate complexes as the precursor. Tiara-like platinum-thiolate complexes, [Pt(SC8H17)2]n (n = 5-12), were synthesized and isolated by recycling size exclusion chromatography. To convert the isolated complexes to clusters, the complexes were deposited onto a carbon support called ketjenblack, and were calcined under 3% H2/N2 stream flow at low temperature. By using the scanning transmission electron microscopy (STEM), the obtained Pt clusters were observed at atomic resolution (Figure 1). Figure 1. Synthesis of supported platinum clusters by reductive calcination of platinum thiolate complexes. HAADF-STEM images of Ptn (n = 5-12) supported on ketjenblack. [1] T. Imaoka, Y. Akanuma, N. Haruta, S. Tsuchiya, K. Ishihara, T. Okayasu, W. J. Chun, M. Takahashi, K. Yamamoto, Nat. Commun. 2017, 8. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Electronic structure and quantum effects A64 The Concentric Bond. A Useful Concept In the Formation of Multilayered Structures A. Muñoz-Castro1 1 aGrupo de Química Inorgánica y Materiales Moleculares, Facultad de Ingenieria, Universidad Autonoma de Chile, El Llano Subercaseaux 2801, Santiago, Chile. [email protected]; [email protected] The seminal concept of chemical bond[1] dates back from more than a century ago, being the central conception in the formation of molecular structures from individual atoms. Interestingly, such notion of chemical bond involves the interaction between orbitals of separated nuclei, with different origin. Herein, we introduce the concept of Concentric Bond, involving the interaction of orbitals which remain coincident to a common origin. This new chemical bond concept, the first new notion of chemical bond in a century, is introduced along the superatom concept (SAC)[3], which further rationalize the bonding in clusters composed by several structural 3+ layers. We will apply this concept to the full-shell icosahedral clusters, [Au13(dppm)6Cl2] and - [Au55(PPh3)12Cl6] (1) both landmark species characterized in the beginning of the 80’s, depicting two and three structural shells, respectively.[2] Their electronic structure can be ascribed as 1S21P6 and 1S21P61D102S22P61F141G10, according to SAC,[3] unraveling the nature of each electronic shell as bonding, non-bonding and antibonding combinations between the different structural layers. For 1, its Au55 core can be described as a combination of Au@Au12@Au42 structural layers (Fig. 1), which in turn leads to the overall 1S, 2S and 3S levels, resulting from the combination of concentric S-type (atomic and superatomic) functions, which denotes an overall bonding, non-bonding and antibonding interaction between the respective shells (Fig. 1). The same is observed for P- type (Fig. 1), and related shells. Hence, from the concentric bonding lecture of the electronic configuration of 1, the bonding character within the core is given by 1S1P1D1F and 1G functions, and retained by 42-cluster electrons. It is important to note, that each case needs to be evaluated in order to determine the character of each electronic shell. In addition, thiolate- protected gold clusters; Au25(SR)18, Au12Cu32(SR)30, Au67(SR)35, Au102(SR)44, Au133(SR)52, Au144(SR)60 and CuAu144(SR)60, were revisited. Fig. 1:Multilayer architecture of the Au55 core from 1, leading to the combination of different concentric orbital functions (M) from Au, Au12 and Au42. Radial nodes denoted as black circles in the contourplots. [1] D.M.P. Mingos, The Chemical Bond I, Springer International Publishing, Cham, 2016. [2] G. Schmid, The relevance of shape and size of Au55 clusters, Chem. Soc. Rev. 37 (2008) 1909. [3] T. Tsukuda, H. Häkkinen, Protected Metal Clusters: From Fundamentals to Applications, Elsevier, 2015. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Electronic structure and quantum effects A65 Structure and stability of main group nanoalloys composed of Na, Mg, Al, Si through genetic algorithms and electronic structure calculations B. R. L. Galvão1 1 Federal Center for Technological Education of Minas Gerais, CEFET-MG, Brazil The search for low energy geometrical structures of nanoclusters is a very complicated problem, due to the large number of coordinates presented by such systems. If alloys are considered the search space is much larger due, including the presence of isomers that arise from permutation of different atoms (homotops). In this work we develop and apply genetic algorithms for the search of stable structures of bimetallic alloys of main group elements such as AlxSiy, AlxMgy [1] and NaxKy [2-3]. A wide range of size and compositions of such clusters are assessed with DFT and MP2 methods, and even some accurate CCSD(T) calculations for small systems. After evaluating a number of potential global minima candidates in each case, we have predicted properties such as binding energy, excess energy, HOMO-LUMO gap and ionization potentials. Our calculations are often able to match experimental results as well as to predict potential candidates to be obtained experimentally. Several approaches to the global optimization problem are explored, including thorough homotop search, previous assessment using an empirical potential, and also direct application of genetic algorithms to the electronic structures calculations. [1] M. A. M. Paiva, B. M. T. C. Peluzo, J. C. Belchior and B. R. L. Galvão, Phys. Chem. Chem. Phys., 18, 31579- 31585, 2016 [2] M. X. Silva, B. R. L. Galvão and J. C. Belchior, Phys. Chem. Chem. Phys., 16, 8895-8904, 2014 [3] F. T. Silva, B. R. L. Galvão, G.P. Voga, M. X. Silva, D. D. C. Rodrigues, J. C. Belchior, Chem. Phys. Lett. 639, 135-141, 2015 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Electronic structure and quantum effects A66 Structural Rearrangement of Au−Pd Nanoparticles under Reaction Conditions: An AIMD Study Cong-Qiao Xu1, Roger Rousseau2, Jun Li1* 1 Department of Chemistry, Tsinghua University, Beijing 100084, China 1 Institute for Interfacial Catalysis, Pacific Northwest National Laboratory, Richland, Washington 99352, United States The structure, composition, and atomic distribution of nanoalloys under operating conditions are of significant importance for their catalytic activity. In the present work, we use ab initio molecular dynamics simulations to understand the structural behavior of Au−Pd nanoalloys supported on rutile TiO2 under different conditions. We find that the Au−Pd structure is strongly dependent on the redox properties of the support, originating from strong metal−support interactions. Under reducing conditions, Pd atoms are inclined to move toward the metal/oxide interface, as indicated by a significant increase of Pd−Ti bonds. This could be attributed to the charge localization at the interface that leads to Coulomb attractions to positively charged Pd atoms. In contrast, under oxidizing conditions, Pd atoms would rather stay inside or on the exterior of the nanoparticle. Moreover, Pd atoms on the alloy surface can be stabilized by hydrogen adsorption, forming Pd−H bonds, which are stronger than Au−H bonds. Our work offers critical insights into the structure and redox properties of Au−Pd nanoalloy catalysts under working conditions. Figure 1. Structural rearrangement of Au32Pd6 cluster under reaction conditions. [1] Wang, Y.-G. et al, J. Am. Chem. Soc. 2013, 135, 10673-10683. [2] Green, I. X. et al, Angew. Chem. Int. Ed. 2011, 50, 10186-10189 [3] C.-Q. Xu, M.-S. Lee, Y.-G. Wang, D. Cantu, J. Li, V. A. Glezakou, R. Rousseau. ACS Nano, 2017, 11, 1649- 1658. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Electronic structure and quantum effects A67 Spin-dependent transport properties of a grapheme Electrode-Single quintuple bond [PhCrCrPh]Molecule Junction H. Wan1, X. Chen2, G. Zhou3 1 Department of Science/Yuzhang Normal University, P.R. China 2 Department of Physics and Electronic Information Science/Huaihua University, P.R. China 3 Department of Physics and Key Laboratory for Low-Dimensional Quantum Structures and Manipulation (Ministry of Education), and Synergetic Innovation Center for Quantum Effects and Applications of Hunan/Hunan Normal University, P.R. China We apply a first-principles computational approach to study spin-dependent electron transport properties of a single quintuple bond [PhCrCrPh] molecule with the trans-bent and linear configurations sandwiched between two ferromagnetic zigzag graphene nanoribbon electrodes. Theoretical results suggest that the current through the trans-bent configuration is significantly larger than the corresponding linear one. The device shows a perfect two-state molecular conformational switch, and a maximum predicted ON/OFF ratio of currents can be up to around 2.4h104/7h104 for majority-spin (α)/minority-spin (β) state. Interestingly, the device shows an obvious spin-polarization behavior and negative differential resistance (NDR) effect. The spin filtering efficiency (SFE) can reach up to 100%, and the maximum value of the peak-to-valley ratio of NDR is up to about 46. These results suggest that our proposed device have attractive potential in molecular switch as well as spin-filtering. Figure 1: (Color online) The calculated spin-resolved current-voltage characteristics of the proposed molecular switch, where (a) ON state corresponds to the trans-bent configurations of (PhCrCrPh) molecule and (b) OFF state to the linear conformation. And (c) shows ON/OFF switch ratios as a function of applied bias voltage from -1.0 to 1.0 V. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Electronic structure and quantum effects A68 Geometrical and electronic properties of hollowed Metal sulphide CdS and CuS electrode nanomaterials Run-Ning Zhao1, Ju-Guang Han2 1Department of Mathematics and Physics,Shanghai DianJi University, Shanghai 201306, PR China . 2National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, People’s Republic of China E Mail/ ([email protected]) As advanced materials for energy storage or conversion applications, metal sulfides with hollow structures are as widely used as supercapacitors and sensors. The geometries and electronic properties of (CdS)2n (n=5-27) nanocages are calculated by density functional theory with the gradient corrected Perdew-Burke-Ernzerh of exchange-correlation functional and including the relativistic effect. The obtained results showed that the inner radius and charge-transfers, surface stabilities along with ionic semiconductor and metallic properties of the hollowed (CdS)2n are increased as cage size being increased. The distinct metallic features in large-size (CdS)2n are revealed. Particularly, the calculated energy gaps for (CdS)2n are generally decreased as the size of (CdS)2n being increased, together with absorption spectra moving from short to long wavelength. The photon to current conversion efficiency related energy conversion is discussed. Interestingly, the encapsulated double-layer CdS nanocages have bigger capacity for energy conversion than the monolayer nanocages. However, the hollowed CuS nanomaterials can be presented as different geometrical forms (CuS)3n by self-assembly their building blocks. Keywords: Geometries and electronic properties; HOMO-LUMO gaps;charge-transfer; energy conversion; [1] RN Zhao, JG Han,YH Duan, Adv. Theo & Simulation,1, 1800001, (2018). [2] RN Zhao, R Chen,Q Li,YH Duan, JG Han, Journal of Alloys and Compounds, 762,754.(2018). 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Electronic structure and quantum effects A69 Exploring electronic structures of transition-metal-doped silver clusters: Effect of electron count studied by chemical reaction of cations and anions K. Minamikawa, M. Horioka, T. Kawano, M. Arakawa, A. Terasaki Department of Chemistry, Graduate School of Science, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan It is known for metal clusters such as silver that delocalized free electrons occupy discrete energy levels in a quantum well due to confinement in a small volume. When a transition-metal atom is doped in the free electron system, it is not trivial whether the d electrons are localized on the dopant atom or hybridized with the free s electrons. This is because s‒d electron interaction should be modified from that in bulk solids, where this type of system is known as the Kondo system such as dilute magnetic alloys. This problem in the cluster regime was first investigated by measurement of size-dependent abundance after photofragmentation. + Transition-metal-doped silver cluster cations, AgNM (M = Sc, Ti, V, Fe, Co, and Ni), showed rich abundance at the size with 18 valence electrons, which suggested delocalization of 3d electrons due to electronic shell closure [1]. Anionic clusters were studied as well by photoelectron spectroscopy, where such electronic shell closure was identified by combining DFT calculation [2]. Motivated by these studies, we propose to study both cations and anions by a common probe for elucidating the effect of electron count systematically. To this end, we +/− investigate electronic structures of AgNM via chemical reaction with oxygen molecules, where open/closed electronic shell would exhibit high/low reactivity. +/− Experiment was performed by generating AgNM by co-sputtering of silver and transition-metal targets in a magnetron-sputtering cluster ion source. After mass selection by a quadrupole mass filter, size-selected reactant ions were stored in a linear rf ion trap for reaction with oxygen molecules. Product ions were extracted from the ion trap for analysis by a time- of-flight mass spectrometer equipped with a reflectron. DFT calculations were performed by the Gaussian 16 package. + In the case of M = Ni, cationic AgNNi exhibited a sharp drop in the reactivity as the size changes from N = 7 to 9. This behavior indicates encapsulation of the Ni reaction site at N + ≥ 8 as revealed by DFT calculation. It should be noted that Ag9Ni showed the lowest reactivity. This is consistent with electronic-shell closure of the cluster consisting of 18 valence electrons, − suggesting delocalized Ni 3d [3]. On the other hand, the reactivity of anionic AgNNi changed − only within an order of magnitude. This is because AgNNi has a rather open geometric structure and, therefore, the Ni atom is hardly encapsulated. It should be noted that odd-electron clusters exhibited reactivity higher than even ones at N ≥ 8, which is probably due to an unpaired electron present in the former but absent in the latter. In contrast, an opposite trend appeared at N ≤ 6. From the results of DFT calculation, the higher reactivity in even-electron clusters (odd N) might be caused by the two unpaired electrons both on the Ni atom and on the Ag host, whereas only one is present on Ni in odd ones (even N). The study is currently being extended to +/− +/− AgNCo and AgNSc to characterize the doped clusters systematically. [1] E. Janssens, S. Neukermans, H. M. T. Nguyen, M. T. Nguyen, P. Lievens, Phys. Rev. Lett. 94, 113401 (2005) [2] K. Tono, A. Terasaki, T. Ohta, T. Kondow, Chem. Phys. Lett. 449, 276 (2007) [3] S. Sarugaku, R. Murakami, J. Matsumoto, T. Kawano, M. Arakawa, A. Terasaki, Chem. Lett. 46, 385 (2017) 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Electronic structure and quantum effects A70 Point–group Specific Symmetry Analysis of DFT Wave Functions of Au and Ag Nanoclusters S. Kaappa, S. Malola, H. Häkkinen Nanoscience Center, Departments of Physics and Chemistry University of Jyväskylä, Finland [email protected] It has long been known that the valence electrons are delocalized in metal cores of nanoclusters, constituting the so-called superatom states. The convention in analyzing the symmetries of these wave functions has been to project them on metal-core-centered spherical harmonics [1], which is a successful routine while dealing with nearly spherical clusters. In this work [2], we expand the toolbox of characterizing the Kohn-Sham wave functions delocalized inside the metal core by assigning point- group specific symmetry representations to the states of both unprotected and ligand-covered metal nanoclusters. We validate that the wave functions inherit the symmetry of the atomic configuration, and that the state characterization using the symmetry representations can better describe the shape of a wave function compared to the projection to spherical harmonics. We also show that the selection rules for optical transitions derived from the character table correlate with the transition analysis based on the time-dependent density functional perturbation theory [3] also for point groups lacking the inversion center. Finally, we will discuss how the stability of the largest structurally resolved thiolated clusters is related to the symmetry of the clusters in terms of our results. 3+ Figure 1: Crystal structure of [Ag141Br12(S-Adm)40] [4]. Kohn-Sham wave function of the LUMO+1 state of Ag141, shown from different perspectives. Character table of D5 point group, for which the LUMO+1 state satisfies the A2 representation. [1] M. Walter, et al., PNAS 105, 27 (2008) [2] S. Kaappa, S. Malola and H. Häkkinen, manuscript in preparation [3] S. Malola, et al., ACS Nano, 7, 11 (2013) [4] L. Ren, et al., J. Am. Chem. Soc. 139, 38 (2017) 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Electronic structure and quantum effects A71 Anomalous quantization trajectory in Co cluster decorated BiSbTeSe2 Shuai Zhang, Rui Wang, Fengqi Song Department of Physics, Nanjing University, China Through the application of Co nanoclusters, anomalous quantization trajectory for the top and bottom surfaces of the topological insulator BiSbTeSe2 (BSTS) has been observed with optimized surface transport. Using renormalization group flow diagrams, two sets of converging points were extracted in (σxy, σxx) space, in which the top surface exhibited an anomalous quantization trajectory while the bottom surface retained the 1/2 quantization. Co nanoclusters induce a sizeable Zeeman gap through antiferromagnetic exchange coupling, which delays the Landau level (LL) hybridization on the top surface for a medium magnetic field. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Electronic structure and quantum effects A72 Chiral Symmetry Breaking Yields a Perfect Golden Shell of Singular Rigidity: I–Au60 S. Mullins1, H.-Ch. Weissker2, I. L. Garzón3, R. L. Whetten1, X. López-Lozano1 1Department of Physics & Astronomy, University of Texas, San Antonio, TX, 78249 USA 2Aix Marseille University, CNRS, CINaM UMR 7325, Marseille, France. 3Instituto de Física, Universidad Nacional Autónoma de México, D.F., México [email protected] The combination of profound chirality and high symmetry on the nm-scale is virtually unprecedented and would open exciting avenues, both fundamental and applied. Here we show how the unique electronic structure and bonding of quasi-2D gold makes it possible. We report an astounding consequence: a chiral symmetry-breaking, i.e. the predicted spontaneous formation of a chiral-icosahedral shell (I–Au60) from achiral (Ih) precursor forms, accompanied by a contraction in the Au-Au bonding and hence the radius of this perfect golden sphere, in which all 60 atomic sites are chemically equivalent. The singular rigidity of I–Au60 is manifested in uniquely discrete structural, vibrational, electronic, and optical signatures, which are reported herein as a guide to its experimental detection and ultimately its isolation in material forms. Its high electronegativity suggests routes to obtaining it as spherically aromatic (6-,12-) I–Au60 salts of various inert counter-cations, as will also be presented. (a) Ih–Au60 constitutive shell from I–Au144(SR)60 [1,2]; (b) and (d) are ball-and-stick atomic models of the Au60 shell, before and after atomic relaxation. Related Archimedean polyhedra are shown in (c) and (e); (f) shows the summed electron densities of HOMO (5) and LUMO (3) states of the I–Au60 shell, as viewed along one of the C5 symmetry-axis.[3,4] [1] H.-Ch. Weissker et al., Nat. Comm. 5, 3785, 2014. [2] H.-Ch. Weissker et al., J. Phys. Chem. C 119, 11250-11259, 2015. [3] S. M. Mullins, H.-C.Weissker, R. Sinha-Roy, J. J. Pelayo, I. L. Garzón, R. L. Whetten, X. López-Lozano, “Chiral Symmetry Breaking Yields an I–Au60 Perfect Golden Shell of Singular Rigidity”, accepted, Nat.Comm. (2018) [4] The authors acknowledge the contributions of all co-authors of reference [3]. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Electronic structure and quantum effects A73 A Silicon cluster based single electron transistor with potential room temperature switching Zhanbin Bai(ⲭঐᮼ)1, Xiangkai Liu (ࡈ㘄ࠟ)2, Zhen Lian (䘎䴷) 3, KangKang Zhang(ᕐ ᓧᓧ) 1, Guanghou Wang (⦻ᒯ)1, Su-Fei Shi(ਢཉ伎) 3, Xiaodong Pi(Ⳟᆍь) 2, Fengqi Song(ᆻࠔ哂)1** 1 National Laboratory of Solid State Microstructures, School of Physics and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China 2 State Key Laboratory of Silicon Materials and School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 , China 3 Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, NY 12180, USA We demonstrate the fabrication of a single electron transistor device based on a single ultra- small silicon quantum dot connected to a gold break junction with a nanometer scale separation. The gold break junction is created through a controllable electromigration process and the individual silicon quantum dot in the junction is deter-mined to be a Si170 cluster. Differential conductance as a function of the bias and gate voltage clearly shows the Coulomb diamond which confirms that the transport is dominated by a single silicon quantum dot. It is found that the charging energy can be as large as 300 meV, which is a result of the large capacitance of a small silicon quantum dot (1.8 nm). This large Coulomb interaction can potentially enable a single electron transistor to work at room temperature. The level spacing of the excited state can be as large as 10 meV, which enables us to manipulate individual spin via an external magnetic field. The resulting Zeeman splitting is measured and the g factor of 2.3 is obtained, suggesting relatively weak electron-electron interaction in the silicon quantum dot which is beneficial for spin coherence time. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Environmental studies A74 Atomic oxygen resistant polyimide nanocomposite films via molecule-level modification by trisilanolphenyl POSS: preparation and properties B. Wu1, Y. Zhang 2, Y. Yang1, Q. Yu1, J. Liu 2 1 Space Materials and Structures Protection Division, Beijing Institute of Spacecraft Environment Engineering, 104 Youyi Road, Haidian District, Beijing 100094, China 2 School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China, [email protected], Atomic oxygen (AO) represents one of the most widely distributed microparticles (~106~108 atoms/cm3) in low earth orbit (LEO) and occupies up to 90% of the LEO atmosphere at the altitude of 500 km. An energy of ~5 eV might be induced when the collisions occur between the AO particles and the external surfaces of spacecrafts operating at a velocity of 8 km/s. This energy is high enough to cause the chemical bond scission of common spacecraft polymer materials, such as polyimide (PI) films, which have been widely used in spacecrafts as thermal control coatings. However, the intrinsic drawback of standard poly(pyromellitic dianhydride- oxydianiline) (PMDA-ODA, tradename: Kapton®) film is their poor AO resistance. In the current work, a series of AO-resistant PI nano-composite films via the modification of a partially condensed polyhedral oligomeric silsequioxanes (POSS) additive, trisilanol- phenyl- POSS (TSP-POSS) was developed (Figure 1). It was found that the nano-scale TSP- POSS additive was highly soluble in the PAA good solvents, such as N,N-dimethylacetamide (DMAc). Thus, homogeneous PAA/TSP composite solutions were obtained even at a high loading content of 25 wt% of TSP-POSS (Figure 2a). Clear and transparent PI/TSP films with a transmittance up to 85% at 500 nm were successfully cast from the PAA/TSP precursors (Figure 2b), indicating that a molecule-level modification was achieved. Incorporation of TSP- POSS greatly improved the AO resistance of the PI films. An AO erosion yield of 2.2h10-25 cm3/atom was achieved by PI-25 containing 25wt% POSS, which is more than one order of magnitude lower than that of the standard PMDA-ODA film (3.0h10-24 cm3/atom) (Figure 3a). Scanning electron microscope (SEM) measurements indicated that an inert silica protecting layer formed onto the surface of the composite films when being irradiated with AO at a flux of 4.0h1020 atoms/cm2 (Figure 3b). We conclude that the current results provide an instructive and efficient methodology for developing high performance polymer films for LEO spacecrafts. Figure 3. AO erosion yield Figure 1. Synthesis Figure 2. PAA/TSP solution and films (a) and UV-Vis spectra of PI/TSP films (b). of PI/TSP (a) and SEM of PI/TSP films. image of PI-25 (b). 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Environmental studies A75 Morphology-Conserved Transformations of Fe(III) alkoxide precursor to Hierarchically Fe3O4 Micro/Nanostructures for wastewater treatment J. F. Zhao1, H. B. Lu1,2, X. K. Meng1 1 Institute of Materials Engineering, National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Nanjing University, Jiangsu, P. R. China 2 Hai an High-tech research institute, Nanjing University, Jiangsu, P. R. China [email protected]; [email protected] Over the last decade, hierarchically micro/nanostructures have drawn widely attention owing to their outstanding properties such as high surface areas, enhancing mass transportation, reducing resistance to diffusion, which endowing them with technological importance in energy storage, catalysis, photocatalysis, adsorption, separation and biomedicine [1,2]. In this paper, well- defined hierarchically Fe3O4 micro/nanostructures have been fabricated by morphology- conserved transformations of iron alkoxide precursors. When tested as adsorbent in organic pollutant, the hierarchically Fe3O4 micro/nanostructures show superior adsorption performance, which is much higher than those reported for other micro/nanostructured metal oxides. The adsorption kinetics and isotherm were also investigated. The high uptake capacity make it a potentially attractive adsorbent for the removal of organic pollutant from water. Figure 1: (a) SEM and TEM (insert) images of hierarchically Fe3O4 micro/nanostructures, (b) -1 UV-vis adsorption spectra of organic pollutant (200 mg L ) treated by hierarchically Fe3O4 micro/nanostructures at various time intervals. [1] X. Li, B. Zhang, C. Ju, et. al. Morphology-controlled synthesis and electromagnetic properties of porous Fe3O4 nanostructures from iron alkoxide precursors, J. Phys. Chem. C 2011, 115, 12305-12357. [2] M. Sun, S. Huang, L. Chen, et. al. Application of hierarchically structured porous materials from energy storage and conversion, catalysis, photocatalysis, adsorption, separation, and sensing to biomedicine, Chem. Soc. Rev. 2016,45, 3479-3563. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China POSTER SESSION B Thursday Auguest 16th 2018 18:00 – 20:00 Energy-related topics (B1 – B6) Optical properties and plasmonics (B7 – B14) Other emerging nanometer-scale systems (B15 – B17) Reactivity and catalysis (B18 – B39) Spectroscopy and dynamics (B40 – B48) Structure and thermodynamics (B49 – B58) Nanoparticles / nanocrystals / nanostructures (B59 – B72) Others (B73 – B74) Energy-related topics B1 Ultra-Dispersed Size-Selected Au Nanoclusters modified FTO as High Performance Anode Catalyst for Direct Methanol Fuel Cells Anupam Yadav1, Yejun Li2, Ting-Wei Liao1, Kuo-Juei Hu1, Jeroen E. Scheerder1, Olga V. Safonova3, Ewald Janssens1, Didier Grandjean1, Peter Lievens1 1Laboratory of Solid-State Physics and Magnetism, KU Leuven, Belgium 2 Hunan Key Laboratory of Super Microstructure and Ultrafast Process, School of Physics and Electronics, Central South University, Changsha, Hunan, China 3Swiss Light Source, Paul Scherrer Institute, Switzerland [email protected] A high performance anode catalyst for electrochemical oxidation of methanol was designed by depositing an atomic monolayer (~1015 atoms/cm2) of highly dispersed size-selected Au Nanoclusters (AuNCs) of ~500 atoms on Fluorine doped Tin Oxide (FTO) using the innovative magnetron cluster beam deposition (CBD) technology. The structural and catalytic properties of the AuNCs modified anode catalyst were characterized by a combination of aberration- corrected Scanning Transmission Electron Microscopy (STEM), Scanning Electron Microscope (SEM), X-ray Absorption Spectroscopy (XAS), and Cyclic Voltammetry (CV). The electron microscopy demonstrates unique surface modification of FTO by isolated and monodispersed 3.1±0.3 nm Au nanoclusters. Au L3-edge XANES (X-ray Absorption Near Edge Structure) of AuNCs shows a red shift in energy and damped oscillations compared with Au foil reference confirming their nanosize and specific electronic properties. CV measurements demonstrate the excellent catalytic activity of the AuNCs modified FTO electrode that is capable of oxidizing methanol at very low potentials of 180 mV vs reference calomel electrode. We anticipate that our approach to modify appropriately and precisely a variety of supports [1] with a minimum use of expensive metals may be applied to a wide range of high performance energy [2], environment [3] and healthcare applications [4]. 1.2 100 - 1.0 A cm 75 P 0.8 AuNCs 50 0.6 Au Foil 0.4 25 0.2 ( density Current 0 Normalized absorbance (A.U.) absorbance Normalized 0.0 -0.2 0.0 0.2 0.4 11900 11920 11940 11960 11980 Energy (eV) Potential (V) vs SCE Figure 1: (Left) Sub Angstrom resolution STEM-HAADF image of size selected AuNCs @TEM grid. (Middle) Au L3 XANES of AuNCs @silicon wafer (Right) Electro-oxidation of 5 M CH3OH in 0.5 M KOH by material monolayer of size selected AuNCs @FTO and bare FTO at room temperature, sweep rate 5mv s-1. [1] Liao, T.-W. et al. Unravelling the nucleation mechanism of bimetallic nanoparticles with composition-tunable core- shell arrangement. Nanoscale 10, 6684 (2018). [2] Perez-Alonso, F. J. et al. The Effect of Size on the Oxygen Electroreduction Activity of Mass-Selected Platinum Nanoparticles. Angew Chem Int Ed 51, 4641 (2012). [3] Liao, T. W. et al. TiO2 Films Modified with Au Nanoclusters as Self-Cleaning Surfaces under Visible Light. Nanomaterials-Basel 8, (1), 30 (2018). [4] Cosentino, S. et al. Role of AuxPt1–x Clusters in the Enhancement of the Electrochemical Activity of ZnO Nanorod Electrodes. J. Phys.Chem. C 121, 15644 (2017). 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China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l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³&UHDWLRQ RI ,QWHUQDWLRQDO 5HVHDUFK &HQWHU IRU $WRP (QGRKHGUDO )XOOHUHQH 1DQRELRWURQLFV´ ZDV VHOHFWHG DV D 3URJUDP IRU .H\ ,QWHUGLVFLSOLQDU\ 5HVHDUFK LQ 7RKRNX 8QLYHUVLW\ -DSDQ 0RUHRYHU LQ $SULO WKH ³&HQWHU IRU )XQGDPHQWDO DQG $SSOLHG 5HVHDUFK RI 1RYHO 1DQRFDUERQ 'HULYDWLYHV´ ZDV UHFRJQL]HG E\ 7RKRNX 8QLYHUVLW\ EDVHG RQ WKLV SURJUDP 7KHVH SURMHFWV DUH DLPLQJ DW WKH HVWDEOLVKPHQW RI D ZRUOG FODVV UHVHDUFK FHQWHU GHGLFDWHG WR WKH ILHOG RI WKH QDQRFDUERQ VFLHQFH :H ZLOO DOVR SUHVHQW RXU UHFHQW UHVHDUFK SURJUHVV RQ DSSOLFDWLRQ RI /L #& LQ D PROHFXODU VHQVRU DQG HOHFWULFDO VWRUDJH GHYLFH >@ : .UlWVFKPHU HW DO 1DWXUH >@ 6 $R\DJL HW DO 1DWXUH &KHPLVWU\ >@ + 2NDGD HW DO 56& $GYDQFHV >@ KWWS ZZZOLFMS WK ,QWHUQDWLRQDO 6\PSRVLXP RQ 6PDOO 3DUWLFOHV DQG ,QRUJDQLF &OXVWHUV $XJXVW +DQJ]KRX &KLQD Energy-related topics B3 Giant Cryogenic Magnetocaloric Effect in Single Crystal and Nano-scale GdVO4 M. Y. Ruan,1 H. Y. Li,1 H. S. Chen,1 Z. W. Ouyang2 1 College of Physics and Electronic Engineering, Northwest Normal University Lanzhou 730070, P. R, China 2 Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074, P. R. China [email protected] AbstractThe magnetic refrigeration MR) technique applied in low temperature region is keep gaining interest as the physical principle of choice for space science, academic research, liquefying gas and other applications. Here, we choose the single crystal and nano-scaled sample to study the size influence to the magnetocaloric effect (MCE) of the material. Nano- scaled samples were prepared by hydrothermal synthesis method. GdVO4 sample is in the space group of I41/amd at room temperature and the structure is consisted of VO4 tetrahedra and GdO8 bisdisphenoid polyhedral. The isothermal M(H) curves for single crystal GdVO4 exhibit that there is a spin flop transition below Néel temperature TN = 3 K for each direction. The M(H) curves saturate at low temperature and with the temperature increase, the M(H) curves present paramagnetic feature. The spin flop transition in single crystal GdVO4 disappears in nano- scaled sample and still presents an AFM transition at TN = ~3 K. The effective magnetic moment decreases from 8.02 μB in single crystal to 7.03μB in nano-scaled sample. The magnetic -1 -1 -1 -1 entropy -ΔSM = 60.91 JKg K and 40.94 JKg K in single crystal for the direction of H//c and Hc, respectively. Obviously, the entropy has been suppressed in nano-scaled sample which means that the size effect can be used to control the MCE in GdVO4 sample. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Energy-related topics B4 Ether-soluble Cu53 Nanocluster and Derived High-quality CuI Film in Perovskite Solar Cells Peng Yuan,1 Ruihao Chen,1 Nanfeng Zheng 1 1 State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, National & Local Joint Engineering Research Center of Preparation Technology of Nanomaterials, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China Atomically precise metal nanoclusters have made tremendous progress in recent years. [1] With molecule-like properties and tunable compositions, monodisperse metal nanoclusters have been increasingly used in catalysis, fluorescence, self-assembly and photovoltaics. [1-3] Reported t + herein is a high-nuclearity Cu cluster, [Cu53(RCOO)10(CįC Bu)20Cl2H18] (Cu53), which is the largest Cu(I)/Cu(0) cluster reported to date. As revealed by single-crystal diffraction, Cu53 is arranged as a four-concentric-shell Cu3@Cu10Cl2@Cu20@Cu20 structure. Significantly, Cu53 possesses an atomic arrangement of concentric M12 icosahedral and M20 dodecahedral shells which popularly occurs in Au/Ag nanoclusters. Surprisingly, Cu53 can be dissolved in diethyl ether and spin coated to form uniform nanoclusters film on perovskite layer which can subsequently be converted into high-quality CuI film via in-situ by iodination at room temperature. The latter proves to be a superior hole-transport layer for highly stable CuI-based perovskite solar cells (PSCs) with 14.3% of efficiency. The CuI film generating strategy provides a new and promising pathway to fabricate high-performance PSCs useful in optoelectronic devices. [1] R. Jin, C. Zeng, M. Zhou, Y. Chen, Chem. Rev. 2016, 116, 10346-10413. [2] W. Kurashige, Y. Niihori, S. Sharma, Y. Negishi, Coord. Chem. Rev. 2016, 320-321, 238-250. [3] R. S. Dhayal, W. E. van Zyl, C. W. Liu, Acc. Chem. Res. 2016, 49, 86-95. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Energy-related topics B5 Rational synthesis of transition metal oxides and the applications in energy storage systems Jiade Li1, Min Gao2, Qili Wu1, Cuiping Luo1, Jingling Yang1, Shuting Fu1, Shengfu Tong1, Mingmei Wu1 1 School of Chemistry, Sun Yat-Sen University, Guangzhou 510275, China 2 Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan Developing reliable energy storage systems is one of the most critical issues for the use of sustainable energy sources. Lithium ion batteries (LIBs) have been successfully served as power sources for high-end electronics, electric vehicles as well as hybrid electric vehicles [1]. However, the commercial LIBs with graphite anode can hardly match the requirements in large- scale energy applications due to the limited theoretical capacity and the risk of safety concern resulted from the formation of lithium dendrites. Therefore, it is necessary to explore alternative anode materials to improve the electrochemical performances, enlarge the capacity, and prolong the lifespan [2]. Transition metal oxides (TMOx) have been considered as the anode candidate that can be used in LIBs owing to the advantages, such as environmental friendly, low cost, ready to be synthesized, and safe working potential region, etc. Here, we are reporting the rationally synthesis of orientated TiO2-based materials and the potential applications in LIBs [1-3]. Besides LIBs, Li-O2 battery is another energy storage system attracted much attention both theoretically and experimentally owing to the large theoretical capacity which can be potentially used as next-generation energy storage device. One of the fatal challenges in Li-O2 batteries at current stage is the poor performances of oxygen electrode [4]. Here, the applications of TMOx in Li-O2 system also will be presented. References [1] Wu, Q. L., et al., Nano Research, 2018, 11, 2116-2128. [2] Yang, J. L., et al., ACS Appl. Mater. Interface, 2017, 9, 354-361. [3] You, H. L., et al., CrystEngComm, 2017, 19, 2456-2463. [4] Luo, C. P. et al., Chem. Commun., 2018, 54, 2858-2861. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Energy-related topics B6 Ultrasmall PtRu Nanoclusters Grown on Black Phosphorus Nanosheets as Highly Efficient Electrocatalysts for Hydrogen Evolution Reaction Jieting He1, Weihong Qi1,2*, Yejun Li3* 1 School of Materials Science and Engineering, Central South University, Changsha 410083, P. R. China 2 State Key Laboratory of Solidification Processing, Center of Advanced Lubrication and Seal Materials, Northwestern Polytechnical University, Xi’an, Shanxi 710072, P. R. China 3 Hunan Key Laboratory of Super Microstructure and Ultrafast Process, School of Physics and Electronics, Central South University, Changsha 410083, P. R. China *Corresponding author. E-mail: [email protected] (W. H. Qi); [email protected] (Y.J. Li) Black phosphorus (BP), as a novel 2D layered materials due to its novel structure and unique properties, have received great attentions in lithium ion batteries [1], thin-film solar cells [2] and photocatalysis [3]. In particularly, recent investigations have shown that BP can be used as support in electrocatalysis for enhanced hydrogen evolution activity [4,5] due to the strong synergistic effect. In this work, the PtRu nanoclusters are decorated on BP nanosheets via chemical reduction method at room temperature. TEM results indicate that the monodispersed PtRu nanoclusters with small size (around 4 nm) and good dispersion supported on BP nanosheets. The as-obtained PtRu/BP catalysts exhibit highly efficient hydrogen evolution activity in 0.1 mol L−1 KOH, where it shows an a significantly low overpotential of 46 mV vs. RHE at 10 mA /cm2, better than that of the commercial Pt/C (70mV). The present work suggests a novel strategy to construct excellent catalysts in electrocatalysis using BP as a suitable support. [1] Park CM, Sohn HJ. Black phosphorus and its composite for lithium rechargeable batteries. Adv Mater 2007;19:2465-8. [2] Dai J, Zeng XC. Bilayer phosphorence: effect of stacking order on bandgap and its potential applications in thin-film solar cells. J Phys Chem Lett 2014;5:1289-93. [3] Lee HU, Lee SC, Won J, Son BC, Choi S, Kim Y, et al. Stable semiconductor black phosphorus (BP)@titanium dioxide (TiO2) hybrid photocatalysts. Sci Rep 2015;5:8691-6. [4] Lin Y, Pan Y, Zhang J. In-situ grown of Ni2P nanoparticles on 2D black phosphorus as a novel hybrid catalyst for hydrogen evolution. Inter J Hydro Energy 2017;42;7951-56. [5] Wang J, Liu D, Huang H, Yang N. In-Plane Black Phosphorus/Dicobalt Phosphide Heterostructure for Efficient Electrocatalysis. Angew Chem Int 2018;130: 2630-34. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Optical properties and plasmonics B7 Surface plasmon enhanced photo-electrochemical current in silver nanoparticle-graphene composite nanostructures Chen Jin1, Kaiming Liao2, Ji-an Chen1, Min Han1 1 National Laboratory of Solid State Microstructures and College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093, China 2 College of Energy, Nanjing Tech University, Nanjing 210009, China The unique electronic and optical properties of graphene made it an ideal material for optoelectronic applications [1]. However, the low absorption of light and high recombination of photoelectron-hole pairs limited its application in photovoltaic devices [2]. In the present work, silver nanoparticles (AgNPs) was deposited on few-layer graphene (FLG) by gas phase cluster beam deposition method. An amperometric measurement was used for photo-electrochemical analysis. A significant current enhancement was observed and attributed to the behavior of the localized surface plasmon resonance (LSPR) of AgNPs. It was found that the wavelength and power of incident light, the density and size distribution of the AgNPs, as well as the electrode potential played important and comprehensive roles in improving the photo-electrochemical performance. The efficiency of the graphene-based photo-electrochemical system could be boost by combining graphene with plasmonic AgNPs for the reason that LSPR of AgNPs not only enhanced the absorption of light [3] but also suppressed the recombination of photoelectron-hole pairs [4]. This result paved promising ways to enhance the conversion of light into current with the AgNPs-graphene composite nanostructures, which is potentially valuable for graphene-based photovoltaic devices. Figure 1: a) Typical photocurrent response of AgNPs, FLG and AgNPs /FLG modified glass carbon electrodes (GCEs) under the same incident light (λ=405nm); b) The photocurrent response of AgNPs /FLG modified GCE under different incident light (λ= 370nm, 405nm, 450nm, 473nm, 532nm, 650nm). [1] R.R. Nair, P. Blake, A.N. et al., Science 320 (2008) 1308. [2] Q.L. Bao, K.P. Loh, ACS Nano, 6 (2012) 3677-3694. [3] Harry A. Atwater & Albert Polman, Nature Mater. , 9, 205–213 (2010). [4] Xuming Zhang, Yu Lim Chen, Ru-Shi Liu and Din Ping Tsai, Rep. Prog. Phys. 76 (2013) 046401. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Optical properties and plasmonics B8 DUV surface plasmon resonance characteristics of aluminum nanoparticle arrays Ji-an Chen1, Weifeng Luo1, Yanyue Ding1, Yunhua Chen1, Min Han1 1 National Laboratory of Solid State Microstructures and College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093, China Aluminium nanoparticles (Al NPs) are attractive for UV plasmonics because of their superior surface plasmon resonance (SPR) properties in the full UV range. Particularly, the SPR of small Al NPs fabricated by gas phase deposition locates in the deep ultraviolet (DUV) region of the optical spectrum, which can be applied to numerous fields, such as ultrasensitive organic molecule sensing and photocatalysis [1] [2]. However, for NPs prepared by various bottom-up synthetic methods, the distribution in particle size and impurities induce broadened or even featureless SPR spectra. Challenges still remain to synthesize well-controlled Al NPs suitable for DUV plasmonic applications. In the present work, dense Al NP arrays were fabricated by gas phase cluster deposition. The NP arrays exhibited intense SPR band in the UV region. The effects of size, shape, interparticle spacing as well as the thickness of the oxide layer were studied by using finite difference time domain (FDTD) method and discrete dipole approximation(DDA) method. Furthermore, we found that the broad SPR band of the dense Al NP arrays could be tuned to a sharp and strong resonance band in the DUV optical range by UV light irradiation. Figure 1: a) Experimental extinction spectrum (black) of the Al NP arrays, normalized to the bare fused silica substrate, and the calculated extinction coefficient (red) of Al NP arrays with average particle size of 20nm, coated with a 3nm oxide shell; b) Extinction spectra of the Al NP arrays recorded in real time during UV irradiation in air at room temperature. Total holding time is 140min. [1] Mcclain M J, Schlather A, Ringe E, et al. Aluminum Nanocrystals.[J]. Nano Letters, 2015, 15(4):2751-2755. [2] Knight M W, King N S, Liu L, et al. Aluminum for plasmonics.[J]. Acs Nano, 2013, 8(1):834-840. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Optical properties and plasmonics B9 Plasmon coupling and charge transfer in separate and linked jellium cluster dimers E. Selenius1, S. Malola1, M. Kuisma2, H. Häkkinen1,2 1 Department of Physics, Nanoscience Center, University of Jyväskylä, Finland 2 Department of Chemistry, Nanoscience Center, University of Jyväskylä, Finland The plasmon coupling between adjacent metal clusters can be used in many applications, for example in measuring nanoscale distances [1] and in sensing [2]. To understand the coupling of small metal clusters on the electronic level, we have studied the optical properties of separate and linked dimers consisting of jellium spheres with 8 or 138 electrons and with approximately the density of sodium. The optical spectra were calculated using linear response time-dependent density functional theory (LR-TDDFT), and the spectral peaks were further analyzed using the transition contribution map scheme [3] and by studying the induced density. The calculations were performed using the grid-based program GPAW. Fragmentation of the localized surface plasmon (LSP) peak is observed for the dimers as a result of splitting of the Kohn-Sham electron orbitals and the appearance of additional orbitals in the linking channel. In addition, several charge transfer plasmons (CTP) at energies lower than the LSP peak appear for linked dimers and separate dimers with sufficient electron cloud overlap. The simplicity of the used model systems facilitates the detailed study of electronic excitations using fully quantum mechanical calculations and thus enables better understanding of the mechanisms behind plasmon coupling and charge transfer plasmons. Figure 1: The oscillator strength distributions from the LR-TDDFT calculations for dimers with 8-electron clusters and jellium edge separations of twice the radius (A and C) and half of the radius (B and D). The width of the linking channel is the same for the two linked dimers (C and D). Oscillator strength is transferred from the LSP peak to several smaller peaks as the clusters are brought closer to each other or connected by a linking channel. [1] C. Sönnichsen, B. M. Reinhard, J. Liphardt, A. P. Alivisatos, Nat. Biotechnol. 2005, 23, 741 – 745. [2] K. A. Willets and R. P. Van Duyne, Annu. Rev. Phys. Chem. 2007, 58, 267 – 297. [3] S. Malola, L. Lehtovaara, J. Enkovaara, H. Häkkinen, ACS Nano 2013, 7, 10263 – 10270. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China 2SWLFDO SURSHUWLHV DQG SODVPRQLFV % $QDO\VLV RI HOHFWURQLF PRGHV LQ PHWDO FOXVWHUV IURP GHOWDNLFN FDOFXODWLRQV 5DMDUVKL 6LQKD5R\ 3DEOR *DUFtD *RQ]iOH] +DQV&KULVWLDQ :HLVVNHU $L[ 0DUVHLOOH 8QLYHUVLW\ &156 &,1D0 805 0DUVHLOOH )UDQFH 'HSDUWDPHQWR GH )tVLFD 7HyULFD GH OD 0DWHULD &RQGHQVDGD DQG &RQGHQVHG 0DWWHU 3K\VLFV &HQWHU ,),0$& 8QLYHUVLGDG $XWy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ptical properties and plasmonics B11 Well dispersed monoclinic VO2 nanoclusters with uniform size for sensitive near-infrared detection Lele Fan1, Lei Zhu1, Qiangqiang Meng1, Baolin Wang2,1, Qinfang Zhang1* 1Key Laboratory for Advanced Technology in Environmental Protection of Jiangsu Province, Yancheng Institute of Technology, Yancheng 224051, P. R. China 2School of Physical Science and Technology, Nanjing Normal University, Nanjing 210023, P. R. China As a typical strong correlated material, monoclinic Vanadium dioxide (VO2) has attracted broad interest due to its unique metal-insulator transition (MIT) property. While preparation for high quality monoclinic VO2 crystals with pure phase structure is not easy due to the multivalent of V atom and complex phase diagram. Furthermore, the MIT of VO2 induced phase separations or other emergent phenomena are closely associated with the grain size and boundaries within nanometer-scale range. While till now, the pure monoclinic VO2 nanoclusters with uniform grain size and high dispersion are still not achieved due to the synthesis difficulty and nanoparticles agglomeration. In the current study, we have successfully achieved the preparation of well- dispersed VO2 nanoclusters by using the unique cluster beam deposition technique. High quality and well-dispersed 3~5nm monoclinic VO2 nanoclusters can be deposited on different substrates and pronounced MIT properties are observed such as the distinct resistance change and infrared switching effect near the critical temperature. In addition, the dispersed VO2 nanoclusters demonstrated excellent infrared response and the response becomes more pronounced as decreasing the spacing of interdigital electrodes, which should be promising for sensitive near- infrared detection. Based on the photon induced electron transport framework, the IR response mechanism is discussed, which suggests the crystal grains boundaries play an important role for the performance of IR detection. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Optical properties and plasmonics B12 Characterization of Polyyne Molecules Aligned in a Stretched PVA film R. Sata1, Y. Morisawa1, H. Suzuki1, M. Hatanaka2, T. Wakabayashi1 1 Department of Chemistry, Kindai University, Japan 2 Institute of Research Initiatives and Division of Materials Science, Nara Institute of Science and Technology, Japan Sp-hybridized linear carbon molecules, when end-capped for stabilization to have alternating single and triple bonds, are called polyynes. The simplest series of hydrogen-end-capped ones, H(C≡C)nH, were proposed as interstellar molecules along the series of cyanopolyynes [1]. Spectroscopic characterization of these species in the laboratory should promote a search for them as new interstellar molecules in the future. We produced polyvinyl alcohol (PVA) films containing aligned polyyne molecules. A solution of polyyne C10H2 was prepared by laser ablation of graphite in organic solvents followed by isolation with high performance liquid chromatography (HPLC). A piece of PVA film was dipped into the solution of C10H2/methanol and stretched in one direction, by which the linear C10H2 molecules were aligned inside. In the upper panel of Figure 1, UV absorption bands of C10H2 in methanol correspond to the absorption of linearly polarized components of incident light parallel to the molecular axis [2]. In the bottom panel of Figure 1, absorption spectra of the film observed by using linearly polarized UV light show alternating absorption intensity, angle- dependent between directions of the polarization of light and the stretching of the film. Figure 1: UV absorption spectra of polyyne C10H2 in methanol (upper panel) and in the stretched PVA film (lower panel). The absorption maximum shifts from 251 nm in methanol to 260 nm in the PVA film. The absorption intensity of the film is strongest upon the polarization of incident light parallel to the direction of stretching of the film. [1] J. August, H. W. Kroto, N. Trinajstic, Astrophys. Space Sci. 128, 411 (1986). [2] T. Wakabayashi, Y. Wada, N. Iwahara, T. Sato, J. Phys.: Conf. Ser. 428, 012004 (2013). 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Optical properties and plasmonics B13 Phosphorescence of Size-Selective Polyynes at 20 K T. Wakabayashi1, K. Ozaki1, R. Sata1, H. Suzuki1, Y. Morisawa1, U. Szczepaniak2 1 Department of Chemistry, Kindai University, Japan 2 Institute of Physical Chemistry, Polish Academy of Sciences, Poland [email protected] Linear carbon chain molecules are highly reactive thus thought as reaction intermediates whose aggregates are converted to carbon nanostructures such as fullerenes, nanotubes, and graphene. Terminated by hydrogen or chemically inert moieties such as a cyano-group, the carbon chain molecules acquire intrinsic stability to be isolated in solutions at ambient temperature. We have developed a method to produce, isolate, and concentrate in solutions a series of hydrogen-end- capped molecules, namely polyynes H(C≡C)nH (n = 4-8), to characterize them by UV absorption, IR absorption [1], and resonance Raman spectroscopy [2]. Formation mechanism of 13 cyanopolyynes, H(C≡C)nC≡N (n = 3-6), was investigated by NMR spectroscopy using C isotope-enriched samples [3]. Recently, phosphorescence spectra were reported for cyanopolyynes through HC5N to HC9N in solid rare-gas matrices [4-6]. In the present work, size-separated polyynes and cyanopolyynes were co-condensed with the solvent molecules at 20 K in vacuum and subjected to phosphorescence spectroscopy. Figure 1: Phosphorescence spectrum of C8H2 in solid hexane at 20 K. Vibrational progression at 532, 603, 694, 815, and 988 nm is conspicuous for the 0-Q bands (Q = 0-4) of -1 the symmetric stretching Q2 mode of the sp-carbon chain (~2190 cm ). Inset shows 3 + 1 + phosphorescence lifetime of ~30 ms for the a 6u → X 6g transitiong of C8H2 at 20 K. [1] Y. Wada, Y. Morisawa, T. Wakabayashi, Chem. Phys. Lett. 541, 54-59, (2012). [2] T. Wakabayashi, H. Tabata, T. Doi, H. Nagayama, K. Okuda, R. Umeda, I. Hisaki, M. Sonoda, Y. Tobe, T. Minematsu, K. Hashimoto, S. Hayashi, Chem. Phys. Lett. 433, 296-300, (2007). [3] T. Wakabayashi, M. Saikawa, Y. Wada, T. Minematsu, Carbon 50, 47-56, (2012). [4] M. Turowski, C. Crépin, M. Gronowski, J.-C. Guillemin, A. Coupeaud, I. Couturier-Tamburelli, N. Pietri, R. Kołos, J. Chem. Phys. 133, 074310 (2010). [5] I. Couturier-Tamburelli, N. Piétri, C. Crépin, M. Turowski, J.-C. Guillemin, R. Kołos, J. Chem. Phys.140 (2014) 044329. [6] U. Szczepaniak, R. Kołos, M. Gronowski, M. Chevalier, J.-C. Guillemin, M. Turowski, T. Custer, C. Crépin, J. Phys. Chem. A 121, 7374 (2017). 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Optical properties and plasmonics B14 Silver-Mediated Guanine and Cytosine Duplex: Optical and Structural Properties Xi Chen 1, Esko Makkonen1 and Olga Lopez-Acevedo1,2 1 Department of Applied Physics, Aalto University, Finland 2Instituto de Física, Universidad de Antioquia, Colombia xi.6.chen@aalto,fi Silver-Mediated DNA have attracted a lot of attention because of their potential applications in biology and nanotechnology, such as nanoconductors, nanophotonics and biosensors. Structural arrangements of metal-DNA hybrid materials are particularly difficult to obtain experimentally via crystallization. The direct observation of their solution structures are even harder. Therefore, theoretical calculations using quantum chemistry methods appear as the most promising tool to propose geometries and interpret the experimental spectroscopy. I will present our recent computational studies of the atomic structures and optical properties of Ag- mediated Guanine and Cytosine homo-base duplex [1-4]. The hybrid QM (quantum mechanics)/MM (molecular mechanics), classical force field and time-dependant Density Functional Theory (TDDFT) have been used in our studies. + Figure 1: A snapshot of G2-Ag 2-G2 in water 1. The Role of Hydrogen Bonds in the Stabilization of Silver-Mediated Cytosine Tetramers. L. Espinosa Leal, A. Karpenko, S. Swasey, E. G Gwinn, V. Rojas-Cervellera, C. Rovira and O. Lopez-Acevedo, Journal of Physical Chemistry Letter 6, 4061, (2015). 2. Silver-Mediated Double Helix Structural Parameters for a Robust DNA Building Block. X. Chen, A. Karpenko and O. Lopez-Acevedo, ACS Omega 2, 7343, (2017). 3. Silver-mediated Guanine Duplex: Optical and geometrical properties. X. Chen et al. To be submitted. 4. Computing optical properties of silver stabilised DNA from molecular dynamics and Time Dependent Density Functional Theory. E. Makkonen et al. To be submitted. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Other emerging nanometer-scale systems B15 Comparison of Different Field Emitter Sources (W, MWCNT and 2D-CNT emitter) and Their Electron Emission Characteristics in Microcolumn Anjli Sharma1, 2, Sanjeev K. Kanth2, Dae_Wook Kim2, Seung Joon Ahn2, Ho Seob Kim2, Qinfang Zhang1* 1 Department of material science and engineering, Yancheng Institution of Technology, China 2 Department of Information Display, Sun Moon University, South Korea [email protected] Miniaturized low voltage electron beam devices have been widely used for the metrology, inspection, lithography and for the semiconductor display devices. The electron optical microcolumn is a potential candidate for the low voltage operation of scanning electron microscope. The compact size of microcolumn allows it to be assembled into an arrayed electron beam source. In a microcolumn, a sharp tungsten field emitter is usually used as an electron emitter fabricated through electrochemical etching process [1]. In case of MWCNT emitter, MWCNT is attached onto the tungsten support tip using the nanomanipulator in SEM [2]. However, the alignment process of tungsten tip and MWCNT tip with the extractor aperture is a challenging and time consuming task in the assembly of a microcolumn. On the other hand, the two dimensionally distributed CNT (2D-CNT) [3] field emitter alignment on the extractor aperture is easy as it cover the entire extractor aperture diameter. Thus, we have considered tungsten tip, MWCNT tip and 2D-CNT tip as electron sources and compared their electron emission characteristics in a microcolumn by assembling test columns. Figure 1: Field emitter source: (a) electrochemical etched tungsten tip (tip radius ~100nm), (b) MWCNT field emitter (length of the FIB- milled region is ~ 3-5 µm) and, (c) 2D-CNT emitter on the Kovar wire surface. [1] H. S. Kim, M. L. Yu, U. Staufer, L. P. Muray, D. P. Kern, and T. H. P. Chang, J. Vac. Sci. Technol. B 11, 2327 (1993). [2] S. K. Kanth, A. Sharma, B. C. Park, and H. S. Kim, J. Vac. Sci. Technol. B 34, 011805 (2016). [3] J. W. Jeong, J. W. Kim, J. T. Kang, S. Y. Choi, S. J. Ahn, and Y. H. Song, Nanotechnology 24, 085201 (2013). 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Other emerging nanometer-scale systems B16 Bright luminescence of Ag-LTA-zeolites originating from long-lived triplet state of two- electron super-atom quantum systems confined in Ag4(H2O)2 and Ag4(H2O)4 clusters Didier Grandjean1, Eduardo Coutino-Gonzalez2, Ngo Tuan Cuong3,4, Eduard Fron2, Wouter Baekelant2, Saleh Aghakhani1, Philomena Schlexer8, Francesco D’Acapito6, Dipanjan Banerjee7, Maarten B.J. Roeffaers5, Minh Tho Nguyen4, Johan Hofkens2, Peter Lievens1 1Laboratory of Solid State Physics and Magnetism, KU Leuven, Belgium, 2Molecular Visualization and Photonics, KU Leuven, Belgium, 3Faculty of Chemistry, Hanoi National University of Education, Vietnam, 4Department of Chemistry, KU Leuven, Belgium, 5Centre for Surface Chemistry and Catalysis, KU Leuven, Belgium, 6CNR-IOM-OGG c/o ESRF LISA CRG Grenoble, France, 7Dutch-Belgian beamline, ESRF - The European Synchrotron, France, 8Dipartimento di Scienza dei Materiali, Università di Milano-Bicocca, Italy. [email protected] The nanometer sized sodalite cages of zeolites are ideally suited for incorporating small metal clusters and for creating large scale assemblies of uniform clusters with properties that can be tuned by the type of zeolite matrix, the amount of metal loading, and the chemical environment of the metal cluster. The luminescence properties of small silver clusters confined in zeolite matrices are remarkable, with quantum efficiencies close to 100% attained in some specific cases [1]. Nevertheless, detailed knowledge about the structural and electronic properties is often lacking. Here we report on a detailed study of the bright green luminescence of four Ag atom clusters confined in partially exchanged Ag-LTA-zeolites [2]. We combine X-ray Excited Optical Luminescence-Extended X-ray Absorption Fine Structure (XEOL-EXAFS), Time Dependent- Density Functional Theory (TD-DFT) calculations, and time-resolved spectroscopy to elucidate the mechanisms responsible for the peculiar optical properties. The combined analysis identifies positively charged tetrahedral silver tetramer clusters ligated with two or four water molecules, occupying the center of a fraction of the sodalite cages. Their optical properties originate from a confined two-electron super-atom quantum system with hybridized Ag and water O orbitals delocalized over the cluster. Upon excitation, one electron of the s-type highest occupied molecular orbital (HOMO) is promoted to the p-type lowest unoccupied molecular orbitals (LUMOs) and relaxes through enhanced system intercrossing into long-lived triplet states. The unique combination of XEOL detected structural analysis pinpointing the active optical Ag species, with time resolved spectroscopy and a DFT study is providing a major step forward in the understanding of this type of metal cluster species. A significant impact of these new results is expected in future developments of few-atom clusters in the field of photonics but also in catalysis and magnetism. [1] O. Fenwick, E. Coutiño-Gonzalez, D. Grandjean, W. Baekelants, F. Richard, S. Bonacchi, D. De Vos, P. Lievens, M. Roeffaers, J. Hofkens, P. Samori, Nature Materials 15, 1017 (2016). [2] D. Grandjean, E. Coutiño-Gonzalez, Ngo Tuan Cuong, E. Fron, W. Baekelant, S. Aghakhani, Ph. Schlexer, F. D’Acapito, D. Banerjee, M.B.J. Roeffaers, Minh Tho Nguyen, J. Hofkens, P. Lievens, Science, in press (2018). 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Other emerging nanometer-scale systems B17 Hydrogen Terminated Phosphorene Nanoflakes: thermal stability, flexibility and implications for singlet oxygen generation Tibor Höltzl1,2, Dorina Bódi2 1Furukawa Electric Institute of Technology, Késmárk utca 28/A, H-1158 Budapest, Hungary 2Budapest University of Technology and Economics, H-1521 Budapest, Hungary Formal cut of lower dimensional structures from 2D phosphorene layers is one of the most promising ways to tune their properties.[1] Recently, nanoflakes attracted considerable attention among the lower dimensional phosphorene-based nanostructures as, their tunable properties (e.g. size-dependent band gap) induce a wide range of possible applications, like solar cells[2] or photocatalytic water splitting[3]. While stability and flexibility of phosphorene nanoflakes is crucial for several applications, there is only limited information available. We present the flexibility and stability of hydrogen terminated phosphorene nanoflakes with diameters ranging from the molecular size (0.2-0.6 nm) to nano-size (1-2 nm) using quantum chemical computations, ab-initio molecular dynamics as well as using the External Force is Explicitly Included (EFEI) method. Our computations [4] showed that while the flexibility of hydrogen terminated phosphorene nanoflakes depends on their geometry, they keep their quasi-planar structure up to at least 500K, while at more elevated temperatures they distort and decompose. Hydrogen terminated phosphorene nanoflakes are energetically more stable than the white phosphorus, however the investigation of the gas phase free energies showed the opposite trend. In the gas phase the temperature and the pressure have great effects on the stability of phosphorene nanoflakes. Our computations showed that during gas phase synthesis from phosphine the formation of white phosphorus is preferred due to the change of the entropy. This highlights the importance of the precursor for the gas phase synthesis. Larger phosphorene nanoflakes may also be synthesized in the gas phase from phosphine. Also, the solvation computations showed that in the liquid phase the formation of phosphorene nanoflakes is preferred. The singlet oxygen generation of phosphorene was shown recently [5]. We also present our new computational results for the triplet state and its connection to the singlet oxygen generation. Fig.1 Title of the figure. [1] H. Guo et al. J Phys. Chem. C 118, 1405–14059 (2014) [2] W. Hu et al. Nano Lett. 16, 1675–1682 (2016). [3] S. Zhou, N. Liu N. J. Zhao Compt. Mat. Sci. 130, 56–63 (2017). [4] D. Bódi, T. Höltzl J. Phys. Chem. C (2018). [5] H. Wang, et al. J. Am. Chem. Soc. 137, 11376-11382 (2015). 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Reactivity and catalysis B18 Identifying Synergistic Interaction between Copper Tetramers and Iron Oxide towards Highly-active Methanol Synthesis from CO2 Bing Yang1, Xiaoben Zhang1, Dangsheng Su1, Xin Yu2, Soenke Seifert4, Stefan Vajda3 1 Dalian National Laboratory for Clean Energy (DNL), Dalian Institute of Chemical Physics, Chinese Academy of Sciences, P. R. China 2 National Energy Center for Coal to Clean Fuels, Synfuels China Co., Ltd., P. R. China 3Material Science Division and 4X-ray Science Division, Argonne National Laboratory, USA [email protected] Atomically precise subnanometer catalysts, including single atoms, dimers and multimeric clusters, have recently attracted tremendous interests due to their specific activity and remarkable efficiency in a variety of catalytic reactions. Among a wide range of synthetic methods, soft-landing of mass-selected clusters is a unique technique with both with atomic precision and high tenability, to produce catalyst clusters with precise number of atoms. Previously, we have soft-landed size-selected Cun clusters on alumina and described their cluster size effect in catalytic CO2 reduction.[1-4] Beyond cluster size, metal-support interaction is another substantial factor particularly in sub- nanometer catalysts, to stabilize ultra-small clusters and further tune their catalytic properties. In this talk, I will cover our latest study of copper tetramers (Cu4) supported on variable-valence Fe2O3 for highly active CO2 hydrogenation. Our results revealed that atomically precise Cu4/Fe2O3 catalysts possess strikingly high activity for methanol production at atmospheric pressure with turn-over rate (TOR) of 1.1-1.2h10-3 s-1 atom, -1, which is among the highest reported value from literatures. Operando studies and in-situ X- ray characterizations were conducted to identify the active sites and metal-support interaction under in-situ reaction conditions. A synergistic interaction between copper tetramers and iron oxide was verified. Cu4 tetramers facilitate the H2 splitting and spillover to reduce iron oxides at the 2+ neighboring sites, yielding surface-rich Fe species, which in return promotes CO2 activation resulting in HCOO* intermediates and enhanced methanol activity. The identification of highly active Cu4-FeOx also benefits the general design and optimization of copper catalyst towards efficient CO2 conversion. Figure 1: Left) Reactivity of Cu4/Fe2O3 for CO2 hydrogenation monitored by online mass spectrometer. Production rate of CH3OH(m/z 31), CH4 (m/z 15) and C3H6 (m/z 41) with increasing reaction temperature; Right) Synergistic effect between Cu4 and Fe2O3 and the proposed reaction route of CO2 hydrogenation for enhanced methanol production. [1] Yang, B.; Liu, C.; Halder, A.; Tyo, E. C.; Martinson, A. B. F.; Seifer, S.; Zapol, P.; Curtiss, L. A.; Vajda, S., Copper Cluster Size Effect in Methanol Synthesis from CO2. J. Phys. Chem. C 2017, 121 (19), 10406-10412 [2] Liu, C.; Yang, B.; Tyo, E.; Seifert, S.; DeBartolo, J.; von Issendorff, B.; Zapol, P.; Vajda, S.; Curtiss, L. A., Carbon Dioxide Conversion to Methanol over Size-Selected Cu-4 Clusters at Low Pressures. J. Am.Chem. Soc. 2015, 137 (27), 8676-8679 [3] Mammen, N.; Spanu, L.; Tyo, E. C.; Yang, B.; Halder, A.; Seifert, S.; Pellin, M. J.; Vajda, S.; Narasimhan, S., Reversing Size-Dependent Trends in the Oxidation of Copper Clusters through Support Effects. Eur. J. Inorg. Chem. 2018, (1), 16-22. [4] R. Passalacqua, S. Parathoner, G. Centi, A. Halder, E. C. Tyo, B. Yang, S. Seifert, S. Vajda. Electrochemical behaviour of naked sub-nanometre sized copper clusters and effect of CO2. Catal. Sci. Tech. 2016, 6, 6977-6985. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Reactivity and catalysis B19 Decoration of carbon quantum dots onto TiO2 nanoparticles for visible-light photocatalytic reduction of Cr(VI) D. Choi, S. Ham, D.-J. Jang* Department of Chemistry, Seoul National University, Republic of Korea Effective removal of hazardous contaminants is the key issue for recycling of wastewater. Among those contaminants, hexavalent chromium Cr(VI) is especially hazardous to public health due to its carcinogenic properties and great mobility. Photocatalysis is a highly attractive and environment-friendly approach [1] for practical removal of Cr(VI) by utilizing sunlight to convert Cr(VI) into less toxic trivalent chromium Cr(III), which can be precipitated out of solutions in the form of Cr(OH)3. Here, we suggest a dyade structure of carbon quantum dots (CQDs)-decorated TiO2 (C/TiO2) nanocomposites via a simple hydrothermal method without any other chemical linkers. Direct contact between CQDs and TiO2 is beneficial to charge transfer in the nanocomposite system, and the photocatalytic activity of C/TiO2 nanocomposites under visible light has been found to be much higher than that of TiO2 nanoparticles, suggesting that our C/TiO2 nanocomposites are applicable as photocatalysts in the field of Cr(VI) elimination. CQDs were synthesized via a hydrothermal method employing citric acid as the precursor [2]. Prepared CQDs were incorporated onto commercial P25 TiO2 nanoparticles via a hydrothermal method. In this processes, the decoration of CQDs was conducted with different weight percentages of CQDs of 1, 2, 3 and 4% of TiO2 nanoparticles, respectively. The photocatalytic reduction activity of C/TiO2 nanocomposites were evaluated by measuring the photoreduction of Cr(VI) under visible-light irradiation, using Xe lamp and 420+ nm cutoff filter; the light irradiance was 170-200 mW cm-2. As-prepared CQDs have spherical structures with diameters of 5-10 nm and are uniformly dispersive in water. With various dosages of CQDs, C/TiO2 nanocomposites were synthesized by a hydrothermal method and characterized by measuring EDX elemental maps. The photocatalytic reduction of Cr(VI) under visible-light were monitored at ambient conditions to evaluate the photocatalytic activities of C/TiO2 nanocomposites. To exclude the effects of holes generated, excess sodium sulfite was added as a sacrificial agent, hindering the electron-hole recombination and oxidization of Cr(III). Whereas the concentration of Cr(VI) was hardly decreased without catalysts or in the dark, C/TiO2 nanocomposites showed up to 8.6 times greater photocatalytic activities than that of pure TiO2 nanoparticles under visible light. These superior photocatalytic activities originate from the excitation mechanism of C/TiO2 nanocomposites under visible light. When CQDs are irradiated by visible light, photo-generated electrons transfer from CQDs into the conduction band of TiO2. Transferred electrons are subsequently captured by Cr(VI) ions, reducing Cr(VI) ions into Cr(III). This suggested mechanism is supported by the emission spectra and photoluminescence decay profile of C/TiO2 nanocomposites. [1] J. Lee, Y. Kim, J. K. Kim, S. Kim, D.-H. Min, D.-J. Jang, Appl. Catal. B: Environ. 2017, 205, 433-442. [2] D. Choi, S. Ham, D.-J. Jang, J. Environ. Chem. Eng. 2018, 6, 1-8. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Reactivity and catalysis B20 Synthesis of Pd@PtNi core-shell nanoparticles with precisely controlled shell-layer composition for electrochemical catalysis Yafeng Zhang1, Wenjing Mao1, Fengqi Song2, Feng Yin1* (1 Laboratory of Low Dimensional Condensed Matter Physics, Shaanxi Normal University, Xi'an 710119, China) (2 National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093, China) *E-mail: [email protected] The design and synthesis of Pt-based nanocatalyst has been attracted great attention, mainly due to the structural diversity and the highly active catalytic properties for fuel cells as well as various chemical reactions. Generally, optimizing the utilization efficiency and stability of Pt-based nanocatalysts through adjusting the nanostructure or composition [1,2]. In this work, we combine the benefits of these two ways and demonstrate an effective synthetic approach to prepare a promising kind of Pd@PtNi core@shell nanocrystal with precisely controlled shell-layer composition. TEM images show that the nanoparticles have uniform size at around 14nm and the Pt (111) planes dominate the surface. The composition of the alloy shell can be well controlled by simply controlling the reaction time. ICP- AES results show the Pt/Ni atomic ratio reduces from ~2.1 to ~1.2, as reaction time increases from 1 hour to 7 hours. The platinum mass activity is 7.6 and 4.4 folds towards the ORR and MOR in comparison with commercial Pt/C catalyst, respectively. (a) (b) 1.2 (c) 1.2 (d) 1.5 1.8 ORR MOR y=2.1 1.5 1.8 y=2.1 Pt/C Pt/C Fig. 1 (a) LRTEM image of NPs. (b) HRTEM image of NP. (c) Comparison of jk,mass and jk,specific between Pd@PtyNi/C catalysts and commercial Pt/C catalyst for ORR. (d) Comparison of jk,mass between Pd@PtyNi/C catalysts and commercial Pt/C catalyst for MOR. y represents the atomic Pt/Ni ratio on the NPs surface. Reference: [1] Huang X, et al. Science 348, 1230-1234 (2015). [2] Bu L, et al. Science 354, 1410-1414 (2016). Acknowledgement: This work was supported by National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093, China (M28029). 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Reactivity and catalysis B21 Hydrogen Evolution Reaction by Size-selected Platinum Nanoclusters Supported on Strontium Titanate H. Tsunoyama1, M. Komori1, T. Eguchi2, A. Nakajima1,3 1 Department of Chemistry, Faculty of Science and Technology, Keio University, Japan 2 Department of Physics, Graduate School of Science, Tohoku University, Japan 3 Keio Institute of Pure and Applied Sciences (KiPAS), Keio University, Japan [email protected] Metal nanoclusters (NCs) have been promising candidates for novel catalysts based on their size-specific chemical properties, which are remarkably different from their bulk materials. In order to elucidate their size-dependent catalytic activities, soft-landing method for size- selected NCs on the well-defined surfaces have been developed and utilized for catalysis researches under high vacuum conditions [1-5]. To bridge the gap between well-defined model systems [1-5] and real-world catalysts, we have studied catalytic activity of size-selected metal NCs under ambient atmosphere in liquid phase by utilizing an intensive size-selected NC ion source of nanojima® [6]. We have reported herein catalytic activity of size-selected platinum (Pt) NCs supported on strontium titanate (SrTiO3) for electrocatalytic hydrogen evolution reaction (HER) in aqueous solution [7]. Size-specific activity of Pt NCs are discussed based on their electronic structures. Single-size Pt NC catalysts (Ptn/SrTiO3) were prepared by soft-landing of size-selected Pt – NCs (Ptn ) to SrTiO3(100) substrate. It is noteworthy that maximum ion current for Pt NC 11 – anions reaches as high as 20 nA (= 1.2 u 10 NCs/sec) for Pt7 , which corresponds to deposition rate of 0.1 monolayer/min for 1 cm2 substrate. Catalytic activity for HER was examined by electrochemical measurements using a three-electrode electrochemical cell with 0.1 mol/L sodium sulfate aqueous solution under argon atmosphere, where Ag/AgCl reference and Pt wire counter electrodes were used. Electronic structures of Pt NCs were examined by gas-phase anion photoelectron spectroscopy (PES) for size-selected NCs. Morphology for Ptn/SrTiO3 was elucidated by scanning tunneling microscopy (STM). Based on STM images, Pt NCs were homogeneously dispersed on the SrTiO3 surface, where no preferential adsorption on edges of step-and-terrace structure was found. Appearance potential (Vap) for HER anodic current shifts to positive for Pt-NC deposited electrodes from a bare SrTiO3, which indicates that Pt NCs work as active sites. It was found from the Vap values for Ptn/SrTiO3 that catalytic HER activity per unit Pt shows a maximum at Pt30 among n = 1, 15, 30, and 45. Taking into account the electron affinities of free Pt NCs, the reaction mechanism of HER is deduced: the size-specific HER activity originates from the matching of energy levels of the lowest unoccupied molecular orbitals of Pt NCs with the band structure of SrTiO3 surfaces. References [1] A. Sanchez, S. Abbet, U. Heiz, W.-D. Schneider, H. Häkkinen, R. N. Barnett and U. Landman, J. Phys. Chem. A 103, 9573 (1999). [2] R. E. Palmer, S. Pratontep and H.-G. Boyen, Nature Mater. 2, 443 (2003). [3] W. E. Kaden,T. Wu, W. A. Kunkel and S. L. Anderson, Science 326, 826 (2009). [4] A. Nakajima, Bull. Chem. Soc. Jpn. 86, 414 (2013). [5] E. C. Tyo and S. Vajda, Nat. Nanotechnol. 10, 577 (2015). [6] H. Tsunoyama, C. Zhang, H. Akatsuka, H. Sekiya, T. Nagase and A. Nakajima, Chem. Lett. 42, 857 (2013). [7] H. Tsunoyama, Y. Yamano, C. Zhang, M. Komori, T. Eguchi and A. Nakajima, Top. Catal. 61, 126 (2018). 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Reactivity and catalysis B22 Hydrogen chemisorption on rhodium doped aluminum clusters Jan Vanbuel1,MeiyeJia1,PieroFerrari1, Sandy Gewinner2, Wieland Schöllkopf2,Minh Nguyen3, André Fielicke2, Ewald Janssens1 1 Laboratory of Solid State Physics and Magnetism, KU Leuven, Belgium 2 Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin, Germany 3 Department of Chemistry, KU Leuven, Belgium [email protected] Hydrogen is a clean and sustainable alternative to the use of fossil fuels for our energy supply. Despite having a high gravimetric energy density, the volumetric density of hydrogen is too low to be of practical use. Solid state storage of hydrogen in metal hydrides such as NaAlH4 increases the volumetric density but often suffers from slow (de)hydrogenation kinetics or irreversibility. The study of clusters in the gas phase allows for a detailed understanding of the thermodynamics and kinetics at play and could aid in the development of improved hydrogen storage materials. + We investigated the interaction of hydrogen with AlnRh2 (n = 10–13) clusters by mass spectrometry and infrared multiple photon dissociation (IRMPD) spectroscopy performed at the FEL facility of the Fritz-Haber-Institut [1,2]. Comparing the IRMPD spectra with predictions obtained using density functional theory calculations allows for the identification of the hydrogen binding geometry. We observed a competition between molecular and dissociative adsorption: for n = 10 and 11, a single H2 molecule binds dissociatively, whereas for n =12and + 13, it adsorbs molecularly. Upon adsorption of a second H2 to Al12Rh2 , at least one of the hydrogen molecules dissociates and spills over to the aluminum. Theoretical calculations suggest that the molecular adsorption is not due to kinetic impediment of the hydrogenation reaction by an activation barrier, but due to a higher binding energy of the molecularly adsorbed hydrogen–cluster complex. + -1 Figure 1: IRMPD spectra of Al12Rh2H2m (m =1,2).Form = 1, he bands at 800 cm and 1600 -1 cm correspond to molecularly bound H2-M vibrational modes. For m = 2, only bands at 1900 cm-1 are observed, corresponding to dissociatively adsorbed hydrogen. [1] J. Vanbuel, M. Jia, P. Ferrari, S. Gewinner, W. Schöllkopf, M. T. Nguyen, A. Fielicke, E. Janssens, Top. Catal. 2017, DOI 10.1007/s11244-017-0878-x. [2] W. Schöllkopf, S. Gewinner, H. Junkes, A. Paarmann, G. von Helden, H. Bluem, A. M. M. Todd, Proc. SPIE 2015, 9512, 95121L. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Reactivity and catalysis B23 Structure determination of cationic Cu and Ni clusters through far-IR spectroscopy Joost. M. Bakker1, O. Lushchikova1, S. Nooteboom1, D.J.J. Huitema1, P. López- Tarifa2, Z. Jamshidi2, & L. Visscher2 1 Radboud University, FELIX Laboratory, Nijmegen, the Netherlands 2 VU Free University Amsterdam, the Netherlands The catalytic recycling of CO2 to liquid fuels, such as methanol, may help to control the atmospheric CO2 content and thereby reduce climate change and its concurring societal impact. The synthesis of methanol from CO2 and hydrogen is exothermic, but inefficient due to a large activation barrier. The industrial process for this reaction is a ternary Cu/ZnO/Al2O3 catalyst, but its reaction mechanism is under debate [1–3]. A broad range of experimental and theoretical studies suggest that the most active parts are formed by Cu in nanoparticle form, but its reaction mechanism is not well understood. Reactivity studies over extended Cu surfaces identified that Ni acts as a promotor [4], but the exact role of Ni in this process is unclear. Recently, a novel hydrogenation catalyst based on a Ni:Ga alloy was proposed [5] To understand what role Cu and Ni can play in activating CO2, we intend to study elementary reaction steps of CO2 hydrogenation on Ni and Cu clusters. The combination of far-IR action spectroscopy with mass spectrometry and quantum chemical calculations allows to quantify and to distinguish the catalytic effects of individual sites. As a prerequisite for this, the structure of Cu and Ni clusters needs to be established, so that the activation reaction path can be understood. In 2008, Fielicke and co-workers established that H2 adsorbed molecularly onto cationic Ni clusters [6], but no structures of the bare Ni clusters themselves are known. We here present IR spectra of Ni and Cu clusters, through IR photodissociation spectroscopy of their complexes with Ar. The structures are assigned based on the comparison of measured IR- spectra in 70-300 cm-1 spectral range with DFT and Born-Oppenheimer Molecular Dynamics calculations. [1] L. C. Grabow and M. Mavrikakis, ACS Catal. 1, 365 (2011). [2] F. Studt, M. Behrens, E. L. Kunkes, N. Thomas, S. Zander, A. Tarasov, J. Schumann, E. Frei, J. B. Varley, F. Abild-Pedersen, J. K. Norskov, and R. Schlögl, ChemCatChem 7, 1105 (2015). [3] S. Kattel, P. J. Ramírez, J. G. Chen, J. A. Rodriguez, and P. Liu, Science 355, 1296 (2017). [4] P. Liu, Y. Yang, and M. G. White, Surf. Sci. Rep. 68, 233 (2013). [5] F. Studt, I. Sharafutdinov, F. Abild-Pedersen, C. F. Elkjær, J. S. Hummelshøj, S. Dahl, I. Chorkendorff, and J. K. Nørskov, Nat. Chem. 6, 320 (2014). [6] I. Swart, P. Gruene, A. Fielicke, G. Meijer, B. M. Weckhuysen, and F. M. F. de Groot, Phys. Chem. Chem. Phys. 10, 5743 (2008). 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Reactivity and catalysis B24 Chemical bonding of propene on bare and yttrium doped gold clusters J. Barabás1, J. Vanbuel2, P. Ferrari2, E. Janssens*2, T. Höltzl*1,3 1 Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Hungary 2 Laboratory of Solid State Physics and Magnetism, KU Leuven, Belgium 3 Furukawa Electric Institute of Technology, Hungary During the past decades small metal clusters have become an interesting research topic, because their physical and chemical properties are significantly different from those of the corresponding bulk material. One of the main advantages is their improved catalytic performance, which is sensitive to the particle size, since the surface structure and electronic properties substantially change in this size range [1]. The catalytic activity of gold nanoclusters has attracted considerable attention due to potential applications. Recently, the gas phase reactions between neutral Aun (n = 9-25) clusters with propene under few collision conditions demonstrated that the reaction probability for propene adsorption is larger for gold clusters composed of an even number of atoms [2]. In this contribution, the adsorption of propene on bare and yttrium doped gold clusters (n=5- 15) was studied by a combination of mass spectrometry and density functional theory calculations. The results show that the stability of the complexes and the reactivity of the clusters depends strongly on the cluster size and the presence of yttrium dopant. By the analysis of structures of the cluster-propene complexes, we observed that propene connects to the yttrium atom in the doped clusters if the structure is two-dimensional, but connects to a gold atom for larger clusters, in which the yttrium atom is less accessible. Furthermore, propene binds preferentially on-top a low coordinated gold atom through its C- C double bond. The preferred propene adsorption site is determined by the LUMO orbital of the bare cluster: propene prefers to bind to that atom where the LUMO has the largest lobe. Using energy decomposition analysis a clear correlation between the intermolecular binding energy and the adsorption energy was found, showing that intermolecular binding and non- covalent interactions are important during the adsorption. For the mechanism of the adsorption, the analysis of chemical bonding and orbitals implied a donation/back-donation mechanism. If propene binds to a gold atom, two main occupied- virtual orbital pairs participate in donation-back donation, while for smaller yttrium doped clusters more occupied-virtual orbital pairs exist, and the yttrium atom also participates in the back-donation. [1] P. Serp, K. Philippot; Nanomaterials in Catalysis, Wiley-VCH Verlag GmbH & Co. KgaA, 2013. [2] E. Janssens, H. T. Le, P. Lievens, Adsorption of propene on neutral gold clusters in the gas phase, Chem. Eur. J 21, 2015, 15256. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Reactivity and catalysis B25 Theoretical study of the adsorption of hydrogen on cobalt clusters J. A. Alonso1, K. García-Diez1, J. Fernández-Fernández1, M. J. López1 1 Departamento de Física Teórica, Atómica y Optica, University of Valladolid, Spain The interaction of hydrogen with metal clusters and nanoparticles plays an important role in several technological fields. Porous carbons are being investigated as possible hydrogen containers, and experimental work indicates that doping with metal clusters and nanoparticles enhances the storage capacity of the porous carbons. The interaction between hydrogen and transition metal clusters is also relevant in the operation of the hydrogen fuel cells. Transition metal clusters embedded in the anode of the fuel cell catalyze the dissociation of molecular hydrogen in protons and electrons, which recombine with oxygen at the cathode of the fuel cell. Hydrogen chemisorption on the surface of transition metals is a process of interest in catalysis. A number of transition metal surfaces and nanoparticles catalyze hydrogenation reactions, and these reactions require the presence of adsorbed hydrogen. Clusters of the 3d transition metals, because of their lower mass compared to 4d metals, can be of interest for the applications mentioned above, and we focus attention on cobalt. To investigate the possibility of widening the applications of cobalt clusters and nanoparticles, their interaction with hydrogen has to be studied. Previous works have not investigated the saturation coverage limit for hydrogen adsorption on Co clusters. We use the density functional theory to investigate the interaction of hydrogen with two cobalt clusters, Co6 and Co13. Molecular adsorption and dissociative adsorption of one and two hydrogen molecules on these clusters are first studied. Adsorption energies, electronic charge redistribution on adsorption, and the spin magnetic moments are discussed as well as the effect of the cluster size. Then, adsorption of additional hydrogen is investigated in the case of the smaller cluster, Co6, and the competition between molecular and dissociative adsorption is analyzed as the number of adsorbed H2 molecules increases. Saturation is obtained with 16 H2 molecules. In this saturation limit the weight per cent of hydrogen on the cluster is 8.4 per cent. Figure 1: Structure of Co6 with eight H atoms and an H2 molecule adsorbed (left), and with eight H atoms and two H2 molecules adsorbed (right). 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Reactivity and catalysis B26 Enatioselective reduction of levulinic acid on ligand-modified Pt nanoparticles L. Gell1, K. Honkala1 1 Department of Chemistry, University of Jyväskylä, Finland Organometallic compounds are extensively used in homogeneous catalysis. The importance of the ligand molecule for the stability of the catalyst, the reaction rate and the selectivity have been widely studied[1]. In heterogeneous catalysis however, the possibility for beneficial use of organic ligands has only recently become of interest[2,3]. In this work, we aim to design sulfur free ligands which will form self-assembled pockets on platinum nanoparticles to tailor enantioselectivity for ketone reduction reactions. We have employed density functional theory to describe the interaction between the ligands and a Pt(111) surface that mimics a facet of a nanoparticle. By choosing ligands which can easily form directed intermolecular hydrogen bonds, it is possible to obtain energetically favored structures of two or more self assembled ligands. The obtained pocket favors a heterolytic H2 splitting and allows only limited access for the reactant to the reaction side, thus increasing the likelihood of an enantioselective reduction. Figure 1: Platinum nanoparticle covered by self-assembling ligand molecules forming pockets for enantioselctive reductions. [1] Sawamura, M. et al.; Chem. Rev. 1992, 92, 857 [2] Mallat, T. et al.; Chem. Rev., 2007, 107 , 4863 [3] Marshall, S. T. et al.; Nat. Mater. 2010, 9, 853 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Reactivity and catalysis B27 + Infrared Photodissociation Spectroscopy of Cluster Complexes Com Hen Low-lying Electronic States and Reactivity of Cobalt Cluster Ions Masahiko Ichihashi1, Hideho Odaka2 1 Cluster Research Laboratory, Toyota Technological Institute, Japan 2 East Tokyo Laboratory, Genesis Research Institute, Inc., Japan [email protected] Reactions of molecules adsorbed on metal clusters have been considered as a fundamental model of catalysts, and attracted much interest both in basic science and industrial areas. In order to examine the reaction mechanisms, it is indispensable to elucidate their geometric and electronic structures. Infrared spectra of the nanocatalyst in a helium cluster give much information on the structures. Recently we have developed a technique to form cluster complexes by use of low- energy collision between clusters. This technique can provide significant amount of cluster complexes of helium clusters having metal cluster ions, and we demonstrate the formation of the cluster complexes including cobalt cluster ions and the spectroscopy. Low-energy collision experiments were performed by using a merging-beam apparatus [1,2] as + + ؆ 30000), Com Hen wereۄNۃ) shown in Fig. 1. In the collision between Com (m = 1−7) and HeN + observed, and it was found that the total intensity of Com Hen is inversely proportional to the + relative velocity between Com and HeN, though it levels off in a slightly high velocity region, and steeply decreases above 103 m/s. This profile suggests that the main interaction changes from the charge-induced dipole one to the hard-sphere type one with the increase of the relative + velocity. At the higher velocities, Com which collided with the periphery of HeN cannot stop at the inside of HeN and passes through it. + -1 Photodissociation spectra of Com Hen were measured in the wavenumber range of 5000−7000 cm . + + We found that Co6 Hen have relatively large intensity of the photofragment, Co6 . This dissociation + comes from the electronic excitation of Co6 , + and suggests that Co6 has an electronic transition in this low-energy (0.65−0.85eV) region. The computational results of the time-dependent density functional theory (TDDFT) confirm this interpretation. These low-energy electronic excitations should be related with the reactivity of the clusters, and a typical example is shown in the reaction of + Com with NO. [1] H. Odaka, M. Ichihashi, RSC Adv. 5, 78247 (2015). Figure 1: Schematic drawing of the apparatus employed. [2] H. Odaka, M. Ichihashi, Eur. Phys. J. D 71, 99 (2017). 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Reactivity and catalysis B28 Water oxidation reaction with manganese oxide clusters N. T. Zimmermann, S. M. Lang, T. M. Bernhardt University of Ulm, Institute of Surface Chemistry and Catalysis, Germany [email protected] One of the fundamental biological reactions, the catalytically activated water-splitting, takes place at an inorganic mono-calcium tetra-manganese penta-oxygen (CaMn4O5) cluster. To probe fundamental concepts of the water splitting reaction and to aid the design of artificial water- splitting molecular catalysts we prepare free manganese-oxide clusters as well-defined model systems and study their reactivity in an ion trap experiment. Recent studies from our + laboratory mainly focused on the stoichiometric Mn4O4 cluster. Reactivity experiments in conjunction with infrared-vibrational spectroscopy have demonstrated that this tetra- manganese-tetra-oxygen cluster adsorbs multiple water molecules and deprotonates water by hydroxylation of the oxo- bridges of the cluster. [1-4] To improve the reactive properties of manganese-oxide clusters and to potentially enable the oxidation of water we have now extended our studies to non-stoichiometric clusters. In particular, clusters with an increased formal oxidation state of the manganese atoms are expected to show improved properties as an oxidizing catalytic agent for water. [5] Therefore, + we focused our investigations on the reactivity of oxygen-rich species MnxOy (x < y) towards D2O and H2O. Figure 1: Mass spectra of manganese oxide clusters without (a) and with (b) additional O2 gas in the target chamber. [1] S. M. Lang, T. M. Bernhardt, D. M. Kiawi, J. M. Bakker, R. N. Barnett, U. Landman, Phys.Chem.Chem.Phys., 2016, 18, 15727 [2] S. M. Lang, I. Fleischer, T. M. Bernhardt, R. N. Barnett, U. Landman , J. Phys. Chem. C, 2015, 119, 10881−10887 [3] S. M. Lang, I. Fleischer, T. M. Bernhardt, R. N. Barnett, U. Landman, Nano Lett., 2013, 13, 5549−5555 [4] S. M. Lang, T.M. Bernhardt, D. M. Kiawi, J. M. Bakker, R. N. Barnett, U. Landman, Angew. Chem. Int. Ed., 2015, 54, 15113–15117 [5] N. Cox, J. Messinger, Biochimica et Biophysica Acta, 2013, 1827, 102–1030 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Reactivity and catalysis B29 Preparation of binary ruthenium-siliconoxide-clusters for CO-methanation P. Walter, S. M. Lang, T. M. Bernhardt University of Ulm, Institute of Surface Chemistry and Catalysis, Germany Currently, one of the most important research areas in energy science is the electrochemical energy conversion. The conversion can be accomplished in fuel-cells, in which a mixture of hydrogen- and oxygen-gas is electrochemically converted to produce energy. The platinum catalyst in fuel-cells reacts very sensitive to carbon monoxide, which is present in the feed- gas, due to the production process of hydrogen, and which poisons the platinum catalyst irreversible. To maintain the long-term activity of the platinum catalyst and hence the fuel cell, a refinement of the feed-gas is crucial. One way to achieve a carbon monoxide free hydrogen gas is to convert carbon monoxide via methanation-reaction to carbon dioxide, which is harmless to the platinum catalyst. A catalytic system based on ruthenium clusters supported on zeolites appears promising to achieve this goal. Ruthenium nano-particles smaller than 1 nm showed a very high activity and selectivity for the methanation-reaction of carbon monoxide. [1-3] To further examine the catalytic properties of ruthenium clusters a new experimental setup was designed based on the magnetron sputter technique to produce clusters of various sizes. A quadrupole mass filter in combination with an ion trap allows the probing of size selected clusters and their catalytic behavior. In particular, binary ruthenium-siliconoxide-clusters will be prepared this way to study mechanistic details of the zeolite-supported ruthenium catalyzed CO methanation reaction. Figure 1: Product mass spectrum (intensity in arbitrary units) obtained after the gas-phase + reaction of Ru4 with CO and D2 for 0.1 s. The corresponding calculated DFT structure of + H5Ru4(CO)12 is shown as an inset (Ru, C, O, and H atoms are indicated by green, gray, red and white spheres, respectively). (DFT Calculations by V. Bonačić-Koutecký) [2] [1] S. Eckle, Y. Denkwitz, R. J. Behm, J. Catal. 2010, 269, 255–268. [2] S. M. Lang, S. U. Förtig, T. M. Bernhardt, M. Krstić, V. Bonačić-Koutecký, J. Phys. Chem. A 2014, 118, 8356–8359. [3] S. M. Lang, T. M. Bernhardt, M. Krstic̈ , V. Bonačic̈ -Koutecký, Angew. Chemie - Int. Ed. 2014, 53, 5467–5471. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Reactivity and catalysis B30 Forming atom-vacancy interface on the MoS2 catalyst for effective hydrodeoxygenation reactions Q. Li1, X. Bai1, C. Ling1, Q. Zhou1, S. Yuan1, Q. Chen1, J. Wang1 1 School of physics, Southeast University, China [email protected] Atomically dispersed supported catalysts show superior catalytic activity and selectivity in diverse reactions, while the challenging part is identifying the active sites and revealing the reaction mechanisms, which play essential roles in rational design of efficient catalysts towards to massive energy consumption reduction [1-2]. In this study, we propose an atom vacancy interface (AVI) model for the first time, based on a case study of atomically dispersed Co atoms distributed on MoS2 surfaces as promising catalysts for hydrodeoxygenation (HDO) reactions [3-5]. Our results show that the reactive single Co atom promotes the H2 activation and leads to largely increased sulphur vacancies adjacent to the metals, thus metal vacancy interfaces are formed. Detailed reaction mechanism studies demonstrate that the AVI model corresponds to a metal - Lewis acid type of catalyst, which is quite different from Lewis acid - Brønsted acid mechanism as found in unprompted MoS2 and traditionally prepared CoMoS2 catalysts. The novel structure results in a considerable reduction of energy barriers of three elementary steps including S-C scission, hydrogenation processes and catalytic center regeneration, and eventually boots the HDO reaction at low temperatures. Figure 1: Schematic of a metal vacancy interface model as a promising HDO catalyst. [1] Qiao B., Wang A., Yang X., et al., Single-atom catalysis of CO oxidation using Pt1/FeOx, Nat. Chem. 2011, 3, 634-641. [2] Liu J., Catalysis by Supported Single Metal Atoms, ACS Catalysis 2016, 7, 34-59 [3] Liu G., Robertson A. W., Li M. M., et al., MoS2 monolayer catalyst doped with isolated Co atoms for the hydrodeoxygenation reaction, Nat. Chem., 2017, 9, 810-816. [4] Li Q., Zhao Y., Ling C., et al., Towards a Comprehensive Understanding of the Reaction Mechanisms Between Defective MoS2 and Thiol Molecules, Angew. Chem. Int. Ed. 2017, 56, 10501-10505. [5] Li H., Wang L., Dai Y., et al., Synergetic interaction between neighbouring platinum monomers in CO2 hydrogenation, Nat. Nanotech., 2018, doi:10.1038/s41565-018-0089-z. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Reactivity and catalysis B31 Cluster beam deposition of preformed metal clusters for liquid and gas phase catalysis Rongsheng Cai1, Peter R. Ellis2, Jinlong Yin3, Christopher M. Brown2, Kevin Cooke3, Peter T. Bishop2, Richard E. Palmer1 1 College of Engineering, Swansea University, Bay Campus, Fabian Way, Swansea SA1 8EN, UK 2Johnson Matthey, Blount's Court, Sonning Common, Reading RG4 9NH, UK 3Teer Coatings Ltd., Berry Hill Industrial Estate, Droitwich, Worcestershire WR9 9AS, UK [email protected] The deposition of preformed cluster beams onto suitable supports represents a new paradigm for the precise preparation of heterogeneous catalysts. Compared with traditional chemical methods, it exhibits a range of unique advantages including good size (and composition) control, no toxic reagents needed, absence of chemical ligands etc. However, for a long time the feasibility of cluster-beam deposited catalysts for reactions under realistic conditions has been limited by the low production rate. Based on our successful scale-up of the cluster flux [1], we present here two experimental validations of cluster catalysts, for liquid phase and vapour phase reactions, respectively. i) Au/Cu nanoalloy clusters of variable compositions on MgO powder supports, created by a dual-magnetron sputtering gas condensation cluster source, are found to be highly active for the catalytic reduction of 4-nitrophenol in solution [2]. The interplay between the Au and Cu atoms at the cluster surface appears to enhance the catalytic activity via the binding energies of product and reactant. In addition, the physically deposited clusters with Au/Cu ratio close to one show a 25-fold higher activity than a Au/Cu reference sample made by chemical impregnation. ii) Size-controlled Pd clusters deposited on diced graphite tapes from the Matrix Assembly Cluster Source (MACS) [3] are found to be much more active than a Pd reference sample made by wet impregnation in the vapour phase 1- pentyne selective hydrogenation reaction. Aberration-corrected scanning transmission electron microscopy of the cluster size evolution before and after reaction reveals that the superior activity derives from the smaller cluster size and better stability against sintering compared with the Pd reference sample. Thus the addition of Au atoms to the Pd clusters, which increases cluster diffusion and sintering, decreases the catalytic activity. References: [1] Peter R. Ellis et al, Faraday Discuss., 2016, 188, 39. [2] Rongsheng Cai et al, Small, 2018, 1703734 [3] Palmer R.E. et al, Rev. Sci. Instrum. 2016, 87, 046103. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Reactivity and catalysis B32 – Size-Dependent C–I Bond Activation of CH3IbyAun (n = 1–4) in the Gas Phase Satoru Muramatsu1, Kiichirou Koyasu1,2, Tatsuya Tsukuda1,2 1Department of Chemistry, The University of Tokyo, Japan 2Elements Strategy Initiative for Catalysts and Batteries (ESICB), Kyoto University, Japan Recent experimental and theoretical studies have demonstrated that Au nanoparticles and clusters catalyze various C–C coupling reactions which require activation of C(sp/sp2)–X (X: halogen) bond via oxidative addition [1]. In contrast, catalytic activation of C(sp3)–X bond in haloalkanes is considered to be more challenging due to electron-rich nature of sp3 carbon [2]. In order to understand whether and how Au clusters activate C(sp3)–X bond, we studied – the simple gas-phase reaction of CH3I with gold atom and small gold cluster anions, Aun (n = 1–4), by means of mass spectrometry (MS), photoelectron spectroscopy (PES), and DFT calculations. – Laser-ablated Aun (n = 1–4) were allowed to react with CH3I molecules in a reaction – cell. Kinetic analyses assuming pseudo-first order reaction with respect to the amount of Aun – revealed that Au2 shows the highest reactivity toward CH3I in this size region. It would be attributed to the lowest electron affinity of Au2 among Au clusters. With regard to products, Au– mainly afforded the oxidative addition product [I– Au– – – – CH3] as revealed by PES, while Au2 yielded Au2I (+ CH3). On the basis of calculations on the potential energy surfaces, we concluded that preferential site to attack on CH3I is different – – – between Au and Au2 , as shown in Figure 1. Au attacks from the C side of CH3IinanSN2 – – manner, followed by migration of leaving I (eq. 1) [3]. In contrast, Au2 attacks from the I side to directly abstract the I atom (eq. 2). Both reactions were barrierless and highly exothermic, and thus easily proceed. ‒ ‒ ‒ Au +CH3–I → [AuCH3…I ] → [I‒Au‒CH3] (1) ‒ ‒ Au2 + I–CH3 →Au2I +CH3 (2) The drastic size dependence in the C–I bond activation by Au clusters demonstrated in this study raises a possibility that Au cluster catalysts could control the products, or enhance the selectivity, by atomically tuning the cluster size. – – Figure 1. Preferential reaction site to attack on CH3IbyAu and Au2 . [1] Li, G. et al. Nanotechnol. Rev. 2012, 2, 529. [2] Frisch, A. C.; Beller, M. Angew. Chem. Int. Ed. 2005. 44, 674. [3] Muramatsu, S. et al. J. Phys. Chem. A 2016, 120,957. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Reactivity and catalysis B33 Prominent hydrogenation catalysis of PVP-stabilized gold clusters provided by doping a single heterometal atom S. Hasegawa1, S. Takano1, S. Yamazoe2,3,4, T. Tsukuda1,2 1 Department of Chemistry, The University of Tokyo, Japan 2 ESICB, Kyoto University, Japan 3 CREST, JST, Japan 4 Department of Chemistry, Tokyo Metropolitan University, Japan [email protected] Gold clusters stabilized by poly(N-vinyl-2-pyrrolidone) (Au:PVP) have provided an ideal platform for studying the correlation between cluster size and catalysis [1]: Au clusters smaller than 2 nm efficiently catalyze aerobic oxidation reactions [2]. We demonstrated that cluster size distribution of Au:PVP could be evaluated by matrix assisted laser desorption/ionization (MALDI) mass spectrometry [3]. In this study, we successfully doped a single Pd or Rh atom into Au:PVP as confirmed by MALDI mass spectrometry and found the emergence of hydrogenation catalysis and much higher activity of Rh-doped Au:PVP [4,5]. Pd-doped Au:PVP (AuPd:PVP) and Rh-doped Au:PVP (AuRh:PVP) were prepared by co- reduction of the mixture of HAuCl4 and PdCl2 or RhCl3, respectively, by NaBH4 in the presence of PVP [4,5]. We confirmed that no significant change in an average diameter (~1.2 nm) was induced by doping based on TEM, PXRD and optical spectroscopy. Only – – AunPd1 or AunRh1 appeared in the mass spectra of – AuPd:PVP or AuRh:PVP, respectively, whereas Aun were observed in the mass spectra of Au:PVP (Fig. 1). This result indicated that single-atom-doped clusters were dominant species in doped Au:PVP. Hydrogenation catalysis of pure and doped Au:PVP Fig. 1 MALDI mass spectra of (a) Au:PVP, was evaluated for olefins (Table 1). Only doped (b) AuPd:PVP and (c) AuRh:PVP. Au:PVP showed significant catalytic activity under Table 1 Catalytic hydrogenation reactions. mild reaction conditions; the emergence of hydrogenation catalysis was achieved by single-atom doping. Furthermore, AuRh:PVP was much more active than AuPd:PVP. Pd K- and Rh K-edge EXAFS H2 Conversion Reaction Dopant analysis suggested that the high catalytic activity of (MPa) (%) AuRh:PVP is derived from the low coordination state - <1 of a Rh dopant atom on an Au cluster compared to that (a) Pd 0.1 10 of Pd. Rh 90 - 1 (b) Pd 0.25 33 [1] H. Tsunoyama et al., J. Am. Chem. Soc., 2005, 127, 9374. Rh 95 [2] S. Yamazoe et al., Acc. Chem. Res., 2014, 47, 816. - <1 [3] H. Tsunoyama et al., J. Am. Chem. Soc., 2009, 131, 18216. (c) Pd 0.5 2 [4] S. Hayashi et al., Top. Catal., 2018, 61, 136. Rh 83 [5] S. Hasegawa et al., Chem. Commun., in press. Reaction conditions: substrate 50 μmol; catalyst 2 at%; PVP 111 mg; ethanol 5 mL; 303 K; 1 h. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Reactivity and catalysis B34 Surface and gas-phase experiments with Calcium-manganese-oxide clusters S. Mauthe, S. M. Lang, T. M. Bernhardt University of Ulm, Institute of Surface Chemistry and Catalysis, Germany [email protected] Manganese oxides are of great current interest regarding the biomimetic activation and oxidation of water. However, few is known so far concerning the activity of Mn-nanoclusters in this reaction. Therefore, in this contribution the possibility to prepare manganese and manganese oxide clusters on supported graphene is investigated with the further aim to study their activity as water splitting catalysts. As a first step, scanning tunneling microscopy was employed to investigate the adsorption of manganese and manganese oxide on the moiré-type structure of graphene on an Ir(111) single crystal surface. Most interestingly, the results demonstrate that manganese does not only form clusters on top of the graphene layer but also appears to intercalate in between the graphene layer and the iridium substrate even at room temperature (see figure 1). To further probe fundamental concepts of the water splitting reaction and to aid the design of artificial water-splitting molecular catalysts we prepared as a second step free manganese-oxide clusters as well-defined model systems and studied their reactivity in an ion trap experiment. The catalytically activated water-splitting takes place at an inorganic mono-calcium tetra- manganese penta-oxygen (CaMn4O5) cluster. For this reason we investigated the pentamer species with addition of a calcium atom in the gas-phase. In particular, clusters with an increased formal oxidation state of the manganese atoms are expected to show improved properties as an oxidizing agent for water. Therefore, we focused our investigations on the + reactivity of oxygen-rich species CaMnxOy (x Figure 1: STM image of an Ir(111)/ graphene/ Mn-system with a Mn deposition time of 50 sec.; (125 nm x 125 nm), tunneling parameters: I = 0.20 nA, U = -1.80 V. (A): Small clusters on top of the surface; (B): Intercalated Mn-nanocluster islands; (C): Moiré-superstructure which is formed by the mismatch of the Ir(111) and the graphene lattices. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Reactivity and catalysis B35 Active site structures of cationic cerium oxide clusters studied by ion mobility mass spectrometry and density functional theory calculations T. Nagata, J. W. J. Wu, M. Nakano, K. Ohshimo, F. Misaizu Department of Chemistry, Graduate School of Science, Tohoku University, Japan Cerium oxide (CeO2, ceria) is widely used as redox catalysts. Gas-phase cerium oxide clusters have been investigated as a model system of ceria-based catalysts [1,2]. In this study, we studied + geometrical structures and reactions of cerium oxide cluster cations, CenO2n (n = 2–5), by ion mobility mass spectrometry (IMMS) for revealing their active site structures. Cerium oxide cluster cations were generated by laser ablation of ceria in He carrier gas. The ions were measured by IMMS to obtain collision cross sections (CCSs) using an ion-drift cell filled with He buffer gas and a time-of-flight mass spectrometer. Candidate structures of the ions were optimized by density functional theory (DFT) calculations, and their theoretical CCSs were simulated. Structures of cerium oxide cluster cations were assigned by comparing the experimental and theoretical CCSs. + + + + Results for oxygen deficient ions, Ce2O3 ,Ce3O4 ,Ce3O5 ,andCe5O9 , were consistent with + reported structures determined by infrared spectroscopy [3]. However, for CenO2n ions, more compact structures were suggested than reported DFT-calculated structures [1]. These compact + structures of CenO2n hold less terminal oxygen atoms, which were regarded as active sites + + (Figure 1a). We also studied CenO2n(NO) , formed by reaction of CenO2n with NO, by IMMS. + 2 As a result, the CCSs of CenO2n(NO) were determined to be 2–6 Å larger than those of + + CenO2n . A suggested structure of Ce4O8(NO) contains a NO2 moiety from the NO and a + terminal O atom of Ce4O8 (Figure 1b). + Figure 1: (a) Assigned structures of CenO2n from CCSs measurement. (b) Structures before and + after adsorption of NO on Ce4O8 . [1] X.-N. Wu et al., Phys. Chem. Chem. Phys. 12 (2010) 3984. [2] T. Nagata et al., J. Phys. Chem. A 119 (2015) 10255. [3] A. M. Burow et al., Phys. Chem. Chem. Phys. 13 (2011) 19393. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Reactivity and catalysis B36 Catalytic Activities of Nanoalloy PtmRhn (m + n = 38) for CO Oxidation: A Density Functional Theory Investigation Wei Pei, Si Zhou*, Yizhen Bai, Jijun Zhao Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, Dalian 116024, China E-mail: [email protected] (Si Zhou) Abstract Using the CO oxidation as a chemical probe, we perform a comprehensive the first principle study of catalytic activities of nanoalloy PtmRhn (m + n = 38). Adsorption energies of a single CO or O2 molecule as well as coadsorption energies of both CO and O2 molecules on various distinctive surface sites of each cluster. Our calculations also demonstrate that PtmRhn should have a lower activation barrier than traditional catalyst of Cu(111) surface. Therefore, we also study H2 and CO2 adsorption on the nanoalloy surface sites of PtmRhn. The adsorption energy of H2 bonding with Pt atoms more low than Rh atoms, and a H2 molecule will split two H atoms on the Pt sites. However, CO2 molecule have more strong interaction with Rh sites than Pt of PtmRhn, and its activity could be active due to the molecular structure of CO2 has been broken. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Reactivity and catalysis B37 MXene nanoribbon as electrocatalysts for hydrogen evolution reaction with fast kinetics Xiaowei Yang1, Nan Gao1, Si Zhou1 Jijun Zhao1 1 Key Laboratory of Materials Modification by Laser, Ion and Electron Beams(Dalian University of Technology), Ministry of Education, Dalian 116024, China Abstract MXenes, a new class of two-dimensional materials, arouse great interests due to their diverse chemistries, superior electrical conductivity and stability. Recently, the nanostructures of MXenes such as nanoribbons and nanodots have been synthesized in experiment, which show peculiar properties and expand the application spectrum of MXenes. Here we exploited MXene nanoribbons as potential electrocatalysts for hydrogen evolution reaction (HER) by considering 12 kinds of MXene systems. Our first-principles calculations showed that the edges of MXene nanoribbons can adsorb hydrogen species and serve as the reaction sites for hydrogen evolution. The binding strength of the ribbon edge is correlated to the d band center of metal atoms in MXenes. In particular, the nanoribbons of Ti3C2 and (Ti, Nb)C solid solution exhibit high activity for HER with the adsorption free energy approaching zero and Tafel barrier below 0.36 and 0.17 eV, respectively. The low barrier is owing to the prominent charge transfer from the edge metal atoms to the H* reactants in the transition state. These theoretical results illuminate the principle for designing MXene nanostructures for electrocatalysts with fast kinetics, and shine light in utilizing MXenes with more than one metal elements for a broad range of electrochemical reactions. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Reactivity and catalysis B38 Molybdenum Sulfide Nanomaterials for Electrocatalytic Hydrogen Evolution Yixin Ouyang1, Chongyi Ling1, Li Shi1, Jinlan Wang1 1School of Physics, Southeast University, China Molybdenum sulfide is an intensely attractive noble-metal-free electrocatalyst for the hydrogen evolution reaction (HER) [1,2]. In order to enhance the HER activity, tremendous effort has been made to engineer molybdenum sulfide catalysts with either more active sites or higher conductivity [3]. In our work, we focus on activating the inert basal planes of MoS2 and designing molybdenum sulfide cluster catalysts. We assessed 16 kinds of structural defects including point defects and grain boundaries of the MoS2 monolayer as catalytic centers and atomic palladium doping was used to introduce defects. We also designed a composite catalyst, which is composed of molybdenum sulfide clusters and defective graphene, holding excellent intrinsic activity, high-density active sites and high conductivity simultaneously. Figure 1: Schematic of an ideal molybdenum sulfide based catalyst with both high activity and long-term durability. [1] B. Hinnemann, P. G. Moses, J. Bonde, K. P. Jorgensen, J. H. Nielsen, S. Horch, I. Chorkendorff and J. K. Nørskov, J. Am. Chem. Soc., 2005, 127, 5308. [2] H. Li, C. Tsai, A. L. Koh, L. L. Cai, A. W. Contryman, A. H. Fragapane, J. H. Zhao, H. S. Han, H. C. Manoharan, F. Abild-Pedersen, J. K. Nørskov and X. L. Zheng, Nat. Mater., 2016, 15, 48. [3] Y. Liang, Y. Li, H. Wang and H. Dai, J. Am. Chem. Soc., 2013, 135, 2013. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Reactivity and catalysis B39 High-performance gas phase synthesized palladium nanoparticles for H2O2 sensing and methanol electro-oxidation Jue Wang1 and Min Han1 1 National Laboratory of Solid State Microstructures and Department of Materials Science and Engineering, Nanjing University, Nanjing 210093,China In recent years, Pd nanoparticles (NPs) have attracted much research interests in H2O2 sensing and methanol electro-oxidation applications. Pd NPs used for electro-catalytic applications was commonly synthesized by chemical routes such as chemical reduction and electrodeposition. In each case, it is inevitable that the chemical solution would affect the catalytic activity. Recently, We used the gas phase cluster beam deposition process to fabricate Pd NP-deposited-glassy carbon electrode (GCE), which enabled highly selective amperometric detection of H2O2 at a sufficiently low applied potential (−0.12 V) [1]. In order to improve the response time and the linear response range, Pd NPs were deposited on chemical vapor deposition synthesized bilayer graphene films (BGFs) supported with GCEs in the gas phase. With the introduction of BGFs, the catalytic activity of Pd NP-modified electrodes toward H2O2 reduction was largely enhanced [2]. Because of outstanding catalytic activity of the Pd NPs, we fabricated Pd NPs supported on carbon supports and used them as the electro-catalysts for methanol oxidation reactions. The resulting Pd NPs/multi-walled carbon nanotubes/few-layer graphene sheets combination exhibits an ultrahigh electrocatalytic activity and unusual long-term durability for methanol oxidation [3]. These results indicate that the Pd NP catalysts produced by gas phase cluster beam deposition are promising applications in H2O2 sensing and methanol electro- oxidation. Figure 1: TEM images of Pd NPs deposited for (a) 10 min, (b) 20 min, and (c) 30 min. (d-e) TEM image of the MWCNTs/FLG and Pd NPs/MWCNTs/FLG. (f) Raman spectrum of the FLG and MWCNTs/FLG. [1] J. Wang, et al., Nanoscale Res. Lett. (2015) 10:311 [2] J. Wang, et al., Sensor. Actuat. B-Chem. 230 (2016) 690–696 [3] J. Wang, et al., Electrochim. Acta 251 (2017) 631–637 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Spectroscopy and dynamics B40 - Photoelectron Spectroscopy and Theoretical Study of AlCn (n = 3-13) Chaojiang Zhang1,2, Peng Wang1, Bin Yang1,2, Xi-Ling Xu1, Hong-guang Xu1, and Wei-Jun Zheng1 1State Key Laboratory of Molecular Reaction Dynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China 2University of Chinese Academy of Sciences, Beijing 100049, China Email: [email protected] - We investigated the AlCn (n = 3-13) clusters combination with photoelectron spectroscopy and - DFT calculations. The most probable ground-state isomers of AlCn (n = 3-13) were confirmed - by comparing the calculated VDEs with the experimental results which show that the AlCn (n= 3-13) clusters are linear structure with the Al atom locating at one end of the carbon chain. The - VDEs and spins of AlCn (n = 3-13) clusters display an obvious parity effect with an increasing number of carbon atoms. The VDEs of even-n clusters are higher than those of adjacent odd-n clusters. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Spectroscopy and dynamics B41 Valence Electronic Properties and Interfacial Solvation of Phenolic Aqueous Nanoaerosols Probed via Aerosol VUV Photoelectron Spectroscopy Chia C. Wang 1 Department of Chemistry, National Sun Yat-sen University, Kaohsiung, Taiwan 2 Aerosol Science Research Center, National Sun Yat-sen University, Kaohsiung, Taiwan [email protected] An in-depth understanding of the fundamental energetic and structural properties at or near the interface of nanoscaled aqueous aerosols is of fundamental and crucial importance in understanding the impacts of organic species, either of biogenic or anthropogenic origins in intervening the cloud formation microphysics and the intrinsic nature of clouds. To address these issues, we applied the recently-developed aerosol VUV photoelectron spectroscopy [1,2] to investigate the valence electronic structures and interfacial characteristics of several organic- containing aqueous nanoaerosols that are of atmospheric significance. Phenol and phenolic compounds represent a major resource of secondary organic aerosols (SOA) in the atmosphere. We applied the recently constructed aerosol VUV photoelectron spectroscopy to investigate for the first time the valence photoelectron spectroscopy of phenol and three dihydroxybenzene (DHB) isomers in the aqueous nanoaerosol form, using the synchrotron-based VUV radiation as the ionization source [3]. By evaluating two photoelectron features of the lowest vertical ionization energies (VIE) originated from the b1(π) and a2(π) orbitals for phenolic aqueous nanoaerosols, their pH-dependent valence electronic structures and interfacial solvation characteristics are unraveled. Both phenol and phenolate are highly surface-active. On the aqueous aerosol interface, they appear only partially solvated, with the hydrophilic –OH/-O- group better immersed in water and the hydrophobic aromatic ring remaining above the interface of aqueous aerosols. Deprotonations of phenolic species accompanying with increasing pH appear to enhance the hydration extent, likely due to the stronger solute-solvent interactions between the negatively charged –O- group and water solvent molecules. A significant fraction of neutral phenol is observed along with phenolate at pH of 12.0, indicating that the chemical composition and surface pH at the aqueous aerosol interface deviate from the bulk. It reveals that the hydration extents, pH values, deprotonation status, and numbers/relative arrangements of −OH groups are crucial factors affecting the ionization energies of phenolic aqueous nanoaerosols and thus their redox-based activities. The multi-faceted implications of the present study in the aerosol science, atmospheric/marine chemistry, and biological science will be addressed. References [1] C.-C. Su, Y. Yu, P.-C. Chang, Y.-W. Chen, I. Y. Chen, Y.-Y. Lee, C. C. Wang, J. Phys. Chem. Lett. 2015,6, 817. [2] P.-C. Chang, Y. Yu, W.-R. Chen, C.-C. Su, M.-S. Chen, Y.-L. Li, T.-P. Huang, Y.-Y. Lee, C. C. Wang, J. Phys. Chem. B, 2016, 120, 10181. [3] P.-C. Lin, Z.-H. Wu, M.-S. Chen, Y.-L. Li, W.-R. Chen, T.-P. Huang, Y.-Y. Lee and C.C. Wang*, J. Phys. Chem. B, 2017, 121, 1054. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Spectroscopy and dynamics B42 Study on the shielding effect of a microelectrode tip for scanning probe electron energy spectroscopy Wei Huang1,ZheanLi1, Zhongfeng Li1, Chunkai Xu1,2, Xiangjun Chen1,2 1 Department of Modern Physics, University of Science and Technology of China, Hefei, 230026, China. 2 Hefei National Laboratory for Physical Sciences at the Microscale, and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, 230026, China. We have successfully fabricated a novel tip for scanning probe electron energy spectroscopy (SPEES), which is based on a regular STM tip shielded by a microelectrode. The shielding effects of this microelectrode tip (ME tip) and a normal tip on detection efficiency are studied experimentally by a home-made SPEES instrument [1]. Simulations are also conducted by SIMION 8.0 to confirm the experimental results, which fit the experiments pretty well. The results are shown in Fig. 1. It is illustrated that the backscattering count rate detected by SPEES instrument using normal tip begins to decrease as the tip approaches to the sample surface within 21 m, while that using ME tip only starts to drop off within 1 m. This demonstrates that the ME tip can significantly reduce the tip-sample distance for spectroscopic measurement. Compared with our previous SPEES experiments [1-3], electron energy loss spectrum of Ag nanostructures on HOPG surface is measured at a much closer tip-sample distance of 1.4 m with the ME tip, meanwhile in situ topography is obtained. This indicates that this type of novel tip is available for SPEES experiment, which will improve the spectroscopic spatial resolution of SPEES technique in the future. Figure 1: The dependences of count rate on tip-sample distance for ME tip and normal tip, obtained by experiment and simulation. [1] M. Li, C. K. Xu, P. K. Zhang, Z. A. Li, and X. J. Chen, Rev. Sci. Instrum. 87, 086108 (2016). [2] C. K. Xu, X. J. Chen, X. Zhou, Z. Wei, W. J. Liu, J. W. Li, J. F. Williams, and K. Z. Xu, Rev. Sci. Instrum. 80, 103705 (2009). [3] C. K. Xu, W. J. Liu, P. K. Zhang, M. Li, H. J. Zhang, K. Z. Xu, Y. Luo, and X. J. Chen, NaturePhys. 10, 753- 757 (2014). 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Spectroscopy and dynamics B43 Molecular Photoreactiondynamics of small molecules on TiO2 E. Artmann1, F. Knall1, T. M. Bernhardt1 1 Institute of Surface Chemistry and Catalysis / University of Ulm, Germany Nanostructured titanium dioxide and titanium oxide nanoparticles are important and widely employed photooxidation catalysts. It is therefore of special interest to understand the photocatalytic processes occurring on these materials in order to be able to optimize their performance. Since many photooxidation reactions are of high complexity and not fully understood yet, we employ pump-probe-fs-laser-mass-spectrometry measurements to identify the dynamics of intermediates and products which form during the photooxidation of adsorbates on TiO2(110). As ketones and halides are often residues in organic contaminants the measurements are carried out with acetone, butanone and methyl iodide. Supportive temperature programmed desorption (TPD), Auger electron spectroscopy (AES) and low energy electron diffraction (LEED) measurements were performed. Furthermore, the influence of amount of surface defects on the molecular reaction dynamics and the effect of preadsorbed oxygen on the surface were examined. Because surface defects have a considerable influence on the electronic structure of TiO2(110) additionally, two-photon-photoelectron (2PP) spectroscopy measurements with p- and s- polarized light, respectively, and acetone as an adsorbate molecule are also carried out. These measurements showed a ‘wet-electron’ state above the Fermi level. The ‘wet-electron’ state could be assigned to a Ti-3d defect state and disappeared if preadsorbed oxygen was present on the surface. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Spectroscopy and dynamics B44 Infrared Spectroscopy of Boron Complexes J. Jin, G. Wang, M. Zhou Department of Chemistry, Fudan University, China The structures and bonding of boron compounds remain an outstanding question in cluster science. [1] Gas phase infrared photodissociation spectroscopy combined with state-of-the-art quantum chemical calculations has proved to be an effective method to investigate the geometric and electronic structures, as well as chemical bonding of ion complexes. Here, I will highlight our recent studies on the formation and infrared spectroscopic characterization of several boron complexes including boron-carbonyl and boron-dinitrogen complexes, as well as + + boron oxide clusters. [2-4] The B3 in B3L3 (L = CO/NN) are characterized as the smallest + Hückel π aromatic species. The B3(CO)4,5 complexes have linear chain geometries and are considered to be analogues of the hydrocarbon molecules. A boroxol ring, B3O3 and a boron- + argon dative bond are found in the series of planar [ArBxOy] species. These findings help to expand fundamental understanding of structures and bonding of boron compounds. [1] Sergeeva, A.P.; Popov, I.A.; Piazza, Z.A.; Li, W.L.; Rommanescu, C.; Wang, L.S.; Boldyrev, A.I. Acc. Chem. Res. 2014, 47 1349-1358. [2] Jin, J.Y.; Wang, G.J.; Zhou, M.F.; Andrada, D.M.; Hernmann, M.; Frenking, G. Angew. Chem. Int Edit. 2016, 55, 2078-2082. [3] Jin, J.Y.; Li, W.; Liu, Y.H.; Wang, G.J.; Zhou, M.F. Chem. Sci. 2017, 8, 6594-6600. [4] Jin, J.Y; Wang, G.J.; Zhou, M.F. J. Phys. Chem. A. 2018, 10, 2688-2694. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Spectroscopy and dynamics B45 X-ray Spectroscopy and Electron Density of States Analysis of As2S3 phases: A First Principle Study L. Mohammed1,2,3, Q. Zhang1, M. A. Saeed4 A. Musa3,4, A. Sharma1, K. Tadele1 1School of Material Science and Engineering Yancheng Institute of Technology, China 2Physics Department Ahmadu Bello University Zaria, Nigeria 3Physics Department Bayero University Kano, Nigeria 4Physics Department Universiti Teknologi Malaysia [email protected] X-ray absorption near-edge structure (XANES) is one of the most widespread spectroscopies for studying the chemical properties of materials. It is a sensitive probe of the atomic environment, because it can be used to effectively measure the transition probability between core electrons and unoccupied states. In this paper, single level excitonic effects on the core state of the polymorph of As2S3 and tetragonal In2S3 were studied using X-ray absorption spectroscopy. Our results for the first time show striking similarities in Arsenic L3 (s, d)-edges peaks for the two phases of As2S3 orpiment and anorpiment crystals. Optical absorption increases mostly due to core-hole for S K (p) and As L3-edges in orpiment as compared to the other structures. The core-level calculations for these orbitals show good agreement with the experimental ones thus validating the approach used in this study. In orpiment and anorpiment, an indirect energy band gap which has been improved by the mBJ potential to about 1.03 eV and 0.65 eV respectively was observed. We have calculated the imaginary dielectric function and the absorption coefficient with the mBJ potential and core-hole, the optical excitations, is observe to be enhance by core level spectroscopy for all the crystals. Furthermore, the bond length and angles of monoclinic and triclinic As2S3 as well as the beta-phase In2S3 compared well with the experimental results. Structural optimization and total energies of all structures are computed using the all electrons full potential linearized augmented plane wave plus local orbitals (FP-LAPW + lo) within the framework of DFT. References [1] Z. Zhao, J. Yi and D. Zhou, Computational Materials Science, 73, 139-145, (2013). [2] Y. Sharma and S. Pankaj, Materials Chemistry and Physics, 135, 385-394, (2012). [3] M. Lawal., M. A. Saeed & A. Musa Solar Energy, 137, 621-627, (2016). [4] C. Ambrosch-Draxl and J. O. Sofo, Computer Physics Communications, 175, 1-14, (2006). [5] M. I. Aroyo, J. M. Perez-Mato, C. Capillas, E. Kroumova, S. Ivantchev, G. Madariaga, A. Kirov and H. Wondratschek, Crytalline Materials, 221, 15-27, (2006). 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Spectroscopy and dynamics B46 Conquest of the high DOS problem – spectroscopy on the individual quantum state M. Beck1, P. Bornhauser1,B.Visser1, G. Knopp1, J. A. van Bokhoven2,3,P.P.Radi1 1 Photon Science Division, Paul Scherrer Institute, Switzerland 2 Energy and Environment Research Division, Paul Scherrer Institute, Switzerland 3 Department of Chemistry and Applied Biosciences, ETH Zurich, Switzerland [email protected] Quantum-sized transition metal systems are the key element to many of the most relevant processes in chemistry, biology and physics. Still, the high density of states (DOS), which is emerging on their excitation, so far hindered both experimental and computational insight into the interplay of the underlying quantum states. While high resolution spectroscopy commonly fails by just revealing an impenetrable thicket of overlapping features, quantum chemical ab initio methods do not scale sufficient to handle an active space of the required size. In this work, we used two-color resonant four-wave mixing spectroscopy to study the neutral copper dimer in gas phase. We already demonstrated the applicability of the method by adding to the picture of the low-lying electronic states,1 and also gained some knowledge on unperturbed high-lying features.2 However, here, we finally present the deperturbation of the full studied range in the deep UV. By utilizing the double resonance selection rules to pin the rotational quantum number in the ground state, we could unambiguously assign more than thousand individual rovibronic transitions. These not only revealed the known bright states, but also about ten vibronic levels of perturbing dark states, just visible at their intersections with bright states. Figure 1 exemplary shows the intersections of two dark states with a bright state (left) and a simulation of a one-color spectrum based on the obtained constants (right). Figure 1: a, shows a series of two-color spectra of the 63Cu65Cu isotopologue, ordered by the assigned rotational quantum numbers J" of (2-0) J-X transitions (red). Green resp. blue highlighted regions contain lines assigned to a weakly resp. strongly perturbing dark state. b, 63 63 65 illustrates how the two most abundant isotopologues Cu2 (dark colors) and Cu Cu (light colors) form a one-color spectrum of the (0-0) J-X transition, perturbed by 3 dark states. [1] B. Visser et al. J. Chem. Phys. 147, 214308 (2017). [2] M. Beck et al. J. Phys. Chem. A, 121, 44, 8448–8452 (2017). 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Spectroscopy and dynamics B47 Photoelectron Spectroscopy of Sodium Thiocyanate Shi-yan Gong,† Hong-Guang Xu,‡ Wei-Jun Zheng,‡,§,* ‡State Key Laboratory of Molecular Reaction Dynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China E-mail: [email protected] (W.J.Z.); Sodium thiocyanate is a nucleophilic reagent that is often used in organic reactions. We studied the interaction of sodium thiocyanate and water molecules by collecting photoelectron spectroscopy. We investigated the NaSCN(H2O)n− and (NaSCN)2(H2O)n− (n = 0−6) clusters using photoelectron spectroscopy, and the molecular structure was optimized by density functional theory (DFT). The theoretical VDE was calculated by a higher base group, and the results are compared with the photoelectron spectroscopy. The contact ion pair (CIP) changed to solvent-separated ion pair (SSIP) in NaSCN(H2O)n clusters when n = 2, this is the anionic molecule that we know can be separated by the least water molecules. The results show that this is also the case with bimolecular sodium thiocyanate, SSIP formed due to the effect of two water molecules. This work helps us understand the effect of sodium thiocyanate on water molecules. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Spectroscopy and dynamics B48 Remarkable Blue-Shift of O-H Vibration Frequency Observed in the Gas Phase X.L. Kong1, 2 1 The State Key Laboratory of Elemento-organic Chemistry, Nankai University, Tianjin, 300071, China. 2 Collaborative Innovation Center of Chemical Science and Engineering, Nankai University, Tianjin 300071, China Compared to red-shifted vibrations, blue-shifted ones have seldom been reported experimentally [1]. For the O-H bond, blue shifts of ν(O–H) were only predicted theoretically for some complexes due to the existence of so-called blue-shifted hydrogen bonds. On the other hand, the blue shift of ν(O–H) due to the existing of metal atoms has been neglected by both experimental and theoretical chemists for a long time. One possible reason is that these kinds of species are typically too difficult to be generated in the gas phase. In this study, novel ions of + ScnO2n+2Hn+5 (n=3-7) have been generated by laser ablation of a mixture of Sc2O3 and graphene at 355 nm and have been identified by the accurate mass measurement with the FT ICR MS. Remarkably, the largest blue-shift of OH vibration was observed in their IRPD spectra. indicating their unique structures and properties. [1] P. Hobza, Z. Havlas , Blue-Shifting Hydrogen Bonds, Chem. Rev. 2000, 100, 4253-4264 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Structure and thermodynamics B49 Shape fluctuation of metallic nanoclusters: observations from long-timescale simulations Rao Huang1, Yuhua Wen1, Arthur F. Voter2, Danny Perez2 1 Department of Physics, Xiamen University, China 2 Theoretical Division T-1, Los Alamos National Laboratory, USA Metallic nanoclusters are functional materials with many applications owing to their unique physical and chemical properties, which are sensitively controlled by their shapes and structures. An in-depth understanding of their morphology stability is therefore of crucial importance. It has been well documented by transmission electron microscopy (TEM) studies that metallic nanoclusters can interconvert between different isomers. However, the relevant mechanisms remain elusive because the timescales of such shape fluctuations are too short to be resolved experimentally and yet too long for conventional atomistic simulations. By employing a recently introduced Accelerated Molecular Dynamics method, Parallel Trajectory Splicing, we present simulations that reached timescales of milliseconds and thus provide a clear description of the dynamic process of the experimentally observed shape fluctuation in metallic nanoclusters. We observe transformations back and forth between face-centered-cubic (fcc) and structures with five-fold symmetry (decahedron or icosahedron). These transitions occur following either by a partial-dislocation-mediated twinning mechanism or by a surface- reconstruction driven process. The identified pathway is in remarkable agreement with the existing microscopy results and serves as further evidence that shape fluctuation can occur directly through thermal activation, without involving melting or other external factors. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Structure and thermodynamics B50 Towards Exact Molecular Dynamics Simulations with Machine-Learned Force Fields and Molecular Properties H.E. Sauceda1, S. Chmiela2, K.T. Schütt2, K.-R. Müller2, A. Tkatchenko3 1 Fritz-Haber-Institut der Max-Planck-Gesellschaft, Germany 2 Machine Learning Group, Technische Universität Berlin, Germany 3 Physics and Materials Science Research Unit, University of Luxembourg, Luxembourg [email protected] Molecular dynamics (MD) simulations employing classical force fields constitute the cornerstone of contemporary atomistic modeling in chemistry, biology, and materials science. However, the predictive power of these simulations is only as good as the underlying interatomic potential. Classical force fields are based on mechanistic models of atomic interactions, which often fail to faithfully capture key quantum effects in molecules and materials. Here we enable the direct construction of flexible molecular force fields from high- level ab initio calculations by incorporating spatial and temporal physical symmetries into a gradient-domain machine learning (sGDML)[1, 2] model in an automatic data-driven way, thus greatly reducing the intrinsic complexity of the force field learning problem. The developed sGDML approach faithfully reproduces global force fields at quantum-chemical CCSD(T) and DFT{PBE0+MBD} level of accuracy and for the first time allows converged molecular dynamics simulations with fully quantized electrons and nuclei for flexible molecules and clusters with up to a few dozen atoms. Additionally, the combination of such results with molecular dipolar moments learned via continuous-filter convolutional neural networks (SchNet)[3], allows the prediction of accurate infrared spectrum (IR). In order to evince the applicability of our model, we present path-integral MD simulations at different temperatures for a set of boron rotors and demonstrate new insights into the dynamical behavior of these clusters. Furthermore, we investigate the nuclear quantum effects and its spectroscopic implications at low temperatures revealing insightful results on its vibrational behavior. In particular, an excellent agreement between theory and experiment is obtained by comparing the + IR spectrum for B13 . Our approach of learning highly accurate force fields and molecular properties provides the key missing ingredient for achieving spectroscopic accuracy in molecular simulations. Figure 1: Pictorial representation of the method. The data, x: coordinates, F: forces and P: dipolar moments, is collected from classical ab initio MD simulations, and then used to train our machine learning models for F(x) and P(x). The sampling of the energy surface and predicted IR are shown in the rightmost panel. [1] S. Chmiela, A. Tkatchenko, H. E. Sauceda, I. Poltavsky, K. T. Schütt, and K.-R. Müller “Machine Learning of Accurate Energy-conserving Molecular Force Fields” Science Advances 3, e1603015 (2017) [2] S. Chmiela, H. E. Sauceda, K.-R. Müller, and A. Tkatchenko “Towards Exact Molecular Dynamics Simulations with Machine-Learned Force Fields” submitted (2018). [3] K. T. Schütt, H. E. Sauceda, P.-J. Kindermans, A. Tkatchenko, and K.-R. Müller “SchNet – A deep learning architecture for molecules and materials” J. Chem. Phys. 148, 241722 (2018). 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Structure and thermodynamics B51 Quantification of chirality in clusters and nanostructures A. Patricio García, Ignacio L. Garzón Instituto de Física, Universidad Nacional Autónoma de México, 01000 CDMX, México Chirality has been found as a relevant property of nanomaterials, including ligand-protected metal clusters and nanoparticles. This property is not only crucial in nanotechnology developments related with asymmetric catalysis and chiroptical phenomena, but also generates fundamental questions on the existence of chirality at the nanoscale. Moreover, the geometric quantification of chirality and its correlation with physicochemical properties of chiral molecules, clusters, and nanoparticles is an emerging and interesting field of research in Physical Chemistry. In this work, we present a comparative analysis of the degree or amount of chirality existing in chiral ligand-protected gold clusters (LPGC), through a geometric quantification, using the Hausdorff chirality measure (HCM) [1]. The calculated HCM values provide a quantitative framework to compare, classify, and gain insight into the origin of chirality. Interestingly, these values are consistent with the current knowledge on the different sources of chirality: achiral cores and chiral arrangement of ligands in, for example, Au102(SR)44 and Au38(SR)24, or intrinsically chiral cores, like in Au52(SR)32 and Au20 protected with phosphine ligands. The calculated HCM values are used to extract trends on how chirality is spatially distributed in LPGC and correlate them with optical activity measurements. The main trend indicates that the Au-S interface has the dominant role in the chirality of LPGC [1]. More recently, the HCM methodology was also employed to geometrically quantify the chirality existing in all-carbon double helices along with their helical fragments [2], and in the tetrahedral closed-shell chiral cluster of 29 silver atoms &12 lipoate ligands [3]. Figure 1. Calculated HCM values and structures of Aun(SC6)m clusters. [1] J. J. Pelayo, R. L.Whetten, I. L. Garzón “Geometric Quantification of Chirality in Ligand-Protected Metal Clusters” J. Phys. Chem. C 119, 28666 (2015). [2] S. Castro-Fernández, R. Yang, A. P. García, I. L. Garzón, H. Xiu, A. G. Petrovic, J. L. Alonso-Gómez “Diverse Chiral Scaffolds from Diethynylspiranes: All-Carbon Double Helices and Flexible Shape- Persistent Macrocycles” Chem. Eur. J. 23. 11747 (2017). [3] P. Lopez, H.H. Lara, S.M. Mullins, D.M. Black, H. M. Ramsower, M.M. Alvarez, T.L. Williams,X. Lopez- Lozano, H.-C. Weissker, A. Patricio García, I.L. Garzón, B. Demeler, J.L. Lopez-Ribot,M. Jose-Yacaman, R.L. Whetten “Tetrahedral (T) Closed-Shell Cluster of 29 Silver Atoms & 12 Lipoate Ligands, [Ag29(R-a- (3-) LA)12] : Antibacterial and Antifungal Activity” ACS Appl. Nano Mater. 1, 1595 (2018). 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Structure and thermodynamics B52 Similarities and Differences in Structural Growth in Group 5 Metal Oxide Cluster Ions Studied by Ion Mobility Mass Spectrometry J. W. J. Wu1, R. Moriyama1, M. Nakano1,2, K. Ohshimo1, F. Misaizu1 1 Department of Chemistry, Graduate School of Science, Tohoku University, Japan 2 Institute for Excellence in Higher Education, Tohoku University, Japan [email protected] [Introduction] Group 5 metal oxides (vanadium, niobium, or tantalum oxides) are important catalysts used in numerous industrial processes, and they are also used as support for catalysts because of their reducible nature. In the bulk phase, they exist as pentoxides (M2O5, M = V, Nb, or Ta), where the metal has a formal oxidation state of +5. Gas phase cluster studies have provided means to model catalytic sites and reaction mechanisms of the bulk phase metal oxides, such as experimental studies incorporated with mass spectrometers. In this study, a combination of ion mobility mass spectrometry and theoretical calculation was utilized to study +/ geometrical structures of group 5 metal oxide cluster ions MmOn (M = V, Nb, and Ta), and the difference in the structure growth as the constituent metal changes. [Experimental] Vanadium oxide, niobium oxide, and tantalum oxide cluster ions were generated by laser vaporization and supersonic expansion of 5 - 10% O2/He mixture gas, and they were injected into an ion drift cell for ion mobility analysis followed by mass analysis with a time-of-flight mass spectrometer. The cluster ions were separated based on their collision cross sections (CCSs) to He buffer gas inside the ion drift cell, which is characterized as the +/ difference in flight time in the cell. Next, proposed geometrical structures of MmOn were optimized by density functional theory with Gaussian09 program, and the theoretical CCSs of the corresponding structures were calculated with MOBCAL program [1]. [Results and Discussion] By observing the mass spectrum, the stable species found upon + + + collision induced dissociation for VmOn were (VO2)(V2O5)(m-1)/2 and (V2O4)(V2O5)(m-2)/2 for cluster ions with odd and even number of m, respectively. These species are formed by stable building blocks such as VO2,VO3, and V2O5. Similarly, for niobium oxide, the stable species + + + + are (NbO2)(Nb2O5)(m-1)/2 and (Nb2O5)m/2 . The most stable structures for V4O9 and Nb4O10 were found to have tetrahedral framework as shown in Figure 1, which was reported in past theoretical and experimental studies [2-3]. Furthermore, it should be noted that for the + most abundant M4On compositions, the number of oxygen atoms n increases with increasing mass of the constituent metal M, from n = 9 in vanadium oxide to n = 10 in niobium oxide, and then to n = 11 in tantalum oxides as suggested in Figure 1. From the + geometrical structures, it can be concluded that Figure 1: Geometrical structures of V4O9 , + + niobium and tantalum are able to bond to more Nb4O10 , and Ta4O11 , which maintain oxygen atoms than that of vanadium. tetrahedral geometrical frameworks. [1] M. F. Mesleh, J. M. Hunter, A. A. Shvartsburg, G. C. Schatz and M. F. Jarrold, J. Phys. Chem., 1996,100, 16082. [2] A. Fielicke, G. Meijer and G. von Helden, J. Am. Chem. Soc., 2003, 125, 3659. [3] S. Feyel, J. Döbler, D. S. Schröder, J. Sauer and H. Schwarz, Angew. Chem. Int. Ed., 2006, 45, 4681. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Structure and thermodynamics B53 Surface Melting and Breakup of Metal Nanowires: Theory and Molecular Dynamics Simulation K. M. Ridings1, 2, S. C. Hendy1, 3 1 Department of Physics, University of Auckland, New Zealand 2 MacDiarmid Institute for Advanced Materials and Nanotechnology 3 Te Pūnaha Matatini A phenomenological Landau two-parabola model is developed to study the surface melting in metal nanowires. This has been applied to planar surfaces and spherical particles in the past [1- 3], but to the best of our knowledge not to wires, which are technologically relevant. Using this model we derive bulk melting and surface melting temperatures of nanowires, which returns the same results as classical thermodynamics. It is also seen that surface melting may play a role in the break up of metal nanowires, which has recenetly been observed [4]. Using the Landau two- parabold model developed, we derive an order parameter for a pure crystalline solid, and for a metal with a quasi-liquid layer (i.e. a surface melted nanowire). We then perturb the model at the solid-surface of the nanowire to find at what wavelengths one can expect the solid to breakup. Then in support of the theoretical models, molecular dynamics simuations are used to estimate melting temperatures with two different elements know to have different melting properties, nickel and aluminium. In nickel, the onset of anisotrpoic surface melting takes place, which then becomes more uniform as the quasi-liquid layer grows. In aluminium, it is found that while one facet completely surface melts, the lowest energy surface remains partially dry, even up to the point where the solid begins to breakup. Figure 1: Molecular Dynamics results demonstrating the constrats between the melting dynamics of two different materials. Nickel (solid = black, liquid = blue) preferrentially surface melts, while aluminium (solid = darker, liquid = lighter) only partially melts due to differences in surface energies. [1] B Pluis, D Frenkel, and JF Van der Veen. Surfaceinduced melting and freezing ii. a semi-empirical landautype model. Surface science, 239(3):282–300, 1990. [2] Hideki Sakai. Surface-induced melting of small particles. Surface Science, 351(1-3):285–291, 1996. [3] Johan Chang and Erik Johnson. Surface and bulk melting of small metal clusters. Philosophical Magazine, 85(30):3617–3627, 2005. [4] LK Wu, B Xu, QL Li, and W Liu. Self-instability of finite sized solid-liquid interfaces. Scientific reports, 5, 2015. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Structure and thermodynamics B54 Brownian motion probe for water-ethanol inhomogeneous mixture K. Furukawa1, S. Kuronuma1, K. Judai1 1 Department of Physics, College of Humanities and Sciences, Nihon University, Japan Brownian motion provides information regarding the microscopic geometry and motion of molecules, insofar as it occurs as a result of molecular collisions with a colloid particle. We investigated mixtures of water and ethanol molecules according to the Brownian motion of polystyrene beads. Figure1 shows plots of the observed mean square displacement (MSD) of pure water (a) and water-ethanol mixture (b). The calculated viscosity from the Brownian motion agrees with the liquid viscosities in pure water. However, water-ethanol sample mixtures show a discrepancy between the Brownian motion and the liquid shear viscosity. We found that the mobility of beads from the Brownian motion in a water-ethanol mixture is larger than that predicted from the liquid shear viscosity. This indicates that mixing water and ethanol is inhomogeneous in micron-sized probe beads. The discrepancy between the mobility of Brownian motion and liquid mobility can be explained by the way the rotation of the beads in an inhomogeneous viscous solvent (οߟ) converts the translational movement, 2 where <(∆x) > is the MSD, kB the Boltzmann constant, T temperature, a radius of beads, š viscosity, and t interval time, respectively. The temperature and the size dependence on the discrepancy support this equation. Figure 1: MSD of beads (a = 495 nm) as a function of the interval time for (a) pure water and (b) 20 wt% ethanol aqueous solution at 25.0 ◦C. Data plots are the observed values from the Brownian motion. The solid straight line was calculated from the macroscopic liquid viscosity. [1] K.Furukawa, K. Judai, J. Chem. Phys. 147, 244502 (2017); doi: 10.1063/1.5007813 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Structure and thermodynamics B55 Structural characterization of large thiolate-protected gold clusters and nanoparticles S.Vergara1, U. Santiago1, A. Ponce1, A. Dass2, R.L. Whetten1, M. Jose-Yacaman1 1 Department of Physics and Astronomy, The University of Texas at San Antonio, USA 2 Department of Chemistry and Biochemistry, University of Mississippi, USA [email protected] Metallic clusters and nanoparticles display unique optical, electronic, and chemical properties compared to their bulk counterparts. These properties are influenced by its internal structure. Therefore, atomic structural characterization of clusters and nanoparticles is of paramount importance in nanotechnology. The use of thiols as surface-protecting ligands has provided numerous stable clusters with atomically well-defined composition as well as small quasi- monodisperse nanoparticles. Here we present the structural analysis of two of these systems:~29 kDa pMBA-protected gold cluster and ~400 kDa hexanethiol-protected gold nanoparticles. In the former case, the structure of the cluster Au146(p-MBA)57 (~29 kDa gold core) was solved by electron diffraction to subatomic resolution (0.85 Å) and by X-ray diffraction at atomic resolution (1.3 Å) [1]. The core atoms are organized in a twinned FCC structure whereas the surface protecting motifs follow a C2 rotational symmetry about an axis bisecting the twinning plane. Au146(p-MBA)57 is the largest aqueous gold cluster solved to date as well as the smallest gold particle exhibiting a twinning plane. We also applied Pair Distribution Function (PDF) analysis to compare the new twinned FCC-structure with previous proposed icosahedral and decahedral models. Au146(p-MBA)57 structure was the most consistent structure with experimental X-ray PDF data for ~29 kDa p-MBA protected gold cluster. Optical characterization of this system showed that Au146(p-MBA)57 seems to display an incipient metallic behavior. For the case of thiolate protected nanoparticles, we present the structural characterization of ultra-small, highly monodisperse ~400 kDa (~3.8 ± 2 nm) gold nanoparticles using aberration- corrected scanning transmission electron microscopy. The High Angular Annular Dark Field (HAADF) atomic resolution images clearly showed the sample was composed of decahedral particles, including asymmetric decahedra, and FCC structures with multiple planar defects. Several nanoparticles displayed two- crystalline domains joined by a twin boundary, also known as 63 under the coincidence site lattice (CSL) notation [2]. Remarkably, we also observed nanoparticles displaying two crystalline domains with high angle misorientation corresponding to grain boundary 69. [1] S. Vergara et al., MicroED Structure of Au146(p-MBA)57at Subatomic Resolution Reveals a Twinned FCC Cluster. J. Phys. Chem. Lett. 8, 5523–5530 (2017) [2] F. J. Humphreys, M. Hatherly, F. J. Humphreys, M. Hatherly, in Recrystallization and Related Annealing Phenomena (2004), pp. 91–119. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Structure and thermodynamics B56 Synthesis and Evaluation of Water Soluble Au~250pMBA and Au~500pMBA Gold Nanoclusters. K. Sokolowska1, M. Lahtinen1, S. Malola2, L. Lehtovaara1, M. Jalasvuori3, K. Koskinen3, V. Saarnio1, P. Permi1,3, H. Häkkinen1,2 and T. Lahtinen1 Departments of 1Chemistry, 2Physics, 3biology and environmental sciences, Nanoscience Center, University of Jyväskylä, Finland Ability to sense the environment, understand and control molecules and matter in the nanoscale can be introduced to the nanostructures. In recent years we have synthesized and studied the water soluble gold nanoclusters.[1-3] Our studies have shown that the water soluble gold nanoclusters can be modified for example via ligand exchange or synthetically. In this work the synthesis to produce large water soluble gold nanoclusters, namely Au~500pMBA, with a para mercaptobenzoic acid surface as protective ligand layer was developed and characterized in comparison to Au~250pMBA cluster. The determination of the atomic structures of large sized ligand protected gold nanoclusters is still challenging. In this study several measurements and analysis, i.e. HR-TEM, Powder X-ray, NMR, UV-Vis, TG and PAGE were conducted. Instead of the 3D atomic structure, a lot of detailed information about the plausible symmetry, size, molecular composition and structure of these systems is represented some of which approaching molecular or atomic precision and resolution. Finally, the toxicity of both gold nanoclusters were investigated in various concentrations on cultures of gram-positive (Bacillus thuringiensis) and gram-negative (Escherichia coli and Klebsiella pneumoniae) bacteria. As neither of the clusters significantly inhibited bacterial growth, it appears feasible to use these clusters to develop cluster-based applications for life sciences. a) b) c) Figure 1: a) HR-TEM image of Au~250pMBA, b) HR-TEM image of Au~500pMBA, c) PAGE from Au~250pMBA and Au~500pMBA nanoclusters. [1] K. Salorinne et al. Nanoscale, 2014, 7823-7826. [2] V. Marjomäki et al. PNAS, 2014, 1277–1281. [3] T. Lahtinen et al. Nanoscale 2016, 8, 18665-18674. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Structure and thermodynamics B57 Imaging the three-dimensional shapes and lightinduced dynamics of rotating helium nanodroplets B.Langbehn1, Y.Ovcharenko1,2, D.Rupp1,11, K. Sander3, C. Peltz3, A. Clark4, M. Coreno5, R. Cucini5, P. Finetti5, M. Di Fraia5, C. Grazioli5, D. Iablonskyi6, A. C. LaForge7, V. Oliver Álvarez de Lara4, O. Plekan5, P. Piseri8, T. Nishiyama9, C. Callegari5, K. C. Prince5,10, K. Ueda6, F. Stienkemeier7, T. Fennel11,3, and T. Möller1* 1Institut für Optik und Atomare Physik, Technische Universität Berlin, 10623 Berlin, Germany 2European XFEL, 22607 Hamburg, Germany 3Institut für Physik, Universität Rostock, 18059 Rostock, Germany 4Laboratoire Chimie Physique Moléculaire, EPFL, 1015 Lausanne, Switzerland 5Elettra-Sincrotrone Trieste, 34149 Trieste, Italy 6Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan 7Physikalisches Institut, Universität Freiburg, 79104 Freiburg, Germany 8CIMAINA and Dipartimento di Fisica, Università degli Studi di Milano, 20133 Milano, Italy 9Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8501, Japan 10IOM-CNR TASC Laboratory, Basovizza, 34149 Trieste, Italy 11Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, 12489 Berlin, Germany With the advent of free-electron lasers (FEL) delivering femtosecond short-wavelength pulses, coherent diffractive imaging methods have been developed to gain insight into the structure of unsupported nanoparticles such as viruses or clusters. While experiments using light pulses in the X- ray regime ultimately aim at atomic resolution [1], full three-dimensional information on the particle shape and orientation from a single diffraction pattern requires access to wide-angle scattering signal, especially available at longer wavelengths [2]. Recent pioneering experiments on superfluid helium nanodroplets revealed strong deformations of the particles’ shape projections that were attributed to high angular momenta [3,4]. In our experiment, XUV diffraction patterns of single helium nanodroplets were recorded at the FERMI FEL's LDM endstation [5]. While the majority of the bright scattering images exhibit rings in concentric circles, thus indicating spherical droplet shapes [cf. Fig. 1(a)], about 10% of the images show diffraction patterns of non- spherical particles. In particular, a tilt of a deformed droplet out of the scattering plane producesnon-centrosymmetric features in the wide- angle diffraction pattern [cf. Fig. 1(b),(c)]. In order to simulate these features, a multi slice Fourier transform (MSFT) algorithm was employed, similar to that described in Ref. [2]. By assuming simple model droplet shapes and matching the MSFT simulations to our data, the droplets’ axes and volume could be retrieved. When compared to a numerical model of classically rotating (i.e. non- superfluid) drops [6] our data show unexpectedly good agreement. This finding is supported by recent calculations [7]. Figure 1. Top: Wide-angle scattering images of helium nanodroplets and corresponding In a second set of measurements the droplets were model droplet shapes. Bottom: Droplet doped with xenon atoms and a plasma was ignited with disintegration after IR excitation a high power infrared (IR) laser pulse. The nanoplasma propagation and destruction of the droplets was traced via single-particle imaging from femtoseconds up to hundreds of picoseconds after IR excitation [cf. Fig. 1(d)-(f)]. The reduced symmetry of the exploding particles complicates the interpretation of the diffraction patterns, demonstrating the need for 3D reconstruction algorithms. [1] K. Ayyer et al. 2016 Nature 530 202-6 [5] V. Lyamayev et al. 2013 J. Phys. B 46 164007 [2] I. Barke et al. 2015 Nat. Comm. 6 6187 [6] K. A. Baldwin et al. 2015 Sci. Rep. 5 7660 [3] L. F. Gomez et al. 2014 Science 345 906-9 [7] F. Ancilotto, et al. 2018 Phys. Rev. B. 97, 184515 [4] C. Bernando et al. 2015 Phys. Rev. B 95 064510 * [email protected] 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Structure and thermodynamics B58 Structure Evolution of Chromium-Doped Boron Clusters: Toward Formation of Endohedral Boron Cages Xin Qu,1,2,3,4 Siyu Lu,1 Lihua Yang,3,4 Jinghai Yang3,4,*and Jian Lv1,2,* 1State Laboratory for Superhard Materials, College of Physics, Jilin University, Changchun, 130012, China 2College of Materials Science and Engineering, Jilin University, Changchun 130012, China 3Key Laboratory of Functional Materials Physics and Chemistry of the Ministry of Education, Jilin Normal University, Changchun 130103, PR China 4National Demonstration Center for Experimental Physics EducationˈJilin Normal University, Siping 136000, PR China EMail/Contact Details [email protected], [email protected], [email protected] The electron-deficient nature of boron endows isolated boron clusters a variety of interesting structural and bonding properties, which can be further enriched through metal doping. In the current work, we report the structural and electronic properties of a series of chromium-doped B clusters. The global minimum structures for CrBn cluster with even number of n ranging from 8 to 22 have been proposed through extensive first-principles swarm-intelligence structure searches. Half-sandwich structures have been found to be preferred for CrB8, CrB10, CrB12 and CrB14 clusters, and transform to drum-like structure at CrB16 cluster. Endohedral cage structures with Cr atom located at the center are energetically most favorable for CrB20 and CrB22 clusters. Strikingly, the endohedral CrB20 cage has a high symmetry of D2d and a large HOMO-LUMO gap of 4.38 eV, whose stability is attributed to geometric fit and formation of 18-electron closed- shell configuration. The current results advance our understanding on the structure and bonding of metal-doped boron clusters. Keywords: First Principle CalculationˈStructure PredictionˈSmall-size Cage-like Clusters 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Nanoparticles/nanocrystals/nanostructures B59 Immobilizing horseradish peroxidase on PMA-co-PAA / chitosan nanofiber for p- nitrophenol degradation Cuie Wang, Peng Wan, Xinhua Liu, Kaiming Liao College of Textiloues and Clothing, Anhui Polytechnic University, China [email protected] Enzymes are enviro-friendly and versatile biocatalysts with high activities and superior chemo-, stereo- and region-selectivities, and the enzyme-catalyzed reactions are generally mild with low energy consumption.[1] However, the practical applications of enzymes are still subject to some restrictions, for instance, short catalytic lifespan and difficulties in reusability.[2] Immobilization of enzymes onto solid supports by physisorption and covalent attachment both provide attractive methods to overcome these limitations. [3] In this work, we demonstrate the combination of the chitosan (CTS) with PMA-co-PAA makes the electrospun membrane more biocompatible to immobilize enzyme without sacrificing its activities. The horseradish peroxidase (HRP) enzyme can be anchored onto the membrane by the formation of the covalent bond between the CTS and HRP. The immobilization parameters including CTS-, pH- and temperature-induced changes in enzyme activity have been comparatively studied to achieve high enzyme loading and stability. The enzyme membrane shows high stability over a wide pH range of 4-10 and temperature range of 25-60 oC, and long storage duration (over 35 days). Additionally, the PNP removal efficiency by the optimized enzyme membrane still retained about 70% after 10 consecutive reuses, suggesting that the chitosan-functionalized electrospun membrane may have potential applications in enzyme immobilization and environmental protection. Figure 1: Schematic representation of step-by-step immobilization of HRP on PMA-co-PAA nanofiber. [1] R. A. Sheldon, Chem. Soc. Rev., 2012, 41, 1437-1451. [2] U. Hanefeld, L. Gardossi, E. Magner, Chem. Soc. Rev., 2009, 38, 453-468. [3] C. Li, L. Zhou, C. Wang, X. Liu, K. Liao, RSC Advances, 2015, 5, 41994-41998. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Nanoparticles/nanocrystals/nanostructures B60 Rapid growth of water-dispersive CdS quantum dots D.-W. Jeong, D.-J. Jang* Department of Chemistry, Seoul National University, Republic of Korea Colloidal quantum dots (QDs), which have size-dependent band-gap energies with remarkably high quantum yields, have received great attentions [1,2]. Those intriguing properties are related to the surface states of QDs. Therefore, controlling the surface structure of QDs has been of big importance and varying the types of ligands has been often attempted as means of surface control. The synthesis of QDs usually involves organic ligands. However, it is not possible to functionalize the ligands because an organic ligand contains only one functional group with a long carbon chain. Therefore, QDs having ligands with additional functional groups have been introduced. Water-dispersive QDs have attracted a lot of interests, particularly in order to functionalize their ligands. Nowadays, diverse functionalization methods of QDs in aqueous solutions are investigated vastly. In general, ligand-exchange methods have been employed for functionalization, which requires QDs to be brought into an aqueous phase. It is inefficient to add steps to functionalize as-synthesized QDs. Thus, syntheses via aqueous routes have been often suggested. The synthesis of water-dispersive QDs in an aqueous phase has been rarely reported. Regarding CdS QDs, for example, it takes a lot of time to be synthesized in water because of the low boiling point of water. Furthermore, the Ostwald ripening (OR) growth and the oriented-attachment (OA) growth of CdS QDs have been known to occur simultaneously in the early stage. It is critical to avoid the OA growth to enhance photoluminescence (PL), but it is not possible to fully control the defect-induced luminescence of QDs synthesized through aqueous conditions. The growth mechanisms of water-dispersive CdS QDs have been investigated thoroughly. CdO and 3-mercaptopropionate ions react in water to form cadmium thiolate complexes, which transform gradually into CdS QDs in ethylene glycol at 160 °C. Absorption spectra reveal that the growth rate of CdS QDs in the first step of ≤70 s is noticeably faster than that in the second step of ≥70 s. Static and time-resolved PL spectra suggest that the dominant growth mechanism of CdS QDs switches from the OR growth in the first step to the OA growth in the second step. PL decay profiles have suggested that the fast decay time of 40 ns and the slow decay time of 300 ns are due to the decay times of excitons in internal defects (IDs) and OA-induced defects (OADs), respectively. In the first step, IDs are eliminated by the OR growth to reduce PL and the center of the PL of the slow decay component shifts from 550 nm to 600 nm as ligands dissociate to leave sulfur atoms on the surfaces of CdS QDs. In the second step, the OA growth occurs to enhance the number of OADs, increasing PL at 600 nm. Overall, the two stepwise mechanisms of the OR growth and the OA growth can be well distinguishable in a polyol solvent of ethylene glycol at a high reaction temperature of 160 °C. [1] J. Lee, Y. Kim, J. K. Kim, S. Kim, D.-H. Min, D.-J. Jang, Appl. Catal. B: Environ. 2017, 205, 433-442. [2] D. Choi, S. Ham, D.-J. Jang, J. Environ. Chem. Eng. 2018, 6, 1-8. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Nanoparticles/nanocrystals/nanostructures B61 Extraordinary stable fluorescent silicon- oxide nanoparticles in aqueous solution H. Yazdanfar1, M. M. Koç1 1 Department of Physics and Astronomy, University of Leicester, UK Stable fluorescent silicon nanoclusters are very interesting because of their low toxicity and their many possible applications in drug delivery, biological labels [1] and sensors [2] as well as applications in optoelectronic devices [3] and lasers [4]. Stable fluorescent silicon nanocluster solutions have been produced by deposition of atomic silicon on a water jet in vacuum [5]. AFM measurements show the nanoclusters produced have a size of ~1 nm. Fluorescence emission spectra depict two different fluorescence peaks at 310 nm and 420 - 440 nm; and show oxygen bands are responsible for the luminescence of the sample at longer wavelengths. As complimentary to fluorescence spectroscopy, fluorescence excitation spectra and UV/Vis absorbance spectra was measured to define the band gap of the sample which is 5.8 eV. Measurements over long time periods prove these fluorescent particles are chemically and optically stable in solution over several years without further [chemical] stabilization. Samples of silicon deposited in water jets show a fluorescence quantum yield of 8 - 10% three years after production. Nanocluster fluorescence lifetime measured at the Superlumi end station at beam I, Hasy lab, Desy, Hamburg, displays decay time of a few nanoseconds (around 3 ns). Chemical analysis of nanoparticles using XPS and ATR reveals that practically all the silicon was oxidized, and clusters produced in water are in the very high oxidation states. Infrared absorption bands were attributed to SiOH, SiH, SiO, SiO2 and SiOx, (x > 2) species. Our observations suggest that an intrinsically stable form of silicon nanocluster in water exists, and that the deep-blue fluorescence we observed emerges from oxygen-rich states. Nanoparticles that have fluorescence sites at their surface and are chemically stable would provide a promising means to reach efficient and useful bio-sensors, which is the goal in this project. References: [1] Y. He, Y. Su, X. Yang, Z. Kang, T. Xu, R. Zhang, C. Fan, S. Lee, J. Am. Chem. Soc, 131 (2009) 4434- 4438 [2] G. Wang, S. Yau, K. Mantey, M. H. Nayfeh, Optics Communications, 281 (2008) 1765 – 1770 [3] K. M. Noone, D. S. Ginger, ACS Nano, 3 (2009) 261 – 265 [4] L. Canham, Nature, 408 (2000) [5] Galinis, G., Yazdanfar, H., Bayliss, M., Watkins, M. and von Haeften, K., Towards biosensing via fluorescent surface sites of nanoparticles, J. Nanopart. Res. 14, 1019 (2012). 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Nanoparticles/nanocrystals/nanostructures B62 Co-crystallization of atomically precise metal nanoparticles driven by magic atomic and electronic shells J. Yan1, S. Malola2, C. Hu1, J. Peng1, B. Dittrich3, B.K. Teo1, H. Häkkinen2, N. Zheng1 and L. Zheng1 1Xiamen University, China ; 2University of Jyväskylä, Finland ; 3Heinrich-Heine Universität, Germany [email protected] We present analysis [1] of two novel, atomically precise, thiolate-protected silver-gold clusters found as a product of co-crystallization. The smaller cluster, (AuAg)45, is stabilized by an electron shell closing (18e) while the larger cluster, (AuAg)267, is stabilized by atomic shell closure. The smaller cluster has molecular physico-chemical properties while the larger one is clearly metallic. This observation is a first in kind and shows unambiguously that the long- discussed “competing” mechanisms to stabilize atomic clusters can in fact work in synergy in the same synthesis to produce two distinctly different products. [1] J. Yan et al., to appear in Nature Communications (2018). 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Nanoparticles/nanocrystals/nanostructures B63 A general algorithm for structure prediction of metal-ligand interfaces of hybrid nanoparticles S. Malola1, P. Nieminen2, J. Hämäläinen2, T. Kärkkäinen2, H. Häkkinen1 1 Departments of Physics and Chemistry, Nanoscience Center, University of Jyväskylä, Finland 2 Faculty of Information Technology, University of Jyväskylä, Finland [email protected] Hybrid metal nanoparticles, consisting of up to a few hundred metal atoms and more than one hundred organic capping molecules, are expected to have applications in diverse areas such as biolabeling, catalysis, medicine and solar energy. Predicting the atomic-scale structure of the hybrid nanoparticles constitutes an un-solvable optimization problem for any existing optimization method beyond system sizes of just a few metal atoms and a few ligands, due to the exponentially growing number of potential local energy minima of structural space and the complexity of chemical interactions within a single nanoparticle. However, since 2007, around one hundred crystallographically solved structures of hybrid metal nanoparticles, involving noble metals and various ligand molecules such as thiols, phosphines and alkynyls, have been reported. Combined with an ever-growing number of measurements of the physico- chemical properties of the nanoparticles, this data collectively contains valuable chemical information on the atomic bonding and structure-property relations of these nanomaterials, which could be used for successful structural predictions of yet unknown nanoparticles. In this work, we have taken the first step into this direction and devised and tested a general algorithm to predict the atomistic structure of the metal-ligand interface of thiol-stabilized gold nanoclusters Aux(SR)y by using information about the known gold-thiol chemical bonding in a set of reference structures. The algorithm was successful in predicting the observed Au-S interfacial structure for a range of different Aux(SR)y particles with (x,y) = (36,24), (38,24), (102,44), (146,57), and (279,84) starting from the known structure of the gold atoms. In addition to predicting stable interface structures, our method may prove to be useful for predicting isomers and intermediate structures during cluster transformations induced by thermal dynamics or interactions with the environment. Our algorithm is, in principle, easily modifiable for structural predictions of a large variety of hybrid nanomaterial systems once a suitable set of reference structures is identified. [1] Figure 1: Procedure to predict Au-S interface structures of protected metal nanoclusters [1] S. Malola, P. Nieminen, J. Hämäläinen, T. Kärkkäinen, and H. Häkkinen, “A general algorithm for structure prediction of metal-ligand interfaces of hybrid nanoparticles”, submitted (2018) 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Nanoparticles/nanocrystals/nanostructures B64 Plasmonic photoluminescence realized by using protectant-free Cu nanoparticle with acridine orange K. Nishio1, M. Miyagawa2, H. Tanaka2 1 Graduate School of Science and Engineering, Chuo University, Japan 2 Department of Applied Chemistry, Chuo University, Japan [email protected] Surface plasmon resonance of metal nanoparticle (NP) strongly depends on morphology as well as metal species, and gives absorption in the visible light to the near infrared region. For this reason, the corresponding emission wavelength is assumed to be shape-dependent. However, plasmonic emission has scarcely been reported experimentally, probably because relaxation process dissipates the excited energy due to interaction with protectants. In this study, protectant-free Cu NP adsorbed on saponite (Cu−Sapo) [1] was used. Saponite is one of the layered clay minerals and is known as good adsorbent of cationic dye. Since relaxation by protectant does not occur when photoexcited energy of adsorption cationic fluorescent dye transfer to Cu NP, it is expected that plasmonic emission from Cu NP is observed. In AO adsorbed on Cu−Sapo ((AO,Cu)−Sapo), two emission peaks were observed at 510 and 550 nm. In contrast, AO adsorbed on Sapo (AO−Sapo), an emission band was observed at 516 nm. In addition, (AO,Cu)−Sapo on the longer wavelength side expanded broader than AO−Sapo. When the obtained emission spectrum was fitted with a Gaussian function, the emission component was found to be three in (AO,Cu)−Sapo. However, two of them labeled as AO1 and AO2 are consistent with emission component of AO−Sapo, the unknown emission component labeled as X was observed in (AO,Cu)−Sapo .The center wavelength of X was good agreement with the plasmon absorption wavelength of Cu NP. From this, it was suggested that the excitation energy of AO is transferred to Cu NP and the one emitted was X. To support the presence of the plasmonic emission of the Cu NP, lifetime measurement was performed at 620 nm. The decay curve was fitted by two exponential curves with the lifetimes of 1.37 and 6.99 ns in (AO,Cu)−Sapo, while that was fitted by only one curve with 3.61 ns in AO−Sapo. Because the lifetime of the energy donor is generally decreased [2,3], the former value in (AO,Cu)−Sapo originates from AO, while the latter is indicative of the plasmonic emission from the Cu NP. (a) (b) Fig1. (a) Emission spectrum of (AO,Cu)−Sapo, (b)Emission decay curve of (AO,Cu)−Sapo (λem = 620 nm) [1] M. Miyagawa, A. Shibusawa, K. Maeda, A. Tashiro, T. Sugai, H. Tanaka, RSC Adv., 2017, 7, 41896. [2] J. R. Lakowicz, Analytical Biochemistry., 2001, 298, 1. [3]H.Yufan, L. Maolin, L. H. Peter. Physical Chemistry Chemical Physics., 2013, 15, 770. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Nanoparticles/nanocrystals/nanostructures B65 Graphene wraped AgInS2 flower nanocomposite with excellent visible light photocatalytic properties Lei Zhu1, Yue Chen2, Keyu Guo2, Lele Fan1, Qiangqiang Meng1 and Qinfang Zhang2,1* 1Key Laboratory for Advanced Technology in Environmental Protection of Jiangsu Province, Yancheng Institute of Technology, Yancheng, 224051, P.R. China 2School of Materials Science and Engineering, Yancheng Institute of Technology, Yancheng 224051, P.R. China [email protected] A microwave assisted hydrothermal method [1] was introduced for the synthesis of hybrid graphene-AgInS2 nanocomposite (GA). The graphene wraped AgInS2 nanocomposites were obtained, AgInS2 flower was consist of large size nanosheets. From the photocatalytic results, the excellent activity of graphene-AgInS2 nanocomposite for degradation of methylene blue (MB) and Texbrite BA-L (TBA) under visible irradiation could be attributed to both the effects of AgInS2 and charge transfer of the graphene nanosheet, and the introduction of AgInS2 to enhance the photogenerated electrons. Figure 1: FE-SEM (a) and TEM (b) micrographs of as-prepared graphene wraped AgInS2 nanocomposite. [1] Refe Wenjuan Zhang, Danzhen Li, Zhixin Chen, Meng Sun, Wenjuan Li, Qiang Lin, Xianzhi Fu, Materials Research Bulletin 46 (2011) 975–982 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Nanoparticles/nanocrystals/nanostructures B66 An in-situ method for observing the dynamic growth process of metallic nanoparticles Lei Zhang1, Long-Bing He1,2*, Lu-Ping Tang1, Li-Tao Sun1,2 1 SEU-FEI Nano-Pico Center, Key Lab of MEMS of MOE, Southeast University, Nanjing 210096, P. R. China 2 Southeast University-Monash University Joint Research Institute, Suzhou 215123, P. R. China [email protected] The growth of metallic nanoparticles is known to be related to multi-processes such as atom diffusion, migration, Ostwald ripening, coalescence, sintering, etc. [1-3] These factors are usually tangled with each other, making it difficult to uncover the dominated mechanisms underlying the growth processes. In this work, we report an in situ transmission electron microscopic (TEM) method, by which the dynamic growth processes of metallic nanoparticles can be revealed in real time. Typically, micro-sized low-melting-point metallic spheres were obtained by an ultrasonic approach and transferred onto a TEM grid. An electron beam with an intensity ranging from 0.2*104 A/m2 to 4*104A/m2 was then used to irradiate these spheres continuously to enable thermal evaporation (due to the beam heating effect) and synchronous imaging and recording. As a result, a nanoscale “evaporation and deposition” process was achieved, and the growth processes of diverse nanoparticles were able to be observed in real time. This method provides an ideal model for investigating the multi-effects during the nanoparticle growth without inducing extra factors like oxidation and contamination. Figure 1: (a) Statistically calculated nanoparticle diameters as a function of the distances to the newly grown nanoparticle and the micro-sized sphere. The inset shows the obtained diverse nanoparticles. (b)-(c) Illustration of the nanoparticle growth process of coalescence. (d)-(e) Illustration of the nanoparticle growth process of Ostwald ripening. [1] Lu, J., Low, K. B., Lei, Y., Libera, J. A., Nicholls, A., Stair, P. C., & Elam, J. W. (2014). Toward an atomically-precise synthesis of supported bimetallic nanoparticles using atomic layer deposition. Nature communications, 5, 3264. [2] Wang, Y. Q., Liang, W. S., & Geng, C. Y. (2009). Coalescence behavior of gold nanoparticles. Nanoscale research letters, 4(7), 684. [3] Liu, Y., Kathan, K., Saad, W., & Prud’homme, R. K. (2007). Ostwald ripening of β-carotene nanoparticles. Physical Review Letters, 98(3), 036102. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Nanoparticles/nanocrystals/nanostructures B67 Determining energy distribution in multiphoton absorption experiments using a time- resolved photoion imaging spectroscopy D. B. Qian1, F. D. Shi1, L. Chen2, S. Martin2, J. Bernard2, J. Yang1, S. F. Zhang1, Z. Q. Chen1, X. L. Zhu1, and X. Ma1 1 Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China 2 Institut Lumi`ere Mati`ere, UMR5306 Universit´e Claude Bernard Lyon 1 -CNRS, Universit´e de Lyon, 69622 Villeurbanne Cedex, France [email protected] We propose an approach to determine the excitation energy distribution due to multiphoton absorption in the case of excited systems following decays to produce different ion species. This approach is based on the measurement of the time-resolved photoion position spectrum by using velocity map imaging spectrometry and an unfocused laser beam with a low fluence and homogeneous profile. Such a measurement allows us to identify the species and the origin of each ion detected and to depict the energy distribution using a pure Poisson’s equation involving only one variable which is proportional to the absolute photon absorption cross section. Acascade decay model is used to build direct connections between the energy distribution and the probability to detect each ionic species. Comparison between experiments and simulations permits the energy distribution and accordingly the absolute photon absorption cross section to be determined. This approach is illustrated using C60 as an example [1]. It may therefore be extended to a wide variety of molecules and clusters having decay mechanisms similar to those of fullerene molecules. [1] D. B. Qian et al. The Journal of Chemical Physics 148 134303 (2018) 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Nanoparticles/nanocrystals/nanostructures B68 Size and Shape Controls of Protectant-free Cu Nanoparticles by Counter Anions M. Miyagawa1, A. Shibusawa2, M. Usui1, Y. Imura1, H. Tanaka1 1 Department of Applied Chemistry, Chuo University, Japan 2 Graduate School of Science and Engineering, Chuo University, Japan [email protected] Amines and carboxylic acids have been used as capping agents for anisotropic nanoparticle (NP) syntheses, while simple anions such as I− have been found to be effective recently [1]. Because anions are inevitably contained in metal salts, their effect on morphology of the NPs has attracted much attention. However, little has been known because surface of the NPs is covered with protectants. To solve this problem, we have developed a synthetic method of protectant-free CuNPs by using clay as an adsorbent [2]. Because clay is chemically and optically inactive, it helps us to understand the effect of the counter anions on the morphology. Hence, we have investigated the effect by using different copper salts and saponite as clay. When Cu(CH3COO)2 was used, diameter-controllable spherical NPs were obtained, which were composed of pure Cu without oxides [3]. The diameter control was ascribed to negatively charged layer of saponite: Cu2+ was already adsorbed before photoreduction, resulting in suppressed particle growth. In contrast, sharp-edged nanocubes (NCs) were obtained by using CuSO4 [4]. The NCs were found to be enclosed by (111) plane by HRTEM and XRD measurements. We ascribe production of the Cu NCs to disproportionation reaction of Cu2O to CuSO4 and Cu. In this reaction, the (111) plane of Cu2O was etched by H2SO4 due to large surface area, leading to the exposed plane. Thus, the morphology was found to be controlled not by capping a specific crystal plane but by etching. Changes in the morphology and oxidation state were revealed by SEM and XRD measurements, and detail production mechanisms were elucidated in relation to 2- SO4 . Figure 1: XRD patterns of the Cu NPs prepared from Cu(CH3COO)2 (left) and CuSO4 (right) with a TEM or SEM image (inset). [1] Y. Zhai, J. S. DuChene, Y.-C. Wang, J. Qiu, A. C. Johnston-Peck, B. You, W. Guo, B. DiCiaccio, K. Qian, E. W. Zhao, F. Ooi, D. Hu, D. Su, E. A. Stach, Z. Zhu, W. D. Wei, Nat. Mater., 2016, 15, 889. [2] M. Miyagawa, T. Maeda, R. Tokuda, A. Shibusawa, T. Aoki, K. Okumura, H. Tanaka, RSC Adv., 2016, 6, 104560. [3] M. Miyagawa, A. Shibusawa, K. Maeda, A. Tashiro, T. Sugai, H. Tanaka, RSC Adv., 2017, 7, 41896. [4] M. Miyagawa, M. Usui, Y. Imura, S. Kuwahara, T. Sugai, H. Tanaka, manuscript submitted. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Nanoparticles/nanocrystals/nanostructures B69 3D hot-spot engineering in gas-phase deposited Ag nanoparticles assembles for broadband SERS detection Peng Mao1, Changxu Liu 1, Wolfgang Theis1, Qiang Chen2, Min Han2 and Shuang Zhang1* 1 School of Physics and Astronomy, University of Birmingham, B15 2TT, United Kingdom 2 National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093. [email protected] [email protected] Plasmonic nanostructures possessing dense hot-spots with intense field enhancement over a large area are highly desirable for energy harvesting devices, metamaterials, photocatalysis and surface- enhanced Raman spectroscopy (SERS). SERS is an analytical tool that provides molecule- specific information on the molecule structure and composition of analytes through Raman scattering, which has been extensively studied in the past few decades [1]. In spite of the realization of high SERS enhancement factors, the maximum number of SERS hotspots for such substrates are limited to a single Cartesian plane [2,3]. Very recently, 3D plasmonic nanostructures with expansion in the third dimension are actively pursued to increase the versatility of 3D SERS platforms, by boosting the number and utility of SERS hot-spots in all three dimensions, especially along the newly extended z-axis direction [1-3]. In this study, we propose a novel 3D Ag hybrid nanostructure (3D-Ag-HNS) that contains dense plasmonic hot- spots with strong field enhancements over a large area by virtue of the flexibility of obliquely gas-phase cluster beam deposition approach. A SERS enhancement factor of is experimentally verified with high quality of uniformity and reproducibility, providing a new paradigm to realize 3D SERS substrate with high particle density. The 3D columnar plasmonic nanostructures consist of large size Ag nanoparticles and small Ag clusters aggregates. In comparison to the conventional Ag nanoparticle substrate and small Ag cluster film substrate, this nanostructure shows broad band optical response and exhibits significant improvement in sensitivity for the Raman signals, leading to remarkably cascaded optical field enhancement (CFE) accessible to the analytes. Figure1. (a) Schematic diagram of SERS measurements on 3D-Ag-HNS substrate. SERS spectra measured from the R6G-treated 3D-Ag-HNS plasmonic nanostructure and smooth Ag film (reference), the excitation laser wavelength is (b) 473 nm, (c) 514 nm and (d) 633 nm, respectively. [1] D. D. Ling, Z. L. Wu, S. J. Li, W. Q. Zhao, C. J. Ma, J. Wang, Z. M. Jiang, Z. Y. Zhong, Y. B. Zheng, and X. J. Yang, ACS Nano 11 (2), 1478 (2017). [2] H. L. Liu, Z. L. Yang, L. Y. Meng, Y. D. Sun, J. Wang, L. B. Yang, J. H. Liu, and Z. Q. Tian, Journal of the American Chemical Society 136 (14), 5332 (2014). [3] K. Jung, J. Hahn, S. In, Y. Bae, H. Lee, P. V. Pikhitsa, K. Ahn, K. Ha, J. K. Lee, N. Park, and M. Choi, Advanced Materials 26 (34), 5924 (2014). 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Nanoparticles/nanocrystals/nanostructures B70 Synthesis Mechanism of Oxide-free Cu Nanoparticles under Air R. Seki1, M. Miyagawa2, H. Tanaka2 1 Graduate School of Science and Engineering, Chuo University, Japan 2 Department of Applied Chemistry, Chuo University, Japan [email protected] Due to high catalytic activity and cost-effectiveness, Cu nanoparticles (NPs) have recently received much attention. However, because Cu NPs have low oxidation resistivity, there is a problem that an excessive amount of hazardous reducing agents is required in the chemical reduction method under air [1]. To solve this, we have reported a mild synthesis of the Cu NPs with TiO2, where oxide-free Cu NPs were obtained under air [2]. It is rather curious that the pure Cu NPs can be synthesized under air. Elucidation of this reaction may lead to the synthesis of other metals with low oxidation resistance. In the present study, we investigated the synthesis mechanism from verification of reactive oxygen species and change of XRD patterns and UV- vis extinction spectrum by UV irradiation time. When a mixed aqueous solution of TiO2, copper acetate and ethanol was irradiated by UV light, the color of the solution was changed from the air-liquid interface and turned bluish purple 2+ −● at 120 min. This result suggests that O2 involved the reduction of Cu . Because reductive O2 may be produced from O2 with an electron obtained from TiO2, a small amount of −● benzoquinone was added as the scavenger of O2 . The color of the solution was hardly changed by the UV irradiation, and an absorption band around 780 nm originating from copper acetate −● 2+ was also hardly changed. Thus, it was found that O2 reduced Cu , and O2 assists the reduction. Change of XRD patterns by UV irradiation time was measured. The peak of Cu2O at 36.4° was observed from 45 min and it was maximum at 60 min. Subsequently, the peak of Cu0 at 0 43.2° increased as the peak of Cu2O decreased and only Cu was observed at 120 min. Thus, the 2+ 0 reduction reaction from Cu to Cu was found to be sequential reaction through Cu2O. Also, in change of UV-vis absorption spectrum, an absorption band which is neither Cu2+ nor Cu NPs appeared at 550 nm from 30 min, became maximum at 45 min, disappeared at 60 min. At 60 min, this absorption band disappeared and Cu2O was maximum from XRD pattern, suggesting the existence of an intermediate giving Cu2O having absorption at 550 nm. Figure 1: UV-vis extinction spectrum of mixed solution (a) and BQ addition (b) after UV irradiation for 120 min (left) and change of XRD patterns by UV irradiation time (right). [1] S. Jeong, S. H. Lee, Y. Jo, S. S. Lee, Y.-H. Seo, B. W. Ahn, G. Kim, G.-E. Jang, J.-U. Park, B.-H. Ryu, Y. Choi, J. Mater. Chem. C, 2013, 1, 2704. [2] M. Miyagawa, T. Aoki, R. Seki, A. Shibusawa, H. Tanaka, Chem. Lett., 2017, 46, 1403. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Nanoparticles/nanocrystals/nanostructures B71 Molecular dynamics simulation of Cu film formation on Fe (001) substrate via Cu13 cluster beam deposition Huiwei Liu1, Shixu Zhang1,2, Yiwen He1, Gongping Li1,2 1 School of Nuclear Science and Technology, Lanzhou University, People’s Republic of China 2 Key laboratory of Design of Special Function Materials and Structures Ministry of Education, Lanzhou University, People’s Republic of China [email protected] (S. Zhang), [email protected] (G. Li) Cu film formation on the Fe (001) substrate via Cu13 cluster beam deposition was investigated by the molecular dynamics simulation. A many-body potential based on Finnis-Sinclair model is used to describe the interactions among atoms. The clusters containing 13 atoms of single icosahedrons structure, were deposited to ten monolayers with incident energies ranging from 0.1 to 20.0eV/atom vertically toward the Fe (001) substrate of bcc structure at various substrate temperatures (300, 700 and 1000K). The deposition rate is 1 cluster per picosecond. The simulated results showed that the incident energy of clusters play an important role in the film growth mode by analyzing the “snapshots” during the deposition process. As shown in Fig.1, the Cu clusters deposited on Fe (001) substrate mainly present the three-dimensional island growth mode (Volmer-Weber mode) at the low incident energy of clusters (൏5.0eV/atom). However, the higher incident energy of clusters shows a two-dimensional quasi-layer-by-layer growth mode (Frank-van der Merwe mode). The different temperature of the substrate can hardly affect the film growth mode. In addition, the surface roughness and the film defects are significantly decreasing as the incident energy of clusters increasing to 10.0eV/atom at temperature of 300K, but slightly increasing for higher incident energy. There is a better degree of epitaxy at low temperature (300K) and higher incident energy (2.5eV/atom). The average stress of interface are negative (tensile) at temperature of 300K and positive (compressive) at temperature of 700 and 1000K. In the conditions of the low incident energy (൏2.5eV/atom), the increasing temperature may improve film properties. In conclusion, the moderate incident energy (about 10.0eV/atom) and the low substrate temperature (300K) are suited to grow high- quality thin film with smooth, few defects, preferable degree of epitaxy and interface bonding. 0.1eV/atom 2.5eV/atom 5.0eV/atom 10.0eV/atom 20.0eV/atom Fig.1.Top view morphology of deposited 10 ML cluster atoms at incident energy of 0.1 to 20.0eV/atom and substrate temperature of 300K. Acknowledgement Supported by National Natural Science Foundation of China (No.11604129) 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Nanoparticles/nanocrystals/nanostructures B72 Multiscale Operando Simulation Methods for Supported Metal Nanoparticles B. Zhu1, Y. Gao1 1 Division of Interfacial Water and Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China. To overcome the “material gap” between the model system and the real experiments is a big challenge in the theoretical research fields. In recent works, we developed Multiscale Operando Simulation Methods for the structure reconstruction of metal nanoparticles under working conditions. Using our model, the shape evolution of various metal nanoparticles in water vapor, CO, NO, O2, H2 conditions have been quantitatively studied [1-4]. The theoretical results have extremely good consistency with experimental observations. Very recently, the changes of the perimeter interface between the supported nanoparticle and the support, which offers active sites in many reactions, has been revealed by our model coupled with operando observations [5]We will show that our model can do multiscale, quantitative, and precise predictions. The Multiscale Operando Simulation Package (MOSP) of our model is now available for download and use. Figure 1: Structure change of a 10 nm Cu nanoparticle supported on the ZnO(ͲͲͲ1) surface in water vapor environment. [1] Zhu, B.; Xu, Z.; Wang, C.; Gao, Y.; NanoLett. 2016, 16: 2628 [2] Zhu, B.; Meng, J.; Gao, Y.; J. Phys. Chem. C 2017, 121: 5629 [3] Zhang, X.; Meng, J.; Zhu, B.; Yu, J.; Zou, S.; Zhang, Z.; Gao, Y.; Wang, Y.; ChemComm. 2017, 52: 13213 [4] Meng, J.; Zhu, B.; Gao, Y.; J. Phys. Chem. C 2018, 122: 6144 [5] Duan, M.; Yu, J.; Meng, J.; Zhu, B.; Wang, Y.; Gao, Y.; Angew. Chem. Int. Ed. 2018,10.1002/anie.201800925 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Others B73 Inhomogeneity in water-alcohol mixtures by a Brownian motion K. Furukawa1, S. Kuronuma1, K. Judai1 1 Department of Physics, College of Humanities and Sciences, Nihon University, Japan The interaction between water and alcohol has been studied extensively. Because alcohol contains both hydrophilic and hydrophobic groups, mixing alcohol molecules in a water solvent generates complex networks of hydrogen bonds at molecular scale. Brownian motion provides information regarding the microscopic geometry and motion of molecules, insofar as it occurs as a result of molecular collisions with a colloid particle. In this work, the Brownian motions in water-alcohol (methanol, ethanol, and 1-propanol) mixtures are analyzed precisely. To do so, the motion of polystyrene beads (radius 500 nm) in the water-alcohol mixtures was observed and the mobility or viscosity of the liquid was calculated. Figure 1 shows a plot of calculated viscosity from Brownian motion of water-ethanol mixtures compared with macroscopic literature values (solid line). There is no discrepancy between the Brownian motion calculation and the macroscopic values for pure water (0 wt.%); however, the Brownian motion probes in water-ethanol mixtures underestimate the shear viscosity values, especially in low concentration regions. We also found the mobilities of polystyrene beads in water-methanol and water-1-propanol mixtures are larger (lower in viscosity) than those predicted from the liquid shear viscosity. This indicates that mixing water and alcohol is inhomogeneous in micron-sized probe beads. The discrepancy between the mobility of Brownian motion and liquid mobility can be explained by the way the rotation of the beads in an inhomogeneous viscous solvent converts the translation movement. Weight concentration of ethanol / wt% Figure 1: Comparison of calculated viscosity (plot) according to Brownian motion in various water-ethanol concentrations with those of macroscopic values (solid line). [1] K. Furukawa, K. Judai, J. Chem. Phys. 147, 244502 (2017); doi: 10.1063/1.5007813 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Others B74 HAADF-STEM analysis of Nano-sized precipitates in the 9Cr-1Mo-V steel subjected to high-temperature aging H. Terasaki1, Y. Miyahara2, T. Takiya2, T. Tanaka2, M. Abe2, M. Nakatani2 1 Faculty of Advanced Science and Technology, Kumamoto University, Japan 2 Hitachi Zosen Corporation, Japan The 9Cr-1Mo-V steel is known as a high-temperature steel, in which Cr and Mo are added to enhance its creep strength. Moreover, Cr improves oxidation resistance. The matrix microstructure is tempered martensite, and two types of precipitates known as the MX and M23C6 play an important role to provide the superior mechanical properties at high temperature. Additionally, the Laves phase precipitates at high-temperature aging conditions that causes aging embrittlement and significantly impacts the mechanical properties. Therefore, understanding the precipitates state of the 9Cr-1Mo-V steel at high-temperature aging is important to control its mechanical properties. In this study, two-dimensional imaging of nano-sized precipitates in the 9Cr-1Mo-V steel (weld metal and base metal) subjected to high-temperature aging is presented using HAADF-STEM analysis. The HAADF image gives a clear contrast of nano-sized precipitates, and energy dispersive X-ray spectroscopy provides the elemental maps. The key elements for the Laves phase are Mo and Si, while Nb and V for the MX type precipitates in 2D maps. Furthermore, Cr is a key element to represent M23C6. By using the technique described above, two-dimensional representation of nano-sized precipitates in the 9Cr-1Mo-V steel is obtained after high-temperature aging at 600ć for 5000 h, which is compared with the one before aging and precipitation mechanism is discussed in this study. 19th International Symposium on Small Particles and Inorganic Clusters August 12-17, 2018, Hangzhou China Author index Abe,M.: B74 Björneholm,O.: HT38 Aghakhani,Saleh: B16 Black,David M.: HT25 Aguirre,Néstor F.: HT22 Blanco-Rey,María: HT2 Ahn,Seung Joon: B15 Bódi,Dorina: B17 Akanuma,Yuki: A63,HT9 Bokhoven,J.A.van: B46 Alagia,M.: HT21 Bonačić-Koutecký,Vlasta: INV13,M1 Albaret,T.: A55 Bornhauser,P.: B46 Albertini,S.: A3 Brown,Christopher M.: B31 Alducin,Maite: HT2 Brun,Elodie: A38 Allouche,A.-R.: A55 Bülow,C.: HT16 Alonso,Julio A.: HT2,B25 Bürgi,Thomas: HT24, A38,A39, A45 Alvarez,Marcos M.: HT25 Cai,Rongsheng: B31 Amans,D.: A55 Callegari,C.: B57 Andersson,T.: HT38 Campos,A.: HT27 Ando,K.: HT6 Canty,A. J.: INV13 Antoine,R.: INV13 Chaput,F.: A55 Arakawa,Masashi: HT6,A69 Che,Jian-Tao: A26 Artmann,Evelyn: B43 Chemin,A.: A55 Asmis,K.R.: HT3 Chen,H.S.: A28,B3 Ayesh,Ahmad: A49 Chen,Ji-an: A48,A51,B7,B8 Bachs,A. Diaz: HT30 Chen,L.: B67 Baekelant,Wouter: B16 Chen,M.: A27 Baghdasaryan,Ani: A38 Chen,Minrui: A50 Bai,X.: B30 Chen,Q.: B30 Bai,Y.L.: A53 Chen,Qiang: B69 Bai,Yizhen: B36 Chen,Ruihao: B4 Bai,Yu: A62 Chen,Teng-Teng: A22 Bai,Yulong: HT26 Chen,X.: A67 Bai,Zhanbin: A73 Chen,Xi: B14 Bakker,Joost M.: HT19,HT30,B23 Chen,Xiangjun: B42 Baletto,Francesca: INV10 Chen,Xiaojie: A23 Bandelow,S.: HT23 Chen,Xiaolin: A2 Banerjee,Dipanjan: B16 Chen,Xi-Meng: INV22 Barabás,Julia: B24 Chen,Xin: A22 Barcikowski,S.: A55 Chen,Xuenian: INV22 Barnett,Robert N.: HT19 Chen,Yi-Ming: A12 Beck,Martin: B46 Chen,Yue: B65 Bernard,J.: B67 Chen,Yunhua: A48,A51,B8 Bernhardt,Thorsten M.:HT19,B28,B29,B34,B43 Chen,Z.Q.: B67 Beyer,M.: A11 Cheng,Daojian: HT12 Biasi,F.De: HT24 Cheng,Hai-Ping: HT33 Bijoy,T.K.: HT28 Cheng,Xin: A26 Bishop,Peter T.: B31 Chernyy,Valeriy: HT19,HT30 Cheung,L.F.: A8 Fennel,Thomas: INV11,B57 Chmiela,S.: B50 Fernández-Fernández,J.: B25 Choi,D.: B19 Ferrari,Piero: HT7,B22,B24 Chorkendorff,I.: HT36 Fielicke,André: INV6,HT3,HT7,B22 Clark,A.: B57 Finetti,P.: B57 Colomer,Jean-Francois: HT33 Fraia,M.Di: B57 Cooke,Kevin: B31 Fron,Eduard: B16 Coreno,M.: B57 Fu,Shuting: B5 Cornet,A.: A55 Fu,Xiaoxi: A2 Cottancin,E.: HT27 Fujimoto,S.: HT6 Cousin,F.: A39 Fukui,N.: HT35 Coutino-Gonzalez,Eduardo: B16 Furukawa,Kazuki: B54,B73 Cucini,R.: B57 Galvão,Breno: A65 Cui,Ping: HT10 Gao,Min: B5 Cui,Zhong-hua: A35 Gao,Nan: B37 Cunningham,E.M.: INV6 Gao,Yi: HT32, A24,B72 Cuong,N.T.: A14 García,A. Patricio: B51 Cuong,Ngo Tuan: B16 García-Diez,K.: B25 Czekner,Joseph: A8 Garzón,I.L.: A72,B51 D’ Acapito,Francesco: B16 Gatchell,Michael: HT29,INV19 Dai,KenJu: B54 Gell,Lars: B26 Daly,S.: INV13 Geng,Caiyun: INV12 Dass,A.: B55 Gentleman,A.S.: INV6 Debnath,S.: HT3 Gewinner,Sandy: B22 Deng,Guocheng: A4 Girod,M.: INV13 Ding,Xun-Lei: A12,A26 Gökce,B.: A55 Ding,Yanyue: B8 Gong,Shi-yan: B47 Dittrich,B.: B62 González,Pablo García: B10 Dong,P.: A24 Goulart,M.: INV19,HT29 Dong,Yi: A31 Grandjean,Didier: B1,B16 Donnelly,P.S.: INV13 Granja-DelRío,Alejandra: HT2 Du,Jifeng: HT32 Grazioli,C.: B57 Du,Qiuying: A17 Green,A.S.: INV6 Dugourd,P.: INV13 Groenhof,G.: HT31 Dujardin,C.: A55 Günther,A.: HT3 Echt,Olof: HT29 Guo,D.L.: A24 Eguchi,T.: B21 Guo,Keyu: B65 Ellis,Peter R.: B31 Guo,Ping: A44 Esch,F.: INV4 Hai,B.: A24 Fagiani,M.R.: HT3 Haija,Mohammad Abu: A49 Fan,Lele: B11,B65 Häkkinen,Hannu: HT31,A18,A70,B9,B56,B62,B63 Feifel,R.: HT21 Halder,Avik: A58 Feng,W.T.: A24 Ham,S.: B19 Hämäläinen,J.: B63 Iwe,N.: HT23 Han,Jifeng: HT34 Jalasvuori,M.: B56 Han,Ju-Guang: A68 Jamshidi,Z.: B23 Han,Min: A47,A48,A50,A51,B7,B8,B39,B69 Jang,Du-Jeon: B19,B60 Han,Yan: A61 Janssens,Ewald: HT7,HT33,A7,B1,B22 B24 Hansen,Klavs: HT7,HT21 Jeong,Dong-Won: B60 Hasegawa,Shingo: B33 Jia,Meiye: A7,B22 Hatanaka,M.: B12 Jian,Tian: A22 He,Jieting: B6 Jiang,Ling: HT1 He,Longbing: HT17,B66 Jiang,Ning: HT26,A53,A62 He,Pimo: A23 Jiang,Zhenyi: A44 He,Sheng-Gui: HT20 Jin,Chen: B7 He,Yiwen: B71 Jin,Jiaye: B44 Heiz,Ulrich: INV4 Juarez Mosqueda,Rosalba: A18 Hendy,S.C.: B53 Juaristi,J.Iñaki: HT2 Henry,Claude: HT11 Judai,K.: B73 Hillenkamp,Matthias: HT27 Jung,Julie: HT22 Hirai,Haru: HT15,A56 Kaappa,Sami: A70 Hirata,K.: A59 Kaiser,A.: INV19,HT29 Hirsch,K.: HT16 Kamigaki,T.: B2 Hofkens,Johan: B16 Kaneko,T.: B2 Höltzl,Tibor: B17,B24 Kanth,Sanjeev K.: B15 Honkala,K.: B26 Kappes,Manfred: INV2 Horioka,M.: A69 Kärkkäinen,T.: B63 Hu,C.: B62 Kartouzian,A.: INV4 Hu,Han-Shi: HT10 Kasama,Y.: B2 Hu,Jun: A54 Katsnelson,M.I.: HT30 Hu,Kuo-Juei: B1 Kawachi,K.: B2 Hu,X.Q.: A24 Kawano,T.: A69 Hu,Xinyue: A54 Kazan,rania: A45 Huang,Rao: B49 Khairallah,G.N.: INV13 Huang,Wei: B42 Kim,Dae_Wook: B15 Huang,Z.K.: A24 Kim,Ho Seob: B15 Huitema,D.J.J.: B23 Kirilyuk,Andrei: HT30 Hulkko,Eero: A43 Kitazawa,Hirokazu: HT9 Iablonskyi,D.: B57 Knall,F.: B43 Ichihashi,Masahiko: B27 Knappenberger,Kenneth L.: HT14 Imaoka,Takane: HT9,A63 Knopp,G.: B46 Imura,Y.: B68 Koç,M.M.: B61 Iskra,A.: INV6 Kociak,M.: HT27 Issendorff,Bernd von: HT16,A17,A27 Komori,M.: B21 Iwabuchi,Y.: B2 Kong,Xianglei: B48 Iwasaki,Mitsuhiro: A21 Konishi,Katsuaki: INV15,A21,A33 Koskinen,K.: B56 Li,Wan-Lu: A22 Koyasu,K.: A59,A60 Li,Yejun: A7,B1,B6 Koyasu,Kiichirou: B32 Li,Yuexing: A54 Kranabetter,Lorenz: INV19,HT29,A3,A11 Li,Zhean: B42 Kresin,Vitaly: INV18 Li,Zhongfeng: B42 Krstić,M.: INV13 Lian,Zhen: A73 Kuhn,M.: INV19,A11 Liao,Kaiming: A42,B7,B59 Kuisma,M.: B9 Liao,Ting-Wei: B1 Kumar,Vijay: HT28 Lievens,Peter: HT7,A7,B1,B6 Kuronuma,S.: B54,B73 Lindblad,R.: HT16 Kwon,Eunsang: B2 Ling,C.: B30 Lacour,Jerome: A38 Ling,Chongyi: B38 LaForge,A.C.: B57 Liu,Chang: A48,A51 Lahtinen,M.: B56 Liu,Changxu: B69 Lahtinen,T.M.: A37 Liu,Hongtao: A57 Lahtinen,Tanja: A43,B56 Liu,Huiwei: B71 Laimer,Felix: A3,A11 Liu,J.: A74 Lam,J.: A55 Liu,Shuanglong: HT33 Landman,Uzi: HT19 Liu,Xiangkai: A73 Lang,Sandra M.: HT19,B28,B29,B34 Liu,Xinhua: B59 Langbehn,B.: B57 Liu,Xin-Ran: INV22 Lara,V. Oliver Álvarez de: B57 Liu,Yiyang: A57 Latif,Mohammad Abdul: A13 Liu,Yuanjun: A46 Lau,Tobias: HT16 Logemann,R.: HT30 Laurens,Gaétan: A55 Long,La-Sheng: A52 Ławicki,A.: HT16 López,María J.: HT2,B25 Lebbou,K.: A55 Lopez-Acevedo,Olga: B14 Lechner,B.: INV4 López-Lozano,Xochitl: A72 Ledoux,G.: A55 López-Tarifa,P.: B23 Lee,L.-T.: A39 Loulou Fu: A44 Lehtovaara,Lauri: A43,B56 Lu,Hongbin: A75 Lei,M.: A27 Lu,Qian: A42 Lermé,J.: HT27 Lu,Qiliang: A16 Li,Gongping: A47,B71 Lu,Sheng-Jie: A5 Li,H.Y.: B3 Lu,Siyu: B58 Li,Hai-Ru: A1 Luo,Cuiping: B5 Li,J.: INV13 Luo,Weifeng: A50,A51,B8 Li,Jiade: B5 Lushchikova,O.: B23 Li,Jilai: INV12 Lv,Jian: A6,B58 Li,Jun: INV5,HT10,A22,A66 Ma,H.: INV13 Li,Min.: HT34 Ma,J.: HT5 Li,Qiang: B30 Ma,Lei: A17 Li,Si-Dian: A1 Ma,X.: A24,B67 Ma,Yanming: A6 Nakajima,Atsushi: M2,B21 MacAleese,L.: INV13 Nakano,Motoyoshi: HT8,A13,B35,B52 Mackenzie,Stuart: INV6 Nakatani,M.: B74 Mai,N.T.: A14 Narasimhan,Shobhana: A58 Makkonen,Esko: B14 Negishi,Yuichi: A60 Malola,Sami: HT31,A18,A70,B9,B56,B62,B63 Neumark,Daniel: INV1 Mammen,Nisha: A58 Nguyen,Minh Tho: B16,B22 Mao,Peng: B69 Nieminen,P.: B63 Mao,Wenjing: B20 Ning,Chuangang: A2,A20 Marjomäki,V.S.: A37 Nishio,Kengo: B64 Martin,S.: B67 Nishiyama,T.: B57 Martinet,C.: A55 Niu,Yubiao: HT36 Martinez,F.: HT23 Nooteboom,S.: B23 Martini,P.: INV19,HT29,A11 O’Hair,Richard: INV13 Marx,G.: HT23 Odaka,Hideho: B27 Mauracher,A.: INV19,HT29 Ogawa,yuri: A33 Mauthe,Silvia: B34 Ohshimo,K.: HT8,B35,B52 Meijer,G.: HT3 Ohshimo,Keijiro: A13 Meiwes-Broer,K.-H.: HT23 Omoda,Tsubasa: A60 Meng,Jun: HT32 Ončák,M.: A11 Meng,Qiangqiang: B11,B65 Ouyang,Yixin: B38 Meng,X.K.: A75 Ouyang,Z.W.: B3 Milani,Paolo: INV20 Ovcharenko,Y.: B57 Minamikawa,Kento: A69 Ozaki,K.: B13 Misaizu,Fuminori: HT8,A13,B2,B35,B52 Pacchioni,G.: HT36 Mishra,S.: HT6 Palmer,Richard E.: HT36,B31 Miyagawa,Masaya: B64,B68,B70 Park,Sung Jin: A17 Miyahara,Y.: B74 Patwari,G.Naresh: HT6 Mohammed,Lawal: B45 Pellarin,M.: HT27 Möller,Thomas: B57 Pellin,Michael J.: A58 Morisawa,Y.: B12,B13 Peltz,C.: B57 Moriyama,R.: HT8,B52 Peng,J.: B62 Mulder,R.J.: INV13 Peng,Xiaogang: INV9 Müller,K.-R.: B50 Perez,Danny: B49 Müller,M.: HT23 Permi,P.: B56 Mullins,S.: A72 Peters,L.: HT30 Muñoz-Castro,Alvaro: A64 Pham,H.T.: A14 Muramatsu,Satoru: B32,HT15 Pi,Xiaodong: A73 Murata,Yasujiro: INV14 Piseri,P.: B57 Murugan,P.: HT28 Plekan,O.: B57 Musa,A.: B45 Pohjolainen,Emmi: HT31 Naaman,Ron: INV17 Ponce,A.: B55 Nagata,Toshiaki: B35 Postler,J.: INV19,A11 Prince,K.C.: B57 Sels,Annelies: A39 Qi,Weihong: B6 Shao,Zongping: A42 Qian,Dongbin: A24,B67 Sharma,Anjli: B15,B45 Qiang,You: INV21 Shen,Hui: A41 Qin,Dong: HT13 Shen,Yale: A46 Qu,Guofeng.: HT34 Shi,F.D.: B67 Qu,Xin: B58 Shi,Li: B38 Radi,P.P.: B46 Shi,Ruili: A15,A19 Raspe,K.: HT23 Shi,Su-Fei: A73 Rastrelli,F.: HT24 Shibusawa,A.: B68 Reckinger,Nicolas: HT33 Shichibu,Yukatsu: A21,A33 Riccardi,L.: HT24 Sinha-Roy,Rajarshi: B10 Richter,R.: HT21 Sitja,G.: HT11 Ridings,Kannan, M.: B53 Sokolowska,Karolina: A43,B56 Roeffaers,Maarten B.J.: B16 Song,Bin: A23 Rousseau,Roger: A66 Song,Fengqi: A71,A73,B20 Ruan,Mingyue: B3 Song,X.: HT3 Ruokolainen,V.P.: A37 Song,Yan: A28 Rupp,D.: B57 Spanu,Leonardo: A58 Saarnio,Ville: A37,B56 Springborg,M.: A31 Saeed,M.A.: B45 Stienkemeier,F.: B57 Safonova,Olga V.: B1 Stranges,S.: HT21 Sai,Linwei: A19 Su,Dangsheng: B18 Salassa,Giovanni: HT24, A38,A39 Su,Tao: A57 Salén,P.: HT21 Su,Yan: A15,A19 Salorinne,K.: A37 Sugiuchi,M.: A33 Sander,K.: B57 Sun,Hailin: A36 Santiago,U.: B55 Sun,Li-Tao: B66 Sanzone,Giuseppe: A36 Sun,Xiaoyan: INV12 Sata,Ryoske: B12,B13 Suzuki,H.: B12,B13 Sauceda Felix,Huziel Enoc: B50 Szczepaniak,U.: B13 Scheerder,Jeroen E.: HT33,B1 Tadele,Kumneger: A10,B45 Scheier,P.: INV19,HT29,A3,A11 Takano,Shinjiro: HT15,A56,A59,A60,B33 Schio,L.: HT21 Takiya,T.: B74 Schlexer,Philomena: HT36,B16 Tam,N.M.: A14 Schöllkopf,Wieland: HT3,B22 Tanaka,H.: B64,B68,B70 Schütt,K.T.: B50 Tanaka,T.: B74 SCHWARZ,Helmut: INV12 Tang,Lu-Ping: B66 Schweikhard,Lutz: HT23 Tang,Rulin: A2,A20 Sebok,B.: HT36 Tchaplyguine,Maxim: HT38 Seifert,Soenke: A58,B18 Teo,B.K.: B62 Seki,Ryoya: B70 Terasaki,A.: HT6,HT16,A69 Selenius,Elli: B9 Terasaki,Hidenori: B74 Tero,T.-R.: A37 Wang,Peng: B40 Theis,Wolfgang: B69 Wang,Pengju: A15 Tiefenthaler,L.: A3 Wang,Rui: A71 Tiggesbäumker,J.: HT23 Wang,Shipeng: A21 Timm,M.: HT16 Wang,T.: HT5 Tkatchenko,A.: B50 Wang,Wen-Jie: A26 Tomihara,Ryohei: A59 Wang,Yanchao: A6 Tong,Shengfu: B5 Wang,Yizhou.: HT34 Troc,N.: HT27 Wang,Yuqing: A32 Tschurl,M.: INV4 Wei,Pei: B36 Tsukuda,Tatsuya: HT15,A56,A59,A60,B32,B33 Wei,Zhi-You: A34 Tsunoyama,Hironori: B21 Weissker,Hans-Christian: HT27,A72,B10 Tung,Nguyen Thanh: A14 Wen,Yuhua: B49 Tyo,Eric C.: A58 Whetten,Robert L.: HT25,A72,B55 Ueda,K.: B57 Wu,Bohan: A74 Usui,M.: B68 Wu,Jenna: A13 Vajda,Stefan: A58,B18 Wu,Jenna Wen Ju: HT8,B35,B52 Van der Tol,Johan: A7 Wu,Kehui: INV3 Vanbuel,J.: HT7,B22,B24 Wu,Mingmei: B5 Vergara,Sandra: B55 Wu,Qili: B5 Visscher,L.: B23 Wu,Xue: A17,A27,A32 Visser,B.: B46 Wu,Y.: A24 Vondel,Joris Van de: HT33 Xia,Younan: INV8 Voter,Arthur F.: B49 Xie,Bo: A40 Wakabayashi,T.: B12,B13 Xing,Xiaopeng: HT5 Walter,Patrick: B29 Xu,Chunkai: B42 Wan,Haiqing: A67 Xu,Cong-Qiao: A66 Wan,J-G.: A61 Xu,Haoxiang: HT12 Wan,Peng: B59 Xu,Hongguang: A5,A25,A29,A34,B40,B47 Wan,Yun: A44 Xu,Jingcai: A54 Wang,Baolin: HT37,B11 Xu,S.: A24 Wang,Chia: B41 Xu,Xiling: A5,A25,A29,B40 Wang,Cuie: B59 Xu,Zhongqi: A48,A51 Wang,G.: B44 Yacaman,Jose M.: B55 Wang,Guanghou: A73 Yadav,Anupam: B1 Wang,H.B.: A24 Yamamoto,H.: A59 Wang,Huan: A2 Yamamoto,Kimihisa: HT9,A63 Wang,J.: B30 Yamazoe,S.: A60,B33 Wang,J.G.: A24 Yan,Chao: A46 Wang,Jinlan: B38 Yan,J.: B62 Wang,Jue: B39 Yan,Juanzhu: A9 Wang,Lai-Sheng: A8,A22 Yan,S.: A24 Wang,MengMeng: A12 Yang,Bin: A5,A25,A29,B40 Yang,Bing: A58,B18 Zhao,D.M.: A24 Yang,J.: HT5,B67 Zhao,J.: A27 Yang,Jinghai: B58 Zhao,J.F.: A75 Yang,Jingling: B5 Zhao,Jijun: HT4,A15,A17,A19,A32,B36,B37 Yang,Lihua: B58 Zhao,Puju: A44 Yang,Ping: HT22 Zhao,Run-Ning: A68 Yang,Xiaowei: B37 Zhao,Shifeng: HT26,A53,A62 Yang,Y.: A74 Zhao,Yan-Xia: HT20 Yang,Y.F.: HT17 Zharinov,Vyacheslav S.: HT33 Yasumatsu,Hisato: HT35 Zhaunerchyk,V.: HT21 Yatsyna,V.: HT21 Zheng,Jiming: A44 Yazdanfar,Hanieh: B61 Zheng,L.: B62 Ye,Fen: A46 Zheng,N.: B62 Yin,B.: HT5 Zheng,Nanfeng: A4,A9,A41,B4 Yin,Feng: B20 Zheng,Weijun: HT18,A5,A25,A29,A34,B40,B47 Yin,Jinlong: A36,B31 Zhong,Yijun: A42 Yu,Q.: A74 Zhou,G.: A67 Yu,Xin: B18 Zhou,Haoshen: INV16 Yuan,Aihua: A46 Zhou,Mingfei: INV7,B44 Yuan,Peng: B4 Zhou,Q.: B30 Yuan,S.: B30 Zhou,Shaodong: INV12 Yue,Lei: INV12 Zhou,Si: A27,B36,B37 Zamudio-Bayer,V.: HT16 Zhou,Wei: A42 Zavras,A.: INV13 Zhu,Beien: HT32,B72 Zhang,Ch.: HT38 Zhu,Guoxing: A46 Zhang,Chaojiang: B40 Zhu,Lei: B11,B65 Zhang,Chen: A23 Zhu,Xiaolong: A24,B67 Zhang,J.C.: A24 Zimmermann,Nina: B28 Zhang,KangKang: A73 Zhang,Lei: B66,HT17 Zhang,Lianhua: A47 Zhang,M.: A24 Zhang,Q.: B45 Zhang,Qinfang: HT37,A10,B11,B15,B65 Zhang,S.F.: B67,A24 Zhang,Shixu: B71 Zhang,Shuai: A71 Zhang,Shuang: B69 Zhang,Xiaoben: B18 Zhang,Y.: A74 Zhang,Yafeng: B20 Zhang,Yan: A30 Zhao,Bin: HT10