Abstracts for IC’13 Oral Presentations

1

Plenary Lecture 1

The studies of selective metal recognition and metal-mediated oxidative demethylation

Chuan He

Department of Chemistry and Institute for Biophysical Dynamics, University of Chicago, Chicago 60637, USA.

Email: [email protected] . Transition metal ions are essential for many life processes. Various organisms have evolved delicate systems to control cellular metal levels and metal homeostasis. I will present our recent efforts to develop genetically encoded probes that can monitor and image cellular distributions and fluctuations of metal ions. We have also developed small molecules that specifically target cellular metal trafficking pathways. We found that these molecules exhibit remarkable activity in inhibiting cancer cell proliferation and tumor growth. The underlying mechanism will be discussed. In addition, we design proteins that can selective recognize “unnatural” metal ions. For instance, a protein selectively recognizes uranyl with exceedingly high affinity and selectivity has been developed. This protein is capable of sequestering uranyl directly from seawater. Lastly, we study iron-catalyzed oxidative demethylation in biological regulation. I will present our recent efforts to study DNA and RNA demethylation catalyzed by the mononuclear iron- and 2-ketoglutarate-containing TET family and FTO/ALKBH5 proteins, with a focus on the new RNA demethylation in biological regulation established recently in my laboratory.

2

Plenary Lecture 2

Molecular Photovoltaics and Mesoscopic Solar Cells

Michael Graetzel,

Institute of Chemical Science and Engineering Ecole Polytechnique Fédérale Lausanne CH-1015 SwitzerlandSchool of Chemistr Email: [email protected] . Learning from the concepts used by green plants photosynthesis, we have developed nanostructured systems affording efficient solar light harvesting and conversion to electricity and fuels. Solar cells using dyes or semiconducting pigment particles as light harvesters supported by mesoscopic oxide scaffolds have emerged as credible contenders to conventional p-n junction photovoltaics. Dye sensitized mesoscopic solar cells (DSSCs) were the first to employ a nanocrystalline junction and achieve currently a solar to electric power conversion efficiency (PCE) of 13%. Recently, the use of perovskite pigments as light harvesters in solid state mesoscopic photovoltaics has allowed increasing the PCE to 15 %. This impressive performance, along with excellent long-term stability has fostered first commercial applications. Some 40 companies are currently involved in industrial production serving new markets in building integrated PV and producing light-weight flexible photovoltaics.

Figure 1. left: schematic representation of a dye sensitized solar cell (DSC), right application of DSC glass panels in building facades

References 1. M. Grätzel Nature 2001,414,338. 2. A.Yella, H.-W. Lee, H. N. Tsao,1 C. Yi, A.Kumar Chandiran, Md.K. Nazeeruddin, E. W-G Diau,,C.-Y Yeh, S. M. Zakeeruddin and M. Grätzel, Science 2011 334, 629. 3. J. Burschka, N. Pellet, S.-J. Moon, R. Humphry-Baker, P. Gao, M. K. Nazeeruddin,and M. Grätzel Nature 2013 499, DOI 10.1038/nature12340.

3

Plenary Lecture 3

Activation of Small Molecules by Main Group Compounds

Philip P. Power

Department of Chemistry, University of California, Davis One Shields Avenue. Davis, CA 95616, USA

Email: [email protected] . The main theme of the lecture will be focused on how compounds derived from main group elements can effect the activation of H-H, C-H, N-H, and C-C bonds, as well as reversibly binding unsaturated molecules such as olefins or isocyanides. The lecture will focus on the reactions of a series of stable acyclic silylenes and their heavier-element congeners with ethylene (eq. 1), propene, tert-butylethylene, styrene, and norbornadiene, and the measurement of reaction energetics.

In addition, the mechanism of C-H activation by germanium and tin alkyne analogues, and by isocyanide complexes of germylenes, will be described. It will be shown that the σ-donor/π-acceptor ratio of germylenes uniquely favor the C-H activation over their silicon or tin congeners.

The long-term objective of such work is the development of catalysts based on inexpensive main group elements such as silicon or aluminum.

4

Plenary Lecture 4

Synthesis and Applications of Ordered Mesoporous Materials

Dongyuan Zhao

Department of Chemistry, Fudan University, Shanghai 200433, P. R. China

Email: [email protected]

Here, we demonstrate a surfactant-templating approach to synthesize ordered mesoporous materials with high surface area, uniform large pore size and high pore volume for the applications in energy storage and generation, biosensor and drug delivery, catalysis and water treatment. Especially, we show we demonstrate the facile organic-organic assembly approaches to synthesize ordered mesoporous phenolic resin polymers and a direct transformation to homologous carbon frameworks. A family of ordered mesoporous organic polymers and carbons are simply achieved by using commercial available cheap phenol and formaldehyde as precursors, triblock followed with a carbonization process. The mesoporous carbons have a large uniform mesopore (2 ~ 20 nm), high surface areas (800 ~ 2400 m2/g) and large pore volume (0.8 ~ 2.4 cm3/g. The mesostructures can be easily tuned from hexagonal (space group p6mm) and cubic (Im3m, Ia3d, Fd3m, Fm3m). It is interesting that by using this hydrothermal method, single crystals, nanospheres, vesicles and monoliths can be easily synthesized. For example, mesoporous carbon nanospheres with uniform diameter of 20 ~ 140 nm are fabricated through a low-concentration route. All the mesoporoes (~ 2.6 nm) are open and accessible. It shows no cytotoxicity and easily penetrates into living cells. The derived carbons with thick walls are first example of molecular sieves which have ultra high stability. We have developed some large-scale synthesis approaches, based on them, 50 Kilogrammes of ordered mesoporous carbons are easily produced in a small factory, which show potential applications in catalysis, electrochemical supercapacitors and water-treatment. The mesoporous materials reveal an excellent catalyst for the hydrocracking of heavy oil in industry such as long life (5000 hours) and high selectivity for diesel (> 85%). The mesoporous carbon show a high capacity (~ 308 F/g) and long life (> 50,000 cycles) when used as the device in small car. The mesoporous materials can also used in water treatment in industry scale.

References 1. F. Q. Zhang, Y. Meng, D. Gu, Y. Yan, C. Z. Yu, B. Tu, D. Y. Zhao, J. Am. Chem. Soc., 2005, 127, 13508; J. Am. Chem. Soc., 2007, 129, 7746; Chem. Mater., 2006, 18, 5279; Y. Huang, et al; Chem. Commun., 2008, 2641; Z. X. Wu et al, J. Am. Chem. Soc., 2010, 132, 12042; Z. X. Wu et al, Adv. Mater., 2012, 24, 458. 2. X. D. Huang, et al, Adv. Mater., 2010, 22, 833; Q. Yue et al. Angew. Chem. Int. Ed., 2012, 51, 10368-10372; Y. Wan, Y. F. Shi, D. Y. Zhao, Chem. Mater., 2008, 20, 933; D. Gu, et al, Adv. Mater., 2010, 22, 833; Y. Fang, et al, Angew. Chem. Int. Ed., 2010, 49, 7987–7991. Y. Zhai et al, Adv. Mater., 2011, 23, 4828.

5

Plenary Lecture 5

Coordination Chemistry – the Next Generation

Annie K. Powell

Institute of Inorganic Chemistry, Karölsruhe Institute of Technology, 76131 Karlsruhe Germany.

Email: [email protected] . The coordination chemistry developed by Alfred Werner at the beginning of the 20th century has evolved dramatically in recent years, fuelled partly by efforts in biomimetic chemistry seeking to model metal sites in biological systems and partly through efforts directed towards producing molecular-based systems with defined physical or architectural properties. In our recent work we have been developing the idea of the “Coordination Cluster” as a central entity in many modern coordination chemistry systems. In this lecture this approach will be illustrated using examples taken from our work and it will be shown how coordination chemistry can be used to create a variety of nanostructured materials using a bottom-up approach.[1] For example, nanoscale coordination clusters based on paramagnetic metal ions can have very large magnetic spins and show properties such as Single-Molecule Magnet behavior.[2,3] On the other hand, small coordination clusters carrying highly functionalized ligands can be used to divide space into nanoscale organic and inorganic regions[4] (Fig 1a). Such systems can be processed and often produce structured materials of the relevant oxides which can be useful new battery materials.[5] Furthernore, large coordination clusters can be used as Super Secondary Building Units (SSBUs) which can be linked by bridging ligands to give Super Metal Organic Frameworks, or SMOFs[6] (Fig 1b). Finally, relatively small ligands influence the shape and phase of mineral structures mimicking biomineralization processes[7] (Fig 1c).

Figure 1a 1b 1c

References 1. G. E. Kostakis, I. J. Hewitt, A. M. Ako, V. Mereacre, A. K. Powell, Phil. Trans. R. Soc. A, 2010, 368, 1509. 2. A. K. Powell, S. L. Heath, D. Gatteschi, L. Pardi, R. Sessoli, G. Spina, F. Del Giallo, F. Pieralli, J. Am. Chem. Soc., 1995, 117, 2491 3. A. M. Ako, I. J. Hewitt, V. Mereacre, R. Clérac, W. Wernsdorfer, C. E. Anson, A. K. Powell, Angew. Chem. Int. Ed., 2006, 45, 4926 4. W. Schmitt, J. P. Hill, M. P. Juanico, A. Caneschi, F. Constantino, C. E. Anson, A. K. Powell, Angew. Chem. Int. Ed., 2005, 44, 4187 5. W. Schmitt, J. P. Hill, S. Malik, C. A. Volkert, C. E. Anson, A. K. Powell, Angew. Chem. Int. Ed., 2005, 44, 7048. 6. M.N. Akhtar, PhD Thesis, Karlsruhe Institute of Technology, 2011 and publications in preparation. 7. S. B. Mukkamala, C. E. Anson, A. K. Powell, J. Inorg. Biochem., 2006, 100, 1128.

6

Burrows Lecture

Solar Energy Conversion – An Inorganic Chemistry ‘Wonderland’

Leone Spiccia

School of Chemistry, Monash University, Victoria 3800, Australia

Email: [email protected] . The provision of energy to the 10 billion people expected to inhabit Earth by the end of the 21st century is one of the major challenges facing the world today. The projected doubling in energy consumption over the next 50 years will lead to the rapid exhaustion of the available non-renewable energy resources, and to increases in greenhouse gases to levels that are likely to have a profound effect on the wellbeing of our planet.1 Currently, approximately 15% of our total energy consumption is met from renewable resources and concerted efforts are being made to develop new technologies further exploiting such resources. Since the amount of solar energy reaching Earth each year far exceeds that available from all other renewable sources combined, the conversion of solar radiation into electricity and fuels is seen as having the greatest potential to fulfill our future energy requirements. As inorganic and materials chemists, we have been engaging in research covering a diverse variety of topics ranging from ‘classical’ coordination chemistry to biological and medicinal inorganic chemistry (cancer diagnosis and therapy, biosensors, metalloenzyme mimics, protein purification, etc.). Over the last decade or so, my group has been placing greater emphasis on the conversion of solar energy into electricity, in particular, by dye sensitized solar cells (DSCs) and on solar water splitting, where our focus has been on materials capable of catalysing the mechanistically complex water oxidation reaction. In this presentation, I hope to convince you that these are fertile fields of endeavour for inorganic chemists by describing our recent research on: (i) the application of organometallic compounds as DSC redox couples and their utility in probing fundamental electron transfer processes occurring in the DSCs;2 (ii) exploiting the coordination chemistry of multi-dentate ligands to develop novel cobalt-based DSC redox couples;3 (iii) the application of nanoparticulate transition metal oxides as catalysts for water oxidation;4 and (iv) the coupling of such catalysts with light harvesting materials to demonstrate the potential to achieve solar water splitting.5

Figure: Depiction of a DSC showing a selection of cobalt and iron compounds that we have applied as redox shuttles (left) and photoanodes that use sunlight to achieve water oxidation (right).

References 1. N. S. Lewis, D. G. Nocera, PNAS, 2006, 103, 15729. 2. T. Daeneke T.-H. Kwon, A. B. Holmes, N. W. Duffy, U. Bach, L. Spiccia, Nature Chem., 2011, 3, 211. 3. M. K. Kashif, J. C. Axelson, N. Duffy, C. M. Forsyth, C. J., Chang, J. R. Long, L. Spiccia, U. Bach, J. Am. Chem. Soc., 2012, 134, 16646. 4. R. K. Hocking, R. Brimblecombe, S. L. Y. Chang, A. Singh, M. H. Cheah, C. Glover, W. H. Casey, L. Spiccia, Nature Chem., 2011, 3, 461; A. Singh, R. K. Hocking, L.-Y. Chang, B. M. George, M. Fehr, K. Lips, A. Schnegg, L. Spiccia, Chem. Mater., 2013, 25, 1098. 5. R. Brimblecombe, A. Koo, G. F. Swiegers, G. C. Dismukes, L. Spiccia, J. Am. Chem. Soc., 2010, 132, 2892

7

KN1A

MOFs: Nano-sized Windows into Ångstrom Space

Christian J. Doonan, Witold Bloch, Alex Burgun, Christopher Sumby.

School of Chemistry and Physics University of Adelaide, Adelaide 5005, Australia.

Email: [email protected] . Metal-organic Framework (MOFs) materials are well known for their ultra-high surface areas and gas storage and separation properties.1 One strategy for enhancing the performance characteristics of MOFs is to post- synthetically line the pores with metal ions.2 Although this technique has led to improved gas separations the precise structural characterization of the ‘metalated’ MOF has proved elusive. Here we present a novel MOF material that can be post-synthetically metalated, by a series of first and second row transition metal ions, and characterized by single crystal x-ray diffraction. Furthermore we show that inorganic transformations and oxidative addition reactions can be followed in the MOF via-single crystal to single crystal processes.

References 1. Sumida, K.; Rogow, D. L.; Mason, J. A.; McDonald, T. M.; Bloch, E. D.; Herm, Z. R.; Bae, T.-H.; Long, J. R. Chem. Rev. 2012, 112, 724-781 2. Bloch, E. D.; Britt, D.; Doonan, C. J.; Uribe-Romo, F. J.; Furukawa, H.; Long, J. R.; Yaghi, O. M. J. Am. Chem. Soc. 2010, 132, 14382-14384.

KN2A

Octahedral Ruthenium Complexes and the Cholinergic System

Nathan L. Kilah,1 Eric Meggers,2 August Smit,3 René van Elk3

1. School of Chemistry, University of Tasmania, Hobart, Australia. 2. Fachbereich Chemie, Philipps- Universität Marburg, Germany. 3. Department of Molecular and Cellular Neurobiology, Vrije Universiteit, Amsterdam, The Netherlands.

Email: [email protected]

The Australian chemist Francis P. Dwyer pioneered the use of ruthenium polypyridyl complexes as biologically active compounds. These chemically inert and configurationally stable complexes revealed an astonishing range of biological activities, such as toxicity in mice, inhibition of the enzyme acetylcholinesterase, anti-cancer activity in vivo, and bacteriostatic/bacteriocidal action. We have recently reviewed the bioinorganic work of Dwyer, prompting us to re- examine, with modern methods, the action of octahedral ruthenium complexes against the enzyme acetylcholinesterase, and more generally the cholinergic system. Dwyer’s observations of enantioselective metal cation binding to acetylcholinesterase has been confirmed by spectroscopic measurements. In addition, a new mode of interaction with an acetylcholine receptor has been identified and studied in vitro with model proteins isolated from mollusks. This newly determined mode of action has provided for new interpretations of Dwyer’s long-standing observations, and provides an explanation for the observed toxicity of polypyridyl metal complexes in vivo.

Octahedral ruthenium complexes and the cholinergic system.

Reference 1. N. L. Kilah, E. Meggers, Aust. J. Chem. 2012, 65, 1325–1332.

KN3A

Computer-Aided Materials Design for Energy Conversion and Storage

Chenghua Sun

School of Chemistry, Monash University, Clayton, Melbourne, VIC 3169, Australia

Email: [email protected]

Abstract: To improve the efficiency and success rate of materials design, large-scaled screening technology based on computational calculations and simulations has been employed extensively in the recent decade. In this talk, four examples of computer-aided materials design, including surface control of titanium dioxide for solar hydrogen production, lithium batteries, catalysts for bio-fuel production, and hydrogen storage, have been presented. Particularly, the computational capacity to investigate the ultrafast processes in photocatalysis chemistry has been demonstrated.

References 1. H.G. Yang, C.H. Sun, S.Z. Qiao, J. Zou, G. Liu, S.C. Smith, H.M. Cheng, G.Q. Lu, Nature 2008, 453, 638. 2. H.G. Yang, G. Liu, S.Z. Qiao, C.H. Sun, Y.G. Jin, S.C. Smith, J. Zou, H.M. Cheng, G.Q. Lu, J. Am. Chem. Soc. 2009, 131, 4078. 3. C.H. Sun, X.H. Yang, J.S. Chen, Z. Li, X.W. Lou, C.Z. Li, S.C. Smith, G.Q. Lu, H.G. Yang, Chem. Comm. 2010, 46, 6129. 4. C.H. Sun, D. Searles, J. Phys. Chem. C. 2012, 116, 26222. 5. Y. Jia, C.H. Sun, M.A. Wahab, L. Cheng, J. Cui, J. Zou, M. Zhu, X. D. Yao, Phys. Chem. Chem. Phys. 2013, 15, 5814. 6. L. Wu, H.B. Jiang, C.H. Sun, H.G. Yang, Chem. Comm. 2013, 49, 2016.

KN1B

Programmed Pore Architectures in Modular Metal-Organic Frameworks

Shane G. Telfer, and Lujia (Luke) Liu

MacDiarmid Institute of Advanced Materials and Nanotechnology, Massey University, Palmerston North, New Zealand.

Email: [email protected] . This talk will present a general strategy for generating metal-organic frameworks (MOFs) that are complex yet well ordered. A set of topologically distinct linkers that codes for the assembly of a highly porous quaternary MOF has been developed. Since the different linkers are located in predetermined positions in the crystalline lattice, functional groups appended to analogs of these ligands are consequently located in predefined positions in the MOF pores. A set of frameworks is produced in which pore architectures are systematically varied while the topology is maintained. We term these materials programmed-pore MOFs (PP-MOFs). It is notable that PP-MOFs engender high complexity while circumventing the pore inhomogeneity that is inherent to MOFs that are constructed from an isostructural set of linkers. PP-MOFs are capable of complex functional behaviour including CO2 sorption trends that emerge from cooperative interactions between the ligands.

KN2B

Molecular imaging tools for intracellular redox state

Matthew D. Anscomb, Amandeep Kaur, Jonathan Yeow, Elizabeth J. New

School of Chemistry, The University of Sydney, 2006, Australia.

Email: [email protected]

Disturbances in the redox potential of biological systems have wide-ranging effects, disrupting signaling pathways and contributing to disease. Oxidative stress is particularly important in diseases of ageing, such as cardiovascular disease, diabetes, obesity and neurodegenerative diseases. Despite these important links between oxidative stress and disease, there are not good methods for measuring the oxidative stress within a cell.

We are interested in designing small molecule sensors to probe redox state within cells. Our probes utilise biologically- derived groups as the sensing moieties, and signal changes in redox state by ratiometric changes in fluorescence or modulation of magnetic resonance (MR) contrast.

In particular, we have developed the first reversible, redox-responsive MR contrast agent, RG1, based on the commonly-used Gd-DO3A scaffold and a riboflavin sensing group. RG1 exhibits a two-fold increase in relaxivity (r1) upon oxidation, due to a change in the hydration state of the metal. The probe operates at biologically-relevant reduction potentials, is able to detect changes in oxidised to reduced glutathione at cellular ratios, and gives measurable changes in phantom images of the complex in a commercial MRI machine. We are now developing probes which utilise the inherent fluorescence of the flavin, allowing us to perform dual fluorescence-MR imaging.

We have also demonstrated useful strategies for reversible fluorescent redox sensors, which are fluorescent in oxidised form and non-fluorescent when reduced. We are using these sensors in cellular studies, and developing further analogues with modulated reduction potentials and fluorescence output.

KN3B

The Mechanism of Ethylene Dimerisation with the Ti(ORʹ)4/AlR3 Catalytic System: Combined Experimental and DFT Studies

David McGuinness, James Suttil, Robert Robinson Jr and Brian Yates

School of Chemistry, University of Tasmania, Hobart 7001, Australia.

Email: [email protected] . Ti-alkoxide based catalysts in combination with AlEt3 are responsible for the production of a significant proportion of the world’s 1-butene supply, via the dimerisation of ethylene. A metallacycle mechanism is normally presumed to operate with this system.1 However, despite its importance, the catalyst is not mechanistically well understood. The mechanism of dimerisation has been studied through a series of C2H4/C2D4 co-oligomerisation experiments and comparison of theoretical and experimental mass spectra. The results obtained show that the textbook metallacycle mechanism is most likely not responsible for dimerisation with this catalyst.2 Instead, an excellent fit between the theoretical and experimental mass spectra is obtained when a conventional Cossee-type mechanism (insertion/β-hydride elimination) is modeled. The formation of both the primary product 1-butene, and the secondary reaction products (ethylene/1-butene co-dimers) are best explained by this mechanism. The experimental findings are further supported by DFT analysis of both mechanistic routes on a number of model catalysts.

Ti Ti ? Ti Ti H

References 1. A. Forestière, H. Olivier-Bourbigou, L. Saussine, Oil & Gas Sci. Tech. Rev. IFP 2009, 64, 649 2. J. A. Suttil, D. S. McGuinness, Organometallics 2012, 31, 7004 3. R. Robinson Jr, D. S. McGuinness, B. F. Yates, submitted for publication, 2013.

KN4A

Self-Assembly of Metallo-Supramolecular Cubes: Design, Synthesis and Guest Discrimination

Jack K. Clegg,a,b William J. Ramsay,b Wenjing Mengb and Jonathan R. Nitschkeb

aSchool of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, 4072, Australia. bDepartment of Chemistry, The University of Cambridge, Cambridge, CB2 1EW, UK.

Email: [email protected] . The self-assembly of multi-nuclear metallosupramolecular architectures has received significant recent attention due to any potential applications in host-guest chemistry and catalysis.1 The programmed formation of these beautiful and complex systems generally results from the combination of the inherent geometric, electronic and steric information present in each of the metallic and organic components.2 Despite the ever-increasing number of such assemblies, there are relatively few examples of cubic structures in the literature.3 We have recently prepared a number of cubic architectures that encapsulate substational volumes. By changing their properties through the variation of ligand elements we have been able to vary the guest-binding properties of these materials. For example, the inclusion of π-rich porphyrin groups on the faces of the cages allows the selective binding of fullerenes4, the preparation of a cage with “open” faces allows for solvent dependent host-guest chemistry5 and the use of molydebnum “paddle-wheels” results in a cage that allows the anion-association to be tuned bidirectionally.6

References 1. (a) B. Breiner; J. K. Clegg; J. R. Nitschke Chem. Sci. 2011, 2, 51(b) R. Chakrabarty; P. S. Mukherjee; P. J. Stang Chem. Rev. 2011, 111, 6810. 2. N. J. Young; B. P. Hay Chem. Commun. 2013, 49, 1354. 3. M. H. Alkordi; J. L. Belof; E. Rivera; L. Wojtas; M. Eddaoudi Chem. Sci. 2011, 2, 1695. 4. W. Meng; B. Breiner; K. Rissanen; J. D. Thoburn; J. K. Clegg; J. R. Nitschke Angew. Chem., Int. Ed. 2011, 50, 3479. 5. C. Browne; S. Brenet; J. K. Clegg; J. R. Nitschke Angew. Chem., Int. Ed. 2013, 52, 1944. 6. W. J. Ramsay; T. K. Ronson; J. K. Clegg; J. R. Nitschke Angew. Chem., Int. Ed. 2013, in press.

KN5A

Probing selectivity in the iron containing extradiol dioxygenases

Gemma J. Christian, Shenga Ye and Frank Neese

School of Science and Mathematics, Avondale College of Higher Education, Cooranbong, 2265, Australia.

Email: [email protected] .

Non-heme enzymes play vital roles in numerous biological oxidation pathways, as diverse as growth regulation in plants to the breakdown of aromatic compounds in the soil by bacteria. Catecholate dioxygenases form a part in the latter process by catalysing the C-C bond cleavage and ring opening of catecholates.1,2 The aromatic ring of the substrate can either be opened between the two hydroxyl groups, which is known as intradiol cleavage, or to one side, which is referred to as extradiol cleavage. Despite decades of study the factors which control the selectivity for intradiol or extradiol behaviour are still an intriguing puzzle. The active site of extradiol enzymes usually consists of an iron(II) centre coordinated by two histidine ligands and a carboxylate group, a common motif in the non-heme enzyme super-family. Intradiol active sites in contrast have a two- histidine, tyrosine binding mode and utilise an FeIII active site, along with a different coordination geometry. Although it would be tempting to ascribe the enzyme selectivity to the differences in the active site and metal oxidation state, a His200Asn mutant of the extradiol enzyme homoprotocatechuate 2,3-dioxygenase (HPCD) was found to perform intradiol ring opening of a modified substrate DHB.3 This was the first time that an extradiol enzyme had been induced to show intradiol behaviour. Here we extend earlier studies on the mechanism and reactive species of HPCD using computational methods4 and investigate the way in which the coordination environment of the metal in the active site controls selectivity in the extradiol enzyme. The coordination of the substrate to the metal and the hydrogen bonding network with second sphere residues were found to play key roles in controlling the selectivity of the substrate ring opening steps.

Figure 1. Ring opening by catecholate dioxygenases may occur in two positions.

References 1. M. Costas, M. P. Mehn, M. P. Jensen and L. Que, Jr., Chem. Rev., 2004, 104, 939-986. 2. F. H. Vaillancourt, J. T. Bolin and L. D. Eltis, Crit. Rev. Biochem. Mol. Biol., 2006, 41, 241-267. 3. S. L. Groce and J. D. Lipscomb, J. Am. Chem. Soc., 2003, 125, 11780-11781. 4. G. J. Christian, S. Ye, and F. Neese, Chem. Sci., 2012, 3, 1600-11.

KN6A

C-F activation in Lanthanoid Formamidinates

Peter C. Junk, Glen B. Deacon and Daniel Werner

School of Pharmacy & Molecular Sciences, James Cook University, Townsville 4811, Australia.

Email: [email protected]

We have been interested in using lanthanoid complexes in the C-F activation chemistry of organic molecules.1,2,3 We are now using fluorinated formamidines as supporting ligands in this chemistry and we find that these compounds can also C-F activate under certain conditions. In this talk we will present the synthesis of these compounds, and the variable C-F activation chemistry with respect to metals, ligands and conditions.

[La(CF3Form)3] CF activation precursor C-F Activation product

References 1. M.L. Cole, G.B. Deacon, P.C. Junk and K. Konstas, Chem. Commun., 2005, 1581-3. 2. G.B. Deacon, C.M. Forsyth, P.C. Junk and J. Wang, Chem. Eur. J., 2009, 15, 3082-92. 3. G.B. Deacon, C.M. Forsyth, P.C. Junk, R.P. Kelly, A. Urbatsch and J. Wang, Dalton Trans., 2012, 41, 8624-34.

KN4B

d6 metal complexes for tumour-selective drug delivery

Anna Renfrew, Nicole Bryce and Trevor Hambley

School of Chemistry, University of Sydney, Sydney, 2006, Australia.

Email: [email protected] . The majority of potential and clinically used anticancer therapeutics are affected by problems such as poor pharmacokinetics, low selectivity for tumour cells and limited accumulation in large tumours. Rather than seeking to redesign or abandon such compounds, a promising strategy to overcome these limitations is to use a drug delivery system. Transition metal complexes are a versatile platform for drug delivery, with a wide range of potential ligands and oxidation states accessible at physiological pH. Through judicious choice of ligands, the lipophilicity/hydrophilicty of a complex can be tuned, in addition to its electronic properties, pKa and reduction potential. Furthermore, as metal- ligand bonds are highly sensitive to environment, selective mechanisms for drug release can be incorporated. We have developed a number of cobalt(III) and ruthenium(II) complexes capable of forming inert prodrug complexes with hydroxyketone, imidazole, pyridine and triazole-based drugs. The prodrugs can be activated in tumour cells by visible light or reduction, yielding up to a 50-fold increase in cell death. Using a combination of techniques including fluorescence lifetime imaging and X-ray absorption spectroscopy, we can observe the release of the active drug in cells and gain an understanding of the fate of the metal complex.

Reference 1. A. K. Renfrew, N. S. Bryce, T. W. Hambley, Chem. Sci. 2013, 4, 3731.

KN5B

Synthesis and characterization of targeted luminescent lanthanide complexes for live cell imaging applications

Sally E. Plush, Robert Brooks and Zhangli Du

School of Pharmacy and Medical Sciences, University of South Australia, Adelaide 5005, Australia.

Email: [email protected]

Targeted live-cell imaging technologies which can selectively visualise biological processes are in high demand. The application of luminescent lanthanide ion complexes to cellular imaging has led to the generation of probes, where the signal can be easily resolved from background fluorescence, and photobleaching is significantly minimised. Lanthanide ion probes are potentially ideal for live cell imaging due to their small size and long emission lifetimes. To date luminescent lanthanide ion complexes have been internalized into sub cellular compartments.1-4 The challenge in the field is to control both the method of internalisation and the targeting of these probes towards specific organelles. Therefore, the first priority is to systematically study the effect of structural changes on probe uptake and emission intensity, thereby identifying critical parameters in probe design. Herein, we report the synthesis and characterisation of a series of new luminescent lanthanide (Ln(III) = Eu(III) and Tb(III)) ion complexes coupled a range of biological targeting motifs (Figure 1 shows one example of a highly emissive Tb(III) ion complex targeted to the folate receptor). The emission properties of the molecular probes at different pHs, the emission lifetimes, and the number of metal bound water molecules have been defined in solution. The results from cellular uptake and localisation studies of the molecular probes in a variety of insect and mammalian cells have highlighted several key features of probe design.

O HO O O O O H N O N N OH N N H H O N O Tb(III) O N N H N N N N O N N NH2 H H O O

Figure 1 Left: The structure of a Tb(III) ion folate receptor targeted probe and Right: the visible emission of the probe dissolved in a minimal amount of 20 mM phosphate buffer and diluted to 5 x 10-5 M by H O at then imaged using a benchtop UV light (  254 nm). 2 ex

References 1. Puckett, C. A.; Ernst, R. J.; Barton, J. K. Dalton Trans. 2010, 39, 1159-1170 2. Montgomery, C. P.; Murray, B. S.; New, E. J.; Pal, R.; Parker, D. Acc. Chem. Res. 2009, 42, 925-937 3. Manning, H. C.; Goebel, T.; Thompson, R. C.; Price, R. R.; Lee, H.; Bornhop, D. J. Bioconjugate Chem. 2004, 15 4. Chauvin, A.-S.; Comby, S.; vandevyer, C. D. B.; Bünzli, J.-C. G. Chem. Eur. J. 2008, 14, 1726-1739

KN6B Nanoscale inorganic materials for energy applications

Shi Xue Dou

Institute for Superconducting and Electronic Materials, Australian Institute of Innovative Materials University of Wollongong, Squires Way, Northwollongong, NSW, Australia

E-mail: [email protected]

In this talk, I will show that very special properties or new discoveries are generated via a capability to manage two completely opposite elements or phenomena to co-exist at scale in one system. Superconductivity and magnetism are antagonistic phenomena but when these are manipulated to co-exist at lattice scale, a very strong pinning force results to pin the magnetic fluxes, leading to record high pinning potential and hence high field performance of the superconductor for applications. Co-existence of a carbon modified surface and untouched interior at nanoscale leads to a breakthrough in high field critical current density of MgB2 superconductors. Co-existence of phonon glass and electron crystal in thermoelectric materials achieved by multi-scale scattering resulted in an ideal state for increasing figure of merit to effectively covert waste heat to electricity. Combination of active and inactive materials in energy storage systems is the best strategy to ensure high electrochemical reactivity and structural integrity. A coexistence of body insulator and surface gapless conductor has led to the discovery of a completely new class of material: topological insulators with extraordinary properties. A combination of 1D and 3D structured TiO2 leads to high conversion rate of DSSC.

References 1. Z.Q. Sun et al.,Chem. Commun., 49 (10) 966-968 (2013) 2. Z.J. Yue et al.,Nanoscale, 2013, 5, 9283 3. X.L. Wang et al., Phys. Rev. Lett. 108 (26) 266806 (2012) 4. JH Kim et al Adv. Mater. 23, 4942-4946 (2011) 5. Z.Q. sun et al., J. Amer. Chem. Soc., (2011) 6. P Jood et al., Nano Lett. 11, 4337 (2011) 7. WK Yeoh et al., PRL 106, 247002 (2011) 8. SX Dou et al PRL, 98 (2007) 97002 9. SL Chou et al J. Mater. Chem., 2010, 20, 2092–2098

KN7A

8+ Host-Guest and Spin Crossover Behaviour in Face-capped [Fe4L4] Tetrahedral Cages

Paul E. Kruger,1,2 A.W. Ferguson,1 M.A. Squire,1 C.M. Fitchet,1 B.E. Williamson,1 R. Clérac,3 and C. Mathonière4

1Department of Chemistry, University of Canterbury, Christchurch, New Zealand. 2MacDiarmid Institute for Advanced Materials and Nanotechnology, Department of Chemistry, University of Canterbury, Christchurch, New Zealand. 3CNRS, Centre de Recherche Paul Pascal and Université de Bordeaux, Pessac, France. 4CNRS, Institut de Chimie de la Matière Condensée de Bordeaux and Université de Bordeaux, France.

Email: [email protected]

The self-assembly of molecular cages has produced an impressive array of species of varied shapes and sizes capable of encapsulating guests within their internal cavities [1]. The interior of these capsules has been employed to: catalyze reactions; protect otherwise unstable molecules; and selectively bind guest molecules. Some of the best studied examples are the tetrahedral molecular cages [2]. The remarkable host-guest properties of these molecular containers inspired us to explore the possibility of incorporating Fe(II) spin crossover (SCO) centres into these capsules. SCO has been observed in a wide range of architectures including discrete complexes, polymers, and networks [3]. Binding of guest molecules in these modified capsules could produce significant variation in magnetic properties. Despite this fascinating link between host-guest interactions and SCO behaviour, the synthesis of SCO molecular capsules capable of binding guest molecules is limited [4].

Presented here are Fe(II) molecular tetrahedra that form through self-assembly of stoichiometric amounts of the ligand 8+ sub-components and Fe(II) to afford the face-capped [Fe4L4] tetrahedra. Notably, these nano-containers display magnetic and optical responses to a range of external stimuli, including temperature, light, and solvent molecules. Significantly, the fully reversible, abrupt, total spin crossover from high-spin to low-spin is centred around a T1/2 ≈ 285 K in the solid-state. Of particular importance is its ability to switch fully and abruptly between high-spin and low-spin forms in dilute solution. We will present details of their host-guest, spectroscopic and magnetic behaviour.

Acknowledgements: The authors thank Royal Society of New Zealand Marsden Fund and The MacDiarmid Institute for Advanced Materials and Nanotechnology for financial support.

References 1. M.D. Ward, Chem. Commun., 2009, 45, 4487. 2. J. K. Clegg, F. Li, K.A. Jolliffe, G.V. Meehan and L.F. Lindoy, Chem. Commun., 2011, 47, 6042. 3. M.A. Halcrow, Chem. Soc. Rev. 2011, 40, 4119-4142. 4. P.E. Kruger, A.W. Ferguson, M.A. Squire, D. Siritanu, D. Mitcov, C. Mathonière, R. Clérac, Chem. Commun., 2013, 49, 1597-1599.

KN8A

Adventures in the coordination chemistry of iodine

Jason L. Dutton

Department of Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, Australia.

Email: [email protected] . Coordination chemistry for the halogens, where a halogen acts as the Lewis acid, is underdeveloped compared to the other groups in the periodic table with the exception of the Noble gasses. This largely stems from a lack of suitable, Lewis acidic, high oxidation state precursors for F-Br. Iodine is a notable exception, as high oxidation state interhalogens such as ICl3 are relatively stable, and could be viewed as a Lewis acidic iodine centre. Our interests lie in exploring the fundamental coordination chemistry of this, and related I(III) species, in particular PhI(OTf)2 and [PhI(pyr)]2+ as Lewis acidic centres (OTf = triflate, pyr = pyridine). This presentation will describe our initial forays into this area, including the first example of a classic ligand exchange reaction at iodine and also the use of these compounds as oxidants for the isolation of high oxidation state late transition metal complexes.

Reference 1. T. P. Pell, S. A. Couchman, S. Ibrahim, D. J. D. Wilson, B. J. Smith, P.J. Barnard, J. L. Dutton, Inorg. Chem. 2012, 51, 13034-13040.

KN9A

Flexible Dye Sensitized Solar Cells on Plastic Substrates

Yi-Bing Cheng1, Fuzhi Huang1, Hasitha Weerasinghe1, Yang Chen1, Yu Han1, Alex Pascoe1, Yasmina Dkhissi2, Dehong Chen2, Rachel A. Caruso2,3

1Department of Materials Engineering, Monash University, Clayton 3800, Australia. 2School of Chemistry, The University of Melbourne, Melbourne, Victoria 3010, Australia. 3CSIRO Materials Science and Engineering, Clayton South, Victoria 3169, Australia.

Email: [email protected]

Dye sensitised solar cell (DSSC) is an attractive renewable energy technology due to its relatively low material and manufacturing costs. DSSC devices made on plastic substrates are particularly interesting for their flexibility, lightweight, easy to handle and transport and more adaptable to continuous roll-to-roll processing. There are technical difficulties in fabricating DSSCs on plastics, resulting in lower conversion efficiency compared to their glass based counterparts. A major challenge for making DSSCs on plastic substrates is the difficulty in making good quality porous TiO2 films as working electrodes because plastic substrates could not be heated to high temperatures, which is necessary to build up chemical bonding between TiO2 particles for electron transport. Several low-temperature fabrication methods have been investigated, including ball-milling, acid treatments, microwave irradiation, and different mechanical compression techniques. Among these processes, the cold isostatic pressing (CIP) was the most effective approach for achieving high efficiency devices. The applied isostatic pressure improved the compaction between TiO2 nanoparticles and the contact between the TiO2 film and the ITO substrate, which reduced the electrical resistivity of the working electrode. However, our recent study found that the compression technique could only improve the short-term photovoltaic performance of the devices, and their long-term stability was gradually degraded due to gradual relaxation of particle-particle contacts and particle-conductive layer contacts. On the other hand, submicrometer- to micrometer-sized nanostructured mesoporous TiO2 spheres were found to be a unique material for plastic based DSSCs. These spheres were calcined at 500°C after a combined sol-gel and solvothermal synthesis process, resulting in good chemical bonding between the nano particles inside the spheres. Working electrodes made of the mesoporous spheres as building blocks have only a very small fraction of the particles unsintered. This is a significant improvement overcoming the intrinsic temperature limitation of plastic substrates. With these spheres, a high power conversion efficiency of 7.5% was achieved for plastic based flexible DSSCs. On the manufacturing side, progress has been made in the development of continuous printing technologies. A major project of the Victorian Organic Solar Cell Consortium (VICOSC) has developed a continuous screen-printing line that is capable to print up to 300x300 mm DSSC modules on plastics at Monash University.

KN7B Hydrogen storage materials: Designing for success

Kondo-Francois Aguey-Zinsou

Merlin group, School of Chemical Engineering, University of New South Wales, Sydney 2052, Australia.

Email: [email protected] . Storing hydrogen in materials is based on the observation that metals can reversibly absorb hydrogen. However practical application of such a finding has found to be rather challenging especially for vehicular applications. The ideal material should reversibly store a significant amount of hydrogen under moderate conditions of pressures and temperatures. To date, such a material does not exist and the high expectations of achieving the scientific discovery of a suitable material simultaneously with engineering innovations are out of reach. Of course, major breakthroughs have been achieved in the field, but the most promising materials still bind hydrogen too strongly and often suffer from poor hydrogen kinetics and/or lack of reversibility. Clearly, new approaches have to be explored, and the knowledge gained with high-energy ball milling needs to be exploited, i.e. particle size does matter! The properties of nanomaterials are known to be size depend. Such size depend effect could offer powerful means to finally control both the thermodynamic and kinetic properties of hydride materials at the molecular level.

Here, the potential of this new approach1 and the major breakthroughs we have achieved in recent years through nanosizing will be discussed. In particular, the effects of particle size restriction on some of the most promising hydrogen storage materials, i.e. magnesium and borohydrides, will be reported. Hence, through particle size restriction full desorption of hydrogen, i.e. 7.6 mass % of hydrogen, was achieved at 85 °C with colloidal magnesium (Fig. 1A) 2 instead of the usual 400 °C required for bulk magnesium. Similarly, core-shell NaBH4@Ni nanoparticles (Fig. 1B) 3 demonstrated for the first time the possibility of reversibly storing hydrogen under practical conditions with NaBH4, a compound that irreversibly decomposes into its elements at temperatures > 500 °C.

2 3 Fig. 1: (A) magnesium nanoparticles and (B) core-shell NaBH4@Ni reversibly storing hydrogen at unprecedented temperatures.

References 1. Aguey-Zinsou, K.F.; Ares Fernandez, J.R. Energy Environ. Sci., 2010, 3 (5), 526-543. 2. Ares Fernandez, J.R.; Aguey-Zinsou, K.F. Chem. Mater., 2008, 20 (2), 376-378. 3. Christian, M.; Aguey-Zinsou, K.F. ACS Nano, 2012, 6(9), 7739-7751.

KN8B Quinoline- and Isoquinoline-based N3 Ligands and Complexes

Nigel T. Lucas, Matthew C. Smart and Mona Alamri

Department of Chemistry, University of Otago, Dunedin 9016, New Zealand

Email:[email protected]

Complexes of chelating N-heteroaromatic ligands, in particular 2,2′-bipyridine and 2,2′:6′,2″-terpyridine, have been widely used as building blocks in coordination and supramolecular chemistry.1,2 Terpyridines have a high binding affinity towards a range of metals ions across a number of oxidation states. The robust nature of terpyridine-based materials has led to the study of their photophysical, electrochemical and magnetic properties, for applications including photovolatics, light-emitting devices and non-linear optical devices. In addition to these materials goals, the biomedical, pharmaceutical (e.g. DNA binding), and catalytic activity of such complexes are areas of significant interest.2 The multiplicity of applications related to terpyridines and their metal complexes calls for high structural diversity. One approach to tuning terpyridine ligands is the annulation of aromatic rings to the basic subunit; simple analogues of terpyridines containing quinolines and isoquinolines have been previously reported.3-5 As part of our study to prepare tweezer molecules6 with large aromatic pincers that can close in the presence of a suitable guest, we have turned to quinoline- and isoquinoline-based hinge units. This has entailed the development of reliable routes into heterocycles appropriately functionalised for incorporation into N3 ligands, and the coupling of the aryl pincer groups late in the synthesis. Progress toward the synthesis of large tweezer molecules based on quinoline and isoquinoline units will be reported, along with the demonstration of their ability to coordinate transition metals.

References 1. C. Kaes, A. Katz, M. W. Hosseini, Chem. Rev. 2000, 100, 3553. 2. A. Wild, A. Winter, F. Schlütter, U. S. Schubert, Chem. Soc. Rev. 2011, 40, 1549. 3. A. Mamo, A. Juris, G. Calogero, S. Campagna, Chem. Commun. 1996, 1225. 4. E. Largy, F. Hamon, F. Rosu, V. Gabelica, E. De Pauw, A. Guédin, J.-L. Mergny, M.-P. Teulade-Fichou, Chem. Eur. J. 2011, 17, 13274. 5. N. Onozawa-Komatsuzaki, M. Yanagida, T. Funaki, K. Kasuga, K. Sayama, H. Sugihara, Inorg. Chem. Commun. 2009, 12, 1212. 6. M. Hardouin-Lerouge, P. Hudhomme, M. Sallé, Chem. Soc. Rev., 2011, 40, 30.

KN9B

Structure, reactivity, electrochemistry, and spectroscopy of metallic intermediates in controlled gaseous environments W. Alex Donald

School of Chemistry, University of New South Wales, Sydney 2052, Australia.

Email: [email protected].

Reactive intermediates are of fundamental importance to the outcomes of many chemical transformations. For example, high-valent iron(IV)-oxo and iron(V)-oxo species are implicated as important intermediates in the catalytic cycles of non-heme enzymes that selectively functionalize aliphatic C-H bonds at ambient conditions. However, these intermediates are challenging to isolate and characterize because they are short lived and formed in low abundance in the presence of more abundant species. One strategy for studying reactive intermediates is to form and investigate such species in the gas phase, where they can (i) be individually isolated from all other ions, solvent, and impurities that can react with and destroy the species; or (ii) formed in composition-controlled clusters that contain a discrete and well-defined number of solvent molecules, counter-ions, active metal-centres etc. (for example, see [1-5]). Here, ongoing efforts to synthesize and characterize the structure and reactivity of a series of novel and reactive biomimetic high-valent iron-oxo ions using ion- molecule reactions, UV/VIS laser ion action spectroscopy, and other advanced mass spectrometry methods are reported. These results suggest that the presence of an intact iron(IV)-oxo unit in ligated coordination complex ions can be rapidly determined using gaseous ion-molecule reactions and ion spectroscopy methods. We anticipate that these approaches will be broadly beneficial for characterizing many types of reactive metal-oxo intermediates that are challenging to isolate and characterize using traditional condensed phase methods, but can be gently transferred intact into the gas-phase and isolated using electrospray ionization mass spectrometry. This collaboration includes F Zhang (UNSW), RAJ O’Hair (U Melbourne), C Hansen, A Trevitt, SJ Blanksby (U Wollongong), and CJ McKenzie (U Southern Denmark). The reactivity, lifetimes, and reaction products of metallic intermediates can be profoundly influenced by their confinement within micro-environments. Here, a technique for examining reactive intermediates in mass-selected and partially hydrated nanometer-sized cluster ions in vacuo by measuring the energy of reducing these clusters in ion-electron recombination experiments is described (developed with ER Williams and co-workers at UC Berkeley; [1-3,6-10]). Using this “nanocalorimetry” approach, it was discovered that partially hydrated electrides of divalent and trivalent metal ions, i.e., z+ – z+ – (z–1)+ solvent-separated metal ion (M ) and electron (e ) pairs, [M ,e ,(H2O)n] , can be formed. From these experiments, the effects of cluster size, metal ion identity, and oxidation state on the reactivity and stability of hydrated electrides can be obtained. The results from these experiments correlate beautifully with traditional electrochemical and photochemical experiments done in solution and provide a bridge between gas-phase and solution studies. An advantage of these measurements is that counter-ions can either be eliminated or precisely controlled by mass selection, which makes it possible to more readily measure metal ion and solvation effects directly.

References 1. W. A. Donald, R. D. Leib, J. T. O’Brien, A. I. S. Holm, E. R. Williams, Proc. Nat. Acad. Sci., U. S. A.2008, 105, 18102. 2. W. A. Donald, M. Demireva, R. D. Leib, M. J. Aiken, E. R. Williams, J. Am. Chem. Soc. 2010, 132, 4633. 3. W. A. Donald, C. J. McKenzie, R. A. J. O’Hair, Angew. Chem. Int. Ed. 2011, 50, 8379. 4. W. A. Donald, R. A. J. O’Hair, Dalton Trans. 2012, 41, 3185. 5. W. A. Donald, G. N. Khairallah, R. A. J. O'Hair, J. Am. Soc. Mass Spectrom. 2013, 24, 811. 6. W. A. Donald, R. D. Leib, J. T. O’Brien, M. F. Bush, E. R. Williams, J. Am. Chem. Soc. 2008, 130, 3371. 7. W. A. Donald, R. D. Leib, M. Demireva, J. T. O’Brien, J. S. Prell, E. R. Williams, E. R. J. Am. Chem. Soc. 2009, 131, 13328. 8. W. A. Donald, R. D. Leib, M. Demireva, B. Negru, D. M. Neumark, E. R. Williams, J. Am. Chem. Soc. 2010, 132, 6904. 9. W. A. Donald, R. D. Leib, M. Demireva, E. R. Williams, J. Am. Chem. Soc. 2011, 133, 18940. 10. W. A. Donald, E. R. Williams, in Electroanalytical Chemistry Series, Vol. 25; edited by C. G.Zoski, A. J. Bard, 2013, pp 1-32.

KN10A

Spin crossover and the scan rate dependence of thermal hysteresis

Sally Brooker,a* Matthew G. Cowan,a Juan Olguín,a Rafal Kulmaczewski,a Humphrey L.C. Feltham,a Reece G. Miller,a Guy N.L. Jameson,a Suresh Narayanaswamy,b Jeffery L. Tallonb

a Department of Chemistry and MacDiarmid Institute for Advanced Materials and Nanotechnology, University of Otago, PO Box 56, Dunedin 9054, New Zealand; b MacDiarmid Institute for Advanced Materials and Nanotechnology and Industrial Research Limited, PO Box 31310, Lower Hutt, New Zealand.

Email: [email protected]

Thermal hysteresis of spin crossover (SCO) is desirable if such compounds are to be used as futuristic nano-memory components. Wide loops have been seen in polymeric iron(II) materials1 and in monomeric iron(II) complexes which feature strong intermolecular packing interactions.2 However, hysteresis loops are far narrower in discrete polynuclear complexes of any metal ion3 and in general are far less common in cobalt(II) complexes.4

II 5 Here we present new studies on a triply switchable, hysteretic (Figure), mononuclear complex, [Co (dpzca)2], as well II as on a family of dinuclear iron(II) complexes, [Fe 2(PMRT)2](BF4)4, one of which has a remarkable, and record- equalling,6 hysteresis loop for a dimetallic complex.7 Detailed structural analysis, as well as variable temperature and pressure magnetic data, and the redox properties of the cobalt(II) complex, will be reported and discussed, along with our most recent advances in these ongoing studies, in particular our investigations into the effects of scan rate on thermal hysteresis loops.

References 1. J. Krober, E. Codjovi, O. Kahn, F. Groliere and C. Jay, J. Am. Chem. Soc., 1993, 115, 9810. 2. B. Weber, W. Bauer and J. Obel, Angew. Chem. Int. Ed., 2008, 47, 10098. 3. J. Olguín and S. Brooker, 'Spin crossover in discrete polynuclear complexes', in Spin-Crossover Materials: Properties and Applications, ISBN 9781119998679, ed. M. A. Halcrow, 2013. 4. S. Hayami, Y. Komatsu, T. Shimizu, H. Kamihata and Y. H. Lee, Coord. Chem. Rev., 2011, 255, 1981; H. A. Goodwin, Top. Curr. Chem., 2004, 234, 23; S. Brooker, P. G. Plieger, B. Moubaraki and K. S. Murray, Angew. Chem. Int. Ed., 1999, 38, 408. 5. M. G. Cowan, J. Olguín, S. Narayanaswamy, J. L. Tallon and S. Brooker, J. Am. Chem. Soc., 2012, 134, 2892. 6. B. Weber, E. S. Kaps, J. Obel, K. Achterhold and F. G. Parak, Inorg. Chem., 2008, 47, 10779. 7. J. A. Kitchen, N. G. White, G. N. L. Jameson, J. L. Tallon and S. Brooker, Inorg. Chem., 2011, 50, 4586; J. A. Kitchen, J. Olguín, R. Kulmaczewski, N. G. White, V. A. Milway, G. N. L. Jameson, J. L. Tallon and S. Brooker, Inorg. Chem. 2013, in press; R. Kulmaczewski, J. Olguín, J. A. Kitchen, H. L.C. Feltham, G. N. L. Jameson, J. L. Tallon and S. Brooker, JACS, in preparation.

KN11A

Inorganic-Organic Polyoxometalate Hybrids

Chris Ritchie, Peter Hall, Michele Vonci, Kristian Davies and Colette Boskovic

School of Chemistry, University of Melbourne, Melbourne, 3010, Australia.

Email: [email protected]

Methodologies for the preparation of inorganic-organic hybrid polyoxometalates have been developed with a number of applications in mind, where the complimentary properties of both the inorganic and organic components act synergistically to yield the desired physical properties.1-5 One of the most fascinating aspects of polyoxometalate chemistry related to the incorporation of organic components within the structural framework, is the ability of polyoxometalates to undergo structural rearrangements to accommodate the various synthons that come in contact with their oxygen rich surfaces.

Our recent work has been aimed at the development of new organically-derivatised polyoxometalates that display photo-chromic properties associated with intramolecular electron transfer. Achievement of the necessary structural criteria has been met by the incorporation of various amino acids as well as the site specific tuning of the inorganic composition.8 Indeed our 12- knowledge of the disassembly and reassembly tendencies of the lacunary and adaptive precursor [As2W19O67(H2O)] has enabled us to obtain crystalline derivatives with tuneable photochromic properties.6,9-11 Furthermore, single crystal X-ray studies have revealed the isolation of chiral polyoxometalates that crystallise in enantiomorphic space groups. Aggregation of the molecular polyoxometalates gives rise to micelle-like structures in which two unique types of void contain the hydrophobic groups of the organic components.6,7

III VI III 9- Fig. 1 Representations of [As 4W 47Y 5O143(C2H5NO2)9(H2O)11] (left) and VI V III 11- [As4W 45Mo 3Y 4O144(C6H13NO2)9(H2O)11] (right). The polyoxotungstate framework is displayed by yellow polyhedra. Y : Purple spheres; W : yellow spheres; Mo : green spheres; C : grey spheres; N : blue spheres; O : red spheres; aqua ligands : cyan spheres.

References 1. Z. Peng, Angew.Chem. Int. Ed., 2004, 43, 930. 2. V. Duffort, R. Thouvenot, C. Afonso, G. Izzet, A. Proust, Chem. Commun., 2009, 6062. 3. P. Mialane, G. Zhang, I. M. Mbomekalle, P. Yu, J.-D. Compain, A. Dolbecq, J. Marrot, F. Sécheresse, B. Keita, L. Nadjo, Chem. Eur. J., 2010, 16, 5572. 4. S.-T. Zheng, J. Zhang, G.-Y. Yang, Angew.Chem. Int. Ed., 2008, 47, 3909. 5. A. Proust, R. Thouvenot, P. Gouzerh, Chem. Commun., 2008, 1837. 6. C. Ritchie, E. G. Moore, M. Speldrich, P. Kögerler, C. Boskovic, Angew.Chem. Int. Ed., 2010, 49, 7702. 7. C. Ritchie, C. Streb, J. Thiel, S. G. Mitchell, H. N. Miras, D. Long, T. Boyd, R. D. Peacock, T. Mcglone, L. Cronin, Angew.Chem. Int. Ed., 2008, 47, 6881. 8. T. Yamase, Chem. Rev., 1998, 98, 307. 9. C. Ritchie, C. Boskovic, Cryst. Growth Des., 2010, 29, 488. 10. C. Ritchie, M. Speldrich, R. W. Gable, L. Sorace, P. Kögerler, C. Boskovic, Inorg. Chem. 2011, 50, 7004. 11. C. Ritchie, V. Baslon, E. G. Moore, C. Reber, C. Boskovic, Inorg. Chem. 2012, 51, 1142.

KN12A

Functional Supramolecular Metal Complexes: Just a “click” away

James D. Crowley1 1Department of Chemistry, University of Otago, PO Box 56, Dunedin, New Zealand.

E-mail: [email protected] . Access to functionalized metal complexes is of crucial importance in a range of different areas including catalysis, biology, metallosupramolecular chemistry and molecular machines. The mild and modular Cu(I)-catalyzed 1,3- cycloaddition of terminal alkynes with organic azides (the CuAAC “click” reaction) allows the ready formation of 1,4- disubstituted-1,2,3-triazole scaffolds and over the past ten years this reaction has become widely used in the synthesis of functional molecules.1a, 1b, 1c Initially, the 1,2,3-triazoles generated in the CuAAC reaction were just viewed as an “inert” connector units. However, more recently there has been an explosion of interest in the properties and coordination chemistry of these heterocycles. The 1,4-disubstituted-1,2,3-triazole ligands can display a range of coordination modes (both N and C bound) and have been incorporated into a diverse array of ligand architectures.2a, 2b We have previously exploited CuAAC methods to generate families of functionalized 1,4-disubstituted-1,2,3- triazole ligands3a, 3b and shown that these ligands can exploited in the development of catalysts,4 and optical materials.5a, 5b, 5c Here we shown that these “click” ligands can be used to generate a range of metallosupramolecular architectures6a, 6b, 6c, 6d, 6e including macrocycles, helicates (Figure 1) and cages. Additionally, the anti-fungal, anti-bacterial and anti- cancer activity of some these “click” complexes will be discussed.

4+ Figure 1. [Fe2L3] “click” helicates.

Acknowledgements: A University of Otago Research Grant and the Department of Chemistry, University of Otago provided financial support for this work.

References 1. a) Zheng, T.; Rouhanifard, S. H.; Jalloh, A. S.; Wu, P., Top. Heterocycl. Chem. 2012, 28, 163-183; b) Holub, J. M.; Kirshenbaum, K., Chem. Soc. Rev. 2010, 39, 1325-1337; c) Hein, J. E.; Fokin, V. V., Chem. Soc. Rev. 2010, 39, 1302-1315. 2. a) Crowley, J. D.; McMorran, D. A., Top. Heterocycl. Chem. 2012, 28, 31-83; b) Struthers, H.; Mindt, T. L.; Schibli, R., Dalton Trans. 2010, 39, 675-696. 3. a) Kilpin, K. J.; Gavey, E. L.; McAdam, C. J.; Anderson, C. B.; Lind, S. J.; Keep, C. C.; Gordon, K. C.; Crowley, J. D., Inorg. Chem. 2011, 50, 6334-6346; b) Crowley, J. D.; Bandeen, P. H.; Hanton, L. R., Polyhedron 2010, 29, 70-83. 4. Kilpin, K. J.; Paul, U. S. D.; Lee, A.-L.; Crowley, J. D., Chem. Commun. 2011, 47, 328-330. 5. a) Kim, T. Y.; Elliott, A. B. S.; Shaffer, K. J.; John McAdam, C.; Gordon, K. C.; Crowley, J. D., Polyhedron 2013, 52, 1391-1398; b) Anderson, C. B.; Elliott, A. B. S.; McAdam, C. J.; Gordon, K. C.; Crowley, J. D., Organometallics 2013, 32, 788-797; c) Anderson, C. B.; Elliott, A. B. S.; Lewis, J. E. M.; McAdam, C. J.; Gordon, K. C.; Crowley, J. D., Dalton Trans. 2012, 41, 14625-14632. 6. a) Lewis, J. E. M.; John McAdam, C.; Gardiner, M. G.; Crowley, J. D., Chem. Commun. 2013, 49, 3398-3400; b) Scott, S. O.; Gavey, E. L.; Lind, S. J.; Gordon, K. C.; Crowley, J. D., Dalton Trans. 2011, 40, 12117-12124; c) Gower, M. L.; Crowley, J. D., Dalton Trans. 2010, 39, 2371-2378; d) Crowley, J. D.; Gavey, E. L., Dalton Trans. 2010, 39, 4035-4037; e) Crowley, J. D.; Bandeen, P. H., Dalton Trans. 2010, 39, 612-623.

SL1A

When is a crystal not a crystal?

John McMurtrie, Zane Lao, Daniel Jager, Anna Worthy, Tri Nguyen, Tim Harding, Michael Pfrunder, Jocelyne Bouzaid, Llew Rintoul, Dennis Arnold and Jack Clegg

School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane 4001, Australia.

Email: [email protected]

A crystal, by definition, is a homogenous solid formed by a periodically repeating, three-dimensional pattern of atoms, ions, or molecules.

Properties displayed by crystalline solids, such as diffraction of light, spin crossover behavior, 2nd order nonlinear optics, piezoelectricity and ferro- ferri- and antiferromagnetism, are profoundly influenced by the spatial arrangement of the molecules from which they arise and specifically because those molecules are arranged in periodically repeating patterns. Our group has been exploring a range of different crystal formation phenomena. In the process we have uncovered “crystalline” systems that defy the classical definition of what it means to be a crystal. For example, we have prepared a variety of multi-component molecular and framework “crystals” containing metal complexes arranged in intracrystal solid-state concentration gradients. Another example is a suite of highly flexible “crystals” capable of remarkable and reversible elastic contortion. In this presentation I will discuss the design and synthesis of these new “crystalline” systems and the significance of their departure from the typical definition of crystalline materials.

Elastic flexibility in crystals of [Cu(acacBr)2] (left) and a crystal comprising [Cu(bipy)3](PF6)2 and [Ru(bipy)3](PF6)2 in which the metal complexes are arranged with an intracrystal concentration gradient (right).

SL1B Coordination Polymers Constructed from Redox-Active Ligands

Brendan F. Abrahams, Robert Elliott, Timothy A. Hudson, Christopher Kingsbury, Ryuichi Murase, Richard Robson and Keith F. White

School of Chemistry, University of Melbourne, 3010, Australia.

Email: [email protected] . 7,7,8,8-Tetracyanoquinodimethane (TCNQ) and the dianion of 2,5-dihydroxy-1,4-benzoquinone (H2dhbq) (figures 1 and 2 respectively) represent examples of quinonoid ligands that can act as "building blocks" in novel coordination networks. Both types of species may be reduced to radical or aromatic forms.

In the case of TCNQ (and a tetrafluoro analogue, TCNQF4) we have found that it is possible to stabilise the dianionic form by coordination to metal centres within coordination polymers. A wide range of novel coordination networks have 2- 2- been generated and structurally characterized in which the TCNQ (or TCNQF4 ) anion acts as a versatile 4-connecting planar unit. The dianionic form is found to act as a versatile rectangular building block within novel 1D, 2D and 3D architectures. In contrast to the neutral form of TCNQ, which commonly exhibits electron acceptor behaviour in charge- transfer complexes, the dianion is electron rich and has the potential to act as an electron donor within an infinite network. In this work, compounds will be described where the TCNQ dianion serves an electron donor in charge 2- transfer interactions. Figure 3 shows an Mn(II) TCNQF4 /pyridine network in which the electron acceptor, 1,4- benzoquinone, is incorporated into the channels.

The ligand dhbq2- (and related species) has been shown to acts as a 2-connecting unit within a wide range of coordination networks. As a ligand building block it offers the advantage of forming strong interactions with metal centres thus producing robust coordination polymers. Details of a novel synthetic approach for accessing new crystalline materials involving the reduced form of the ligand will be presented. In addition a number of interesting architectures will be described, some of which exhibit unexpected gas sorption properties.

Figure 1. TCNQ Figure 2. H2dhbq

Figure 3. The Mn(TCNQF4)(py)2 structure with 1,4-benzoquinone in the channels.

SL1C Redox-active Metal-Organic Frameworks and Porous Coordination Polymers

Deanna M. D’Alessandro

School of Chemistry, University of Sydney, Sydney 2006, Australia.

Email: [email protected] . The development of redox-active and conducting microporous materials are highly sought after goals: at a fundamental level these materials offer unprecedented insights into electron delocalisation in three-dimensional coordination space; at an applied level, they have potential for electrocatalytic conversion through to solar energy harvesting.1

This presentation will detail our latest results in the design and synthesis of Metal-Organic Frameworks (MOFs) and Porous Coordination Polymers (PCPs) that integrate molecular components for electron transfer including radical ligands, metal centres and mixed-valence clusters. The application of solid-state DC and AC electrochemical methods, as well as the development of a solid-state near-IR/Vis spectroelectrochemical technique2 will be described which provide powerful in situ probes for the electron transfer characteristics of redox-active materials. The exploitation of redox activity to reversibly switch the gas adsorption properties will also be discussed.3 The outcomes of this research on both a fundamental and applied level pave the way towards advanced multifunctional materials.

References 1. D. M. D’Alessandro, J. R. R. Kanga, J. S. Caddy, Aust. J. Chem. 2011, 64 (6), 718. 2. P. M. Usov, C. Fabian, D. M. D’Alessandro, Chem. Commun. 2012, 48, 3945. 3. C. F. Leong, T. B. Faust, P. Turner, P. M. Usov, C. J. Kepert, R. Babarao, A. W. Thornton, D. M. D’Alessandro, Dalton Trans. 2013, 42 (27), 9831.

SL1D

Adaptive Porous Materials for Gas Storage and Separation Applications

Kristina Konstas1, Melanie Kitchin1,2, Richelle Lyndon1,3, Sam Lau1, Ravichandar Babarao1, Cara 1 2 1 M. Doherty , Christian J. Doonan and Matthew R. Hill

1. CSIRO Materials Science and Engineering, Clayton South MDC VIC 3169, Australia. 2. School of Chemistry and Physics, University of Adelaide, SA 5005, Australia 3. Department of Chemical Engineering, Monash University, Clayton VIC 3800, Australia.

Email: [email protected] . Methane and hydrogen gas are fast becoming the future’s possible energy carrier solution for vehicle transportation. Although, there are current limitations to this strategy and one limitation is the storage of the gas. Significant efforts are being made to find a solution to the associated storage and operating problems. The use of adsorbent materials has become a possible solution, such as Metal Organic Frameworks (MOFs). MOFs are a hybrid material that have high surface areas and periodic porosity.[1] However, many MOFs have limited physiochemical stability or reduced gravimetric capacity. An alternative to overcome some of these drawbacks associated with MOFs, are a class of microporous organic polymers called Porous Aromatic Frameworks (PAFs) (Figure). Compared with MOFs, PAFs have superior stability due to covalent bonds holding the framework together compared to the chemically susceptible coordination bonds.[2-4] There are methods which are known to increase the interaction (enthalpy of adsorption) between the gas and the porous material, some of which include metallation, interpenetration, and optimisation of pore size and pore/framework infiltration with reactive species. The work presented here encompasses methods to improve the enthalpy of adsorption and gas storage capability of PAFs.[5]

References 1. H.K. Chae, D.Y. Siberio-Perez, J. Kim, Y. Go, M. Eddaoudi, A.J. Matzger, M. Figure: Schematic diagram of O’Keffe and O.M Yaghi, Nature, 2004, 6974, 523-527. PAF 2. D. Yuan, W. Lu, D. Zhao and H.-C. Zhou, Adv. Mater., 2001, 23, 3723-3725. 3. J. R. Holst and A.I. Cooper, Adv. Mater., 2010, 22, 5212-5216. 4. T. Ben, H. Ren, S. Ma, D. Cao, J. Lan, X. Jing, W. Wang, J. Xu, F. Deng, J.M. Simmons, S. Qiu and G. Zhu, Angew. Chem. Int. Ed., 2009, 48, 9457-9460. 5. K. Konstas, J. W. Taylor, A. W. Thornton, W. X. Lim, B. J. Cox, J. M. Hill, T. J. Bastow, A.J. Hill, D. F. Kennedy, C. M. Doherty, C. D. Wood, M.R. Hill, Angew. Chem. Int. Ed., 2012, 51(27), 6639.

SL2A The Synthesis of Metal-based Imaging Agents for the Diagnosis of Alzheimer's Disease

Paul S. Donnelly

School of Chemistry and Bio21 Institute, University of Melbourne, Melbourne, Australia, 3010.

Email: [email protected] . Alzheimer’s disease is the most common form of neurodegenerative dementia. The progression of the disease is associated with formation of protein deposits in the brain called Aβ plaques. The major constituent of Aβ plaques is aggregated Aβ(1-42) protein. Radioactive isotopes of copper and technetium are of interest in the development of new molecular diagnostic imaging agents that have the potential to assist in the diagnosis of Alzheimer's Disease and to monitor the progress of emerging therapies. The synthesis of copper and technetium complexes designed to specifically bind to Aβ plaques will be presented. The complexes have been prepared with radioactive 64Cu and 99mTc isotopes and are sufficiently stable in vivo for imaging applications. The new complexes bind selectively to Aβ plaques in human brain tissue collected from subjects with diagnosed Alzheimer's Disease and selected examples have the ability to cross the blood-brain barrier in animal models.

a) The chemical structure of a copper complex (CuIIL) that binds to Aβ plaques. b) (top): Serial section (5 μM) of frontal cortex brain tissue from a subject with Alzheimer's Disease where the Aβ plaques have been stained by immunohistochemistry; (bottom) contiguous serial section treated with CuIIL where the compound is detected by epi- fluorescent microscopy (λex = 359 , λem = 460 nm).

Acknowledgements The Australian Research Council for financial support.

SL2B

A varied approach to tracing the transformation of ruthenium anticancer drugs in cells

Hugh H. Harris,1 Sumy Antony1,2 and Leone Spiccia.2

1School of Chemistry and Physics, The University of Adelaide, SA 5005, Australia. 2School of Chemistry, Monash University, VIC 3800, Australia.

Email: [email protected]

A number of ruthenium compounds have entered clinical trials for cancer treatment in the last decade despite confusion surrounding their modes of action. This stems from a lack of direct evidence for their chemical transformation in biological fluids and their extra- and intra-cellular targeting that yields their respective therapeutic actions.

Recent work by the Lay group in particular has demonstrated that many of these drugs undergo very rapid transformation when exposed to the milieu of plasma proteins and Optical micrograph that the active species does not closely (top left) and XRF resemble the parent “prodrug”.[1] In elemental parallel, we have attempted to pin down the distribution maps of fate of some of the drugs in cells,[2] a single human especially the question of whether the cancer cell treated heterocyclic ligands remain attached and with the KP1019 that of how the metabolites are distributed in derivative shown treated cells. above.

I will describe our efforts to prepare analogues that are designed to probe each of these questions using a double-tagging X- ray fluorescence imaging approach [3] and by attempting to tag the heterocyclic ligands with optically fluorescent moieties to facilitate confocal microscopy.

References 1. Levina A, Aitken JB, Gwee YY, Lim ZJ, Liu M, Singharay AM, Wong PF and Lay PA. Chem. Eur. J. 2013, 19, 3609-3619. 2. Aitken JB, Antony S, Weekley CM, Lai B, Spiccia L and Harris HH. Metallomics 2012, 4, 1051-1056. 3. Antony S, Aitken JB, Vogt S, Lai B, Brown T, Spiccia L and Harris HH. J. Biol. Inorg. Chem. 2013, 18, 845-853.

SL2C Platinum Metallointercalators

Janice Aldrich-Wright, K. Benjamin Garbutcheon-Singh, Ben J. Pages, Dale Ang and Benjamin W. J. Harper

Nanoscale Organisation and Dynamics Group, School of Science and Health, University of Western Sydney, Penrith 2751, Australia.

Email: [email protected] . Cancer is a health challenge to Australians with 1 in 5 receiving a prognosis of death prior to age 85.1, 2 It is estimated that there are 12.7 million cases of cancer diagnosed worldwide each year and this is predicted to increase to 26 million by 2030.1 Platinum(II) anticancer drugs such as cisplatin and carboplatin, that covalently bind DNA, are effective against a range of tumours but disadvantages, such as toxicity, intrinsic and acquired resistance, and cross-resistance, compel researchers to investigate other metal complexes for their anticancer effects. Although many analogues of cisplatin have been synthesized in an effort to mitigate the disadvantages, so far very few new complexes have produced therapeutic drugs with improved efficacy.3 Cisplatin, carboplatin and oxaliplatin, inhibit DNA’s ability to replicate, by the formation of coordinate bonds with DNA. Different molecular strategies to inhibit cellular proliferation, such as intercalation, with the aim of decreasing toxicity and increasing cancer cytotoxicity are under 2+ investigation. We have developed metallointercalators of the type [Pt(IL)(AL)] , where IL is the intercalating ligand and AL is the ancillary ligand. The most cytotoxic complex of this group is [(5,6-dimethyl-1,10-phenanthroline)(1S,2S- diaminocyclohexane)platinum(II)]2+ (56MESS) which is more cytotoxic than cisplatin in almost all cell lines tested to date (Fig. 1).4 We report the synthesis and characterisation of metallointercalators, their cytotoxicity as well as our investigations into their mechanism of action.4-7

Fig. 1 The general structure of (a) 56MESS, (b) platinum complexes to be synthesised where AL is 1S,2S-diaminocyclopentane (SSDACP) or 1R,2R-diaminocyclopentane (RRDACP) and (c) platinum complexes to be synthesised where IL is dipyrido[3,2-d:2,3'-d]quinoxaline (dpq). (*) indicates a stereocentre, either S or R. Counter-ions have been omitted for clarity.

References 1. Cancer in Australia: an overview Australian Institute of Health and Welfare and Australasian Association of Cancer Registries, Canberra, 2012. 2. A. Jemal, R. Siegel, E. M. Ward, Y. Hao, J. Xu, T. Murray and M. J. Thun, CA: Cancer J. Clin., 2008, 58, 71. 3. Q. Lu, J. Med. Chem., 2007, 50, 2601. 4. A. M. Krause-Heuer, R. Grunert, S. Kuhne, M. Buczkowska, N. J. Wheate, D. D. Le Pevelen, L. R. Boag, D. M. Fisher, J. Kasparkova, J. Malina, P. J. Bednarski, V. Brabec and J. R. Aldrich-Wright, J. Med. Chem., 2009, 52, 5474. 5. S. Kemp, N. J. Wheate, D. P. Buck, M. Nikac, J. G. Collins and J. R. Aldrich-Wright, J. Inorg. Biochem., 2007, 101, 1049. 6. K. B. Garbutcheon-Singh, P. Leverett, S. Myers and J. R. Aldrich-Wright, Dalton Trans., 2013, 42, 918. 7. A. M. Krause-Heuer, M. Manohar, K. B. Garbutcheon-Singh, D. M. Fisher, J. Aldrich-Wright, Metallointercalators: Synthesis and Techniques to Probe Their Interactions with Biomolecules, 2011, 69.

SL2D

Bismuth – The ‘Green’ Metal? Delving into the Anti-Microbial and Cell Toxicity of Novel Bismuth(III) Compounds

Phil Andrews

School of Chemistry, Monash University, Clayton, Vic 3800, Australia

Email: [email protected] . The antimicrobial and chemotherapeutic activity of bismuth compounds is well established, and has been described and utilised for well over 200 years.1 Today bismuth(III) compounds are best known for their use in triple and quadruple therapies for the treatment and eradication of Helicobacter pylori; the bacterium which can cause stomach ulcers, gastritis, and gastric cancer.2 Their importance continues to grow as resistance to frontline antibiotics increases, and rescue regimens are required to combat serious bacterial infections, including H. pylori.3

To fully exploit the potential bismuth compounds have in protective and therapeutic applications, we need to understand much more about their coordination chemistry, their structure, solubility and stability, as well as their activity and behaviour in a biological environment. When compared to related metals, our knowledge in this arena is poorly developed.

Alongside its known antimicrobial activity,1 bismuth also appears somewhat unique amongst heavy metals in showing low systemic toxicity in humans. The biological chemistry surrounding this seeming contradiction needs to be explored and understood. Is bismuth as non-toxic as it is regularly claimed?

In recent years, we have developed new strategies for the synthesis of novel mononuclear homo- and heteroleptic bismuth(III) compounds and related polynuclear oxido clusters, incorporating a range of ligand families with a variety of functional groups. We have assessed the stability and solubility of these compounds alongside the structural and biological chemistry.4 This includes activity against a range of bacteria (incl. H. pylori and M. tuberculosis), the Leishmania parasite, as well as healthy mammalian cells. Some of these results and potential therapeutic applications will be discussed.

References 1. The Biological Chemistry of Arsenic Antimony and Bismuth, Ed. H. Sun; Pub. John Wiley and Sons, London, U.K. 2011. 2. G. Treiber, P. Malfertheiner and U. Klotz, Expert Opin. Pharmacother., 2007, 8, 329. 3. J. P. Gisbert, World J. Gastroenterol., 2008, 14, 5385. 4. For example; P. C. Andrews, R. L. Ferrero, C. M. Forsyth, P. C. Junk, J. G. Maclellan, R. M. Peiris, Organometallics, 2011, 30, 6283; P. C. Andrews, R. Frank, P. C. Junk, L. Kedzierski, I. Kumar, J. G.MacLellan, J. Inorg. Biochem., 2011, 105, 454. P. C. Andrews, P. C. Junk, L. Kedzierski, R. M. Peiris, Aust. J. Chem. 2013, DOI 10.1071/CH13374

SL3A Flexible quasi-solid-state dye-sensitised solar cells on plastic substrates using mesoporous TiO2 beads Yasmina Dkhissi,1 Rachel A. Caruso1 and Yi-Bing Cheng2

1School of Chemistry,The University of Melbourne, VIC 3010, Australia. 2Department of Materials Engineering, Monash University,VIC 3800, Australia.

Email: [email protected]

Given the rising global energy demand and the depletion of fossil fuels to come, the abundance of solar energy places solar power as a promising and renewable alternative for generating electricity. Dye-sensitised solar cells (DSCs) have attracted great attention since reported in Nature by Grätzel and O’Regan in 1991.1 In particular, interest has recently grown around flexible solar cells for their potential low cost roll-to-roll production process and their wide range of applications. However, flexible DSCs do not perform as well as their glass substrate equivalents, mostly due to the difficulty of making good quality TiO2 films on plastic substrates. Standard devices using liquid electrolytes have shown relatively high solar to electric power conversion efficiencies but are confronted by long-term stability issues. Solid state DSCs employ solid state hole transport materials to replace liquid electrolytes but require the use of a compact blocking layer, which is difficult to prepare on conductive plastic substrates. Consequently, constructing stable highly efficient flexible solar cells presents a major challenge. This presentation will focus on flexible quasi-solid state DSCs (QS-DSCs), an intermediate option thought to combine advantages of both systems so as to overcome the aforementioned issues. Submicrometre sized mesoporous TiO2 beads, developed in house, have demonstrated outstanding properties in flexible film applications.2,3 Therefore, such beads were used as the electrode in this study. The influence of the polymer gel electrolyte composition on the corresponding device performance has been investigated. The composition of the gel electrolyte was optimised to provide an effective pathway for the redox species to move in the electrolyte and a record power conversion efficiency of 6.4% for flexible QS-DSCs has been obtained (Figure 1). Flexible working electrodes prepared with bead and P25 TiO2 nanoparticle films were compared; devices fabricated with bead films achieving better photovoltaic performance. While diffusion issues were more prominent in P25 films, charge transport properties in P25 and bead films were comparable at similar film thickness. At optimised film thickness, the light harvesting of bead films increased at the expense of charge transfer capability.

Figure 1: A flexible quasi-solid-state dye-sensitised solar cell composed of a poly(vinylidenefluoride-co-hexafluoropropylene)/TiO2 based composite gel electrolyte and submicrometre mesoporous TiO2 beads on a plastic substrate gives a conversion efficiency of 6.4%.

References 1. O’Regan, B., Grätzel, M., Nature. 1991, 353, 723-729. 2. Chen, D., et al., Journal of the American Chemical Society. 2010, 132, 4438-4444. 3. Huang, F., et al., Applied Physics Letters. 2012, 100, 123102.

SL3B Birnessites as Bio-Inspired Water Oxidation Catalysts for Alternative Energy Production

Mathias Wiechen, Philipp Kurz and Leone Spiccia

a School of Chemistry, Monash University, VIC 3800, Australia. b Institute for Bioinorganic Chemistry, University of Freiburg, 79104 Freiburg, Germany.

Email: [email protected]

Solar energy has tremendous potential as an environmentally benign and sustainable energy source, but only a small fraction of the energy reaching earth is currently used in photovoltaics and solar thermal heating. To take full advantage of the enormous potential of the sun, solutions for both the capture of solar energy and its conversion into readily utilisable and storable forms are urgently required. Water splitting for H2 production, with O2 as a by-product, is an intensely discussed and investigated approach. One of the major stumbling blocks to achieving light driven water splitting has been a lack of robust catalysts based on non-toxic and abundant elements which promote water oxidation catalysts (a key component of any water splitting technology). Inspired by the natural water oxidation catalyst, the Mn4O5Ca-cluster of the Oxygen-Evolving-Complex (OEC) of photosystem II (PSII)1, we synthesized various manganese oxides containing intercalated Ca2+, Sr2+ or Mg2+ ions or K+ only.2 These layered manganese oxides are members of the birnessite family of minerals and closely resemble a number of structural aspects of the OEC (Figure, left and centre panel).2,3

Figure: The Mn4O5Ca-cluster of the OEC of PSII (left) is nature’s blueprint for water oxidation catalysts based on abundant and non-toxic elements. Manganese oxides of the birnessite family (centre) contain structural features of the OEC and show promising catalytic activity that can be increased by altering the composition of these materials (right).

In model experiments on water oxidation catalysis using the sacrificial oxidant CeIV, all studied birnessites showed promising catalytic activity (Figure, right panel).2 To our surprise, the trend in reactivity, Ca>Sr>Mg, was exactly the same as that established in experiments examining the effect exchanging the Ca2+ for other alkaline earth ion on the OEC catalytic activity.4 Based on our findings, we postulate a correlation between catalytic activity for water oxidation and structural motifs found in layered manganese oxides.2,3,5 Moreover, these materials are simple, but outstanding model systems for the OEC. In addition, birnessites are attractive water oxidation catalysts for use in light driven water splitting devices for H2 production. Further research will focus on the preparation of Ca-birnessite based electrocatalysts and the integration of these materials into photo-electrochemical cells for sunlight water splitting. First promising results for the preparation of such electrodes for water oxidation have already been achieved by screen-printing of manganese oxide particles.6 References 1. Y. Umena, K. Kawakami, J.-R. Shen, N. Kamiya, Nature 2011, 473, 55. 2. M. Wiechen, I. Zaharieva, H. Dau, P. Kurz, Chem. Sci. 2012, 3, 2330. 3. I. Zaharieva, M. M. Najafpour, M. Wiechen, M. Haumann, P. Kurz, H. Dau, Energy Environ. Sci. 2011, 4, 2400. 4. D. F. Ghanotakis, G. T. Babcock and C. F. Yocum, FEBS Lett. 1984, 167, 127. 5. M. Wiechen, H.-M. Berends, P. Kurz, Dalton Trans. 2012, 41, 21. 6. M. Fekete, R. K. Hocking, S. L. Y. Chang, C. Italiano, A. F. Patti, F. Arenae and L. Spiccia, Energy Environ. Sci. 2013, 6, 2222.

SL3C

Molybdenum-Based Oxide Nanowire as Heterogeneous Photocatalyst for O2 Evolution Kenji Saito, Shotaro Kazama, Kazuki Matsubara, Tatsuto Yui, and Masayuki Yagi

Department of Materials Science and Technology, Faculty of Engineering, Niigata University, 8050 Ikarashi-2, Nishi-Ku, Niigata 950-2181, Japan.

Email: [email protected]

Semiconductor nanowire where semiconducting characteristics as a bulk is confined to the magnitude of around 100 nm in two dimensions has merited special attention in terms of photocatalytic application. Thus far, there have been a number of reports of high-performance photo-electrocatalysts based on the nanowires that were synthesized by a gas- and liquid-phase reaction.1 In contrast, external-bias-free heterogeneous photocatalysis facilitates practical system construction compared to the photo-electrocatalysis, and thereby the development of high-performance heterogeneous nanowire photocatalysts has attracted increasing attention.2 We report herein a quite simple strategy that allows for the first ever synthesis of monoclinic Ag2Mo2O7 nanowire (m-Ag2Mo2O7-NW) with a unique stacked structure consisting of asymmetrical edge- and corner-shared MoO6 chains. The growth mechanism and photocatalytic activity for O2 evolution reaction are discussed as well. m-Ag2Mo2O7-NW was prepared by refluxing an aqueous AgNO3 suspension containing commercially available MoO3 particle for 5 h. The corresponding bulky counterpart was obtained by replacing the starting material of 6+ MoO3 to (NH4)6Mo7O24•4H2O, commonly used as Mo source for preparation of Mo-based oxide in the liquid phase reaction. The powders obtained were characterized using XRD, DRS, FE-SEM, TEM, XPS, and BET. Photocatalytic O2 evolution reactions were carried out using a gas-closed circulation system equipped with on-line gas chromatograph. XRD patterns of powder obtained were assigned to monoclinic Ag2Mo2O7 with unit cell parameters; a = 6.1138(5) Å, b = 13.1641(12) Å, c = 7.8730(4) Å.3 FE-SEM showed the product consisting of ca. 200 nm diameter nanowires, being sharp contrast to those of MoO3 particles. The structural and compositional information regarding m- Ag2Mo2O7-NW was taken in further detail using HR-TEM. Lattice fringes were clearly observed, and the width of 1.31 nm ± 0.03 nm agreed well with the d spacing of (010) of monoclinic Ag2Mo2O7 (d010 = 1.31 nm). An inverse FFT image taken from Fourier components indicated that the nanowire possessed exceptional highly crystalline surface, and single- crystalline nature of the nanowire was established by nano electron diffraction as well. The diffraction further indicated that [–201] perpendicular to [101] corresponded growth direction of m-Ag2Mo2O7-NW. Extensive control experiments revealed that a very slow supply of Mo6+ to the solution medium by diffusion promotes particle growth through an oriented aggregation mechanism that requires end-to-end and/or side-by-side structural accord between the crystals, in contrast to the case of a typical solution-phase method. m-Ag2Mo2O7-NW possessed sharp absorption edge at 416 nm. By examining photocatalytic experiments, the complete structural transformation from bulk to nanowire triggered + activity for the O2 evolution reaction in the presence of Ag as an electron acceptor under visible light irradiation (λ > 400 nm), presumably due to efficient electron-hole separation. This is the first example where the photocatalytic O2 4 evolution reaction proceeds on Ag2Mo2O7, regardless of the crystal system and particle size. This facile approach opens the door to engineer Ag-Mo-O materials working as heterogeneous photocatalyst with visible light response.

Figure 1. FE-SEM image of m-Ag2Mo2O7-NW. References 1. C. Liu, J. Tang, H. M. Chen, B. Liu, P. Yang, Nano Lett. 2013, 13, 2989. 2. K. Saito, A. Kudo, Inorg. Chem. 2010, 49, 2017. 3. G. Hong-Xu, L. Shi-Xiong, Chinese J. Struct. Chem. 2005, 24, 1452. 4. K. Saito, S. Kazama, K. Matsubara, T. Yui, M. Yagi, Inorg. Chem. 2013, 52, 8297.

SL3D Stable High Efficiency Dye-sensitized Solar Cells Based on a Cobalt Polymer Gel Electrolyte

Wanchun Xiang, Wenchao Huang, Udo Bach and Leone Spiccia

School of Chemistry, Monash University, Victoria 3800, Australia.

Email: [email protected]

2+/3+ Dye-sensitized solar cells (DSCs) with the efficiencies of up to 12.3% have been obtained employing [Co(bpy)3] (bpy = 2,2’-bipyridine) redox mediators.1 However, the widely used organic solvents, such as acetonitrile and 3- methoxypropionitrile (MPN), have the potential drawbacks of volatility and fluidity, which could result in evaporation and leakage during long-term usage. DSCs based on gel electrolyte can compete with liquid DSCs in terms of energy conversion efficiencies, and importantly, they have been reported to exhibit better long-term stability. In comparison to iodine/triiodide, one-electron cobalt(II)/(III) redox couples possess the advantage of non-corrosiveness and negligible visible absorption.2 Nevertheless, in the case of cobalt electrolytes, stability testing was reported for only 200 h illumination.1 Although gelation offers the advantage of minimizing electrolyte leakage while maintaining good contact between the dyed porous TiO2 film and redox mediator in the electrolyte, there is only one previous publication reporting the application of a cobalt gel electrolyte.3 By using nanoparticles to ‘solidify’ the liquid cobalt electrolyte, DSCs with 2.6% efficiency at 1 sun and 4.0% at 0.1 sun were obtained.

In our study, cobalt gel electrolytes with 4-10 wt% of PVDF-HFP in acetonitrile were incorporated into DSCs to examine the influence of the polymer content on DSC performance. For devices made with 4% polymer in the electrolyte, efficiencies of 8.7% were measured, the highest efficiency achieved so far for quasi-solid state DSCs based on a cobalt redox mediator. The photovoltaic performance for the polymer-free and polymer containing electrolytes at low illumination levels was unaffected by the addition of up to 10wt% of polymer, yielding a constant power 3+ conversion efficiency of 10%. The measurement of apparent diffusion coefficient of [Co(bpy)3] and photocurrent transients suggested that PVDF-HFP retards the charge carrier transport in the electrolyte and limits the photocurrent generation at 1 sun as the amount of the polymer is increased. Under 1 sun continuous illumination by white light LEDs, the gel devices were found to retain 90% of their initial efficiency after illumination for nearly 700 h, confirming the outstanding stability of the cobalt gel electrolyte based devices. On the contrary, the liquid polymer-free electrolyte based devices maintained 90% of the initial efficiency for less than 200 h and the efficiency dropped to 25% of its original value after 500 h. In addition, due to the successful introduction of aqueous electrolyte into DSCs2, we also developed aqueous gel electrolyte and promising device efficiencies as high as 4.1% under 1 sun were achieved.

References 1. A. Yella, H. W. Lee, H. N. Tsao, C. Yi, A. K. Chandiran, M. K. Nazeeruddin, E. W. G. Diau, C. Y. Yeh, S. M. Zakeeruddin and M. Grätzel, Science, 2011, 334, 629. 2. W. C. Xiang, F. Z. Huang, Y. B. Cheng, U. Bach and L. Spiccia, Energy Environ. Sci., 2013, 6, 121. 3. T. Stergiopoulos, M. Bidikoudi, V. Likodimos and P. Falaras, J. Mater. Chem., 2012, 22, 24430.

SL1F Storage, Separation and Triggered Release from Ultraporous Materials

Richelle Lyndon1,3, Melanie Kitchin1,5, Kristina Konstas1, Sam Lau1, Ravichandar Babarao1, Anastasios Polyzos1, Christian J. Doonan5, Bradley P. Ladewig3, David R. Turner2, Mainak Majumder4 and Matthew R. Hill1,5

1. CSIRO Materials Science and Engineering, Clayton South MDC VIC 3169, Australia. 2. School of Chemistry, Monash University, Clayton VIC 3800, Australia. 3. Department of Chemical Engineering, Monash University, Clayton VIC 3800, Australia. 4. Department of Mechanical Engineering, Monash University, Clayton VIC 3800, Australia. 5. School of Chemistry and Physics, University of Adelaide, SA 5005, Australia

Email: [email protected]

One of the challenges presently hampering the widespread deployment of post-combustion CO2 capture technology is the significant parasitic energy load associated with implementation of the most mature technologies currently available. In particular, the elevated temperatures required to decarboxylate amine solutions contributes to the parasitic energy load being as high as 30% of the power station’s production capacity. The Hill group at CSIRO have recently focussed on CO2 capture and separations using MOFs and closely related materials with a view to addressing this parasitic energy load. In this seminar some of the recent results in this area will be highlighted. These include the 1,5 2 development of materials with exceptionally high capacity, selectivity, the ability to release CO2 under the trigger of concentrated light instead of heat from the power station,3 and remarkable age-defiant mixed-matrix separation 4 membranes, which harbour the potential to separate CO2 in a low-energy, continuous fashion. Based on the fundamental findings of this CO2 related research, Matthew’s team have explored the triggered release of other molecules from within porous matrices. The results of this work in the agricultural field will be presented.

The presentation will summarise recent CSIRO work in developing porous materials for separation, storage and triggered release.

References 1. K. Konstas, J. W. Taylor, A. W. Thornton, W. X. Lim, B. J. Cox, J. M. Hill, T. J. Bastow, A.J. Hill, D. F. Kennedy, C. M. Doherty, C. D. Wood, M.R. Hill, Angew. Chem. Int. Ed., 2012, 51(27), 6639. 2. Majumder, M.; Sheath, P.; Mardel, J. I.; Harvey, T. G.; Thornton, A. W.; Gonzago, A.; Kennedy, D. F.; Madsen, I.; Taylor, J. W.; Turner, D. R.; Hill, M. R., Chem. Mater. 2012, 24, 24, 4647-4652, Editor's Choice, Science, January 2013, most read Chem Mater paper January 2013. 3. R. Lyndon, K. Konstas, B. P. Ladewig, P .Southon, C.J. Kepert, M.R. Hill, VIP paper, Angew. Chem. Int. Ed., 2013, 52 (13), 3695-3698, Lyndon, R.; Konstas, K.; Ladewig, B. P.; Hill, M. R. GAS SEPARATION PROCESSES TW8699/AU/PROV, 26-7-2012. 4. Nguyen, P. T.; Gin, D.; Noble, R. D.; Hill, M. R. Novel Membranes with Long-Term Gas Permeability Stability, and Methods of Preparing and Using Same. 61/729,758, 26-11-2012, 2012. Hill, M. R.; Nguyen, P. T.; Konstas, K.; Lau, C. H.; Gin, D.; Noble, R. D. Polymer Compositions. TW/8724/AU/PROV, 29-11-2012, 2012. 5. Lau, C. H.; Babarao, R.; Hill, M. R., "Post-synthetic exchange of metal ions in MOFs – a route to doubling CO2 uptake in UiO-66" Chem. Commun. 2013, 49(35) 3634, with cover art.

SL1G Open metal-ligand networks for gas storage

Keith White, Brendan Abrahams, David Dharma and Richard Robson

School of Chemistry, University of Melbourne, 3010, Australia.

Email: [email protected]

Coordination networks constructed with simple ligands bridging metal centres have yielded robust and porous materials which have been shown to be capable of hosting a variety of guest molecules.1 As such coordination networks have widely been considered as potentially useful materials for the storage of gaseous fuels2 and toxic polluting gases, in 3 particular anthropogenic CO2.

With the view to developing novel materials for the convenient storage of gases such as CO2, H2 and CH4 our group has focused on the design and synthesis of open coordination networks. Reported here is a recently established family of compounds that consist of metal cations (Li+, Co2+, Zn2+) linked with (in the case of Li+) the anion of (1), or (for Co2+ and Zn2+) the di-anion of (2) in 1:1 proportions to give frameworks with large square channels (3). From a topological perspective the metal-ligand frameworks possess the same connectivity as platinum sulfide. The materials obtained when combining Co2+ and Zn2+ with (2) exhibit high thermal stability and outstanding gas uptake capacities and isosteric heats of sorption. Extending the synthetic procedure to incorporate a range of structurally related di-anions in place of (2) provides a series of analogous structures that possess channels with larger cross-sectional dimensions and different chemical functionalities. At atmospheric pressures, these materials show a capacity to sorb greater volumes of gas than well-known MOFs.

(1) (2) (3)

References 1. T. Yoshitomi, H. Matsuzaka, S. Kitagawa, K. Seki, Angew. Chem. Int. Ed. 1997, 36, 1725-1727, M. Rosseinsky, Microporous Mesoporous Mater., 2004, 73, 15 2. T. A. Makal, J.-R. Li, W. Lu, H.-C. Zhou, Chemical Society Reviews 2012, 41, 7761-7779, Y. Sun, L. Wang, W. A, H. Yu, J. Ji, L. H, J. Shan, R. Tong, J. Inorg. Organomet. Polym. 2013, 23, 270 3. K. Sumida, David. Rogow, J. Mason, T. McDonald, E. Block, Z. Herm, T-H. Bae, J. Long, Chem. Rev. 2012, 112, 724

SL1H Coordination Polymers Containing Cyclic Amines; Crystal Engineering, Gas Sorption and Chromatographic Applications

Chris S. Hawes,1 Yada Nolvachai,2 Chadin Kulsing,2 Philip J. Marriott,2 Stuart R. Batten1 and David R. Turner1

1School of Chemistry, Monash University, Clayton, VIC 3800, Australia. 2Australian Centre for Research on Separation Science, School of Chemistry, Monash University, Wellington Road, Clayton, VIC 3800, Australia

Email: [email protected] . . Porous coordination polymers, sometimes referred to as Metal-Organic Frameworks (MOFs), have attracted considerable attention in the chemical literature in the past 20 years, largely due to their potential applications for gas storage and separation.1 More recently, the importance of selective carbon dioxide sorption has brought renewed interest into the synthesis of functionalized coordination polymers, particularly those containing functionalities capable of selective uptake and release of carbon dioxide, either directly from the atmosphere or enriched environments such as industrial flue gas streams.2 We have prepared a range of amine-functionalised porous coordination polymers based on cyclic amines and azamacrocycles, to explore the possibilities of incorporating active amine sites or macrocycle-bound metal ions within framework materials. These materials display fascinating structural features associated with the use of highly flexible linkers, as well as excellent gas uptake properties, including high CO2 selectivity. Although most commonly associated with gas uptake applications, MOFs display great potential in a wide range of other applications, based on the presence of nano-scale pores and surface features, as well as the potential for surface customization through careful ligand design. One such application which is frequently overlooked is the potential for framework materials to act as stationary phases in chromatographic separation and extraction techniques.3 We have employed two polymorphic MOF materials based on an azamacrocycle linker, exhibiting near-identical surface properties but differing in pore size and volume, to demonstrate size-selective separation on a range of organic analytes in a simple and effective separation system.

References 1. S. R. Batten, S. M. Neville and D. R. Turner, Coordination Polymers; Design, Analysis and Application, RSC Publishing, Cambridge, 2009 2. K. Sumida, D. L. Rogow, J. A. Mason, T. M. McDonald, E. D. Bloch, Z. R. Herm, T. H. Bae and J. R. Long, Chem Rev. 2012, 112, 724-781 3. J. R. Li, J. Sculley and H. C. Zhou, Chem. Rev. 2012, 112, 869-932

SL2F Metal Binding to Blood Proteins, the Extracellular Matrix and Cell Surfaces: New Insights into the Medicinal Properties of Metal Complexes

Peter A Lay, Aviva Levina, Hannah O’Riley

School of Chemistry, The University of Sydney, NSW 2006, Australia.

Email: [email protected] . Most metal drugs that are used, or have the potential to be used, in medicine are prodrugs, which mean that they are transformed into active forms to bring about their biological activities. To date, most attention as been directed to the reactions of these prodrugs within the cellular environment, including reactions with intracellular targets, but less attention has been directed towards understanding their reactions with blood proteins, the extracellular matrix and cell surfaces, which are important, and sometimes the most important interactions that define their biological activities. We will discuss a range of published and unpublished techniques that include recent research in: multi-modal imaging;1 X- ray absorption spectroscopic speciation;2 and various in vitro biochemical3 and cell assays,4 which are throwing new light on these processes.

Particular emphasis will be placed on factors that affect the cytotoxic versus anti-metastatic properties of anti-cancer drugs,5 and the biochemical processes involved in the anti-diabetic activities of metal complexes of Cr, Mo, V and W.6

References 1. J. B. Aitken, E. A. Carter, H. Eastgate, M. J. Hackett, H. H. Harris, A. Levina, Y.-C. Lee, C.-I. Chen, B. Lai, S. Vogt, P. A. Lay, Radiat. Phys. Chem., 2010, 79, 176-184; E. A. Carter, B. S. Rayner, A. I. McLeod, L. E. Wu, C. P. Marshall, A. Levina, J. B. Aitken, P. K. Witting, B. Lai, Z. Cai, S. Vogt, Y.-C. Lee, C.-I. Chen, M. J. Tobin, H. H. Harris, P. A. Lay, Mol Biosyst. 2010, 6, 1316-1322 2. J. B. Aitken, A. Levina, P. A. Lay, Curr. Top Med. Chem., 2011, 11, 553-571; L. Finney, Y. Chishti, T. Khare, C. Giometti, A. Levina, P. A. Lay, S. Vogt, ACS Chem. Biol., 2010, 5, 577-587; A. Levina, J. B. Aitken, Y. Y. Gwee, Z. J. Lim, M. Liu, A. Mitra Singharay, P. F. Wong, P. A. Lay, P. A. Chem. Eur. J. 2013, 19, 3609-3619. 3. A. Levina, P. A. Lay, Inorg. Chem. Front. 2013, submitted. 4. M. Liu, Z. J. Lim, Y. Y. Gwee, A. Levina, P. A.; Lay, Angew. Chem., Int. Ed. Engl., 2010, 49, 1661-1664. 5. A. Levina, A. Mitra, P. A. Lay, Metallomics, 2009, 1, 458-470. 6. A. Levina, P. A.; Lay, Dalton Trans. 2011, 40, 11675-11686,

SL2G Ultrasmall Inorganic Nanoparticles for Bioimaging Zhen Li, and Shixue Dou

Institute of Superconducting & Electronic Materials, University of Wollongong, Wollongong, NSW 2500, Australia

Email: [email protected]

When the size of inorganic particles is reduced to nano scale or sub-nanometer scale, they exhibit novel properties in comparison with their bulk analogues. One example is magnetic iron oxide nanoparticles (MIONs), which show superparamagnetism when their size is below the critical size (e.g. 20 nm for Fe3O4 particles) where they turn from ferromagnetic into superparamagnetic.1, 2 These superparamagnetic MIONs have been extensively used as negative contrast agents for magnetic resonance imaging (MRI) due to their strong magnetization.3 Further decrease of their size into ultrasmall range (D < 5.0 nm) leads to more suppression in negative enhancement effect than positive enhancement effect in MRI, simultaneously resulting in bright and dark images under T1- and T2-weighted MRI conditions.4-6 Another example is metal nanoparticles which display strong fluorescence when their size is reduced to sub-nanometer.7-9 These fluorescent metal nanoclusters have shown great potential in cell labeling and imaging as alternatives to fluorescent QDs. Here I will introduce our work (Figure 1) on (i) preparation and application of magnetic iron oxide nanoparticles for MRI;1-6 (ii) synthesis of ultrasmall metallic nanoclusters for fluorescence labeling and Figure 1. Ultrasmall inorganic nanoparticles for imaging;7-9 and (iii) preparation of QDs and surface bioimaging. functionalization for cell imaging.10-12

References 1. Z. Li, Q. Sun and M. Y. Gao, Angew. Chem. Int. Ed., 2005, 44, 123-126. 2. Z. Li, H. Chen, H. B. Bao and M. Y. Gao, Chem. Mater., 2004, 16, 1391-1393. 3. Z. Li, L. Wei, M. Y. Gao and H. Lei, Adv. Mater., 2005, 17, 1001-1005. 4. Z. Li, P. W. Yi, Q. Sun, H. Lei, H. L. Zhao, Z. H. Zhu, S. C. Smith, M. B. Lan and G. Q. Lu, Adv. Funct. Mater., 2012, 22, 2387-2393. 5. Z. Li, S. X. Wang, Q. Sun, H. L. Zhao, H. Lei, M. B. Lan, Z. X. Chen, X. L. Wang, S. X. Dou and G. Q. Lu, Adv. Healthcare Mater., 2013, 2, 958. 6. Z. Li, B. Tan, M. Allix, A. I. Cooper and M. J. Rosseinsky, Small, 2008, 4, 231-239. 7. H. Zhang, X. Huang, L. Li, G. W. Zhang, I. Hussain, Z. Li and B. Tan, Chem. Comm., 2012, 48, 567-569. 8. L. Li, Z. Li, H. Zhang, S. C. Zhang, I. Majeed and B. Tan, Nanoscale, 2013, 5, 1986-1992. 9. X. Huang, Y. Luo, Z. Li, B. Li, H. Zhang, I. Majeed, P. Zou and B. Tan, J. Phys. Chem. C, 2011, 115, 16753- 16763. . 10. Y. Zhu, Z. Li, M. Chen, H. M. Cooper, G. Q. Lu and Z. P. Xu, Chem. Mater., 2012, 24, 421-423. 11. Y. Zhu, Z. Li, M. Chen, H. M. Cooper, G. Q. Lu and Z. P. Xu, J. Colloid Interface Sci., 2013, 390, 3-10. 12. Y. Zhu, Z. Li, M. Chen, H. M. Cooper and Z. P. Xu, J. Mater. Chem. B, 2013, 1, 2315-2323.

SL2H Cyclometalated Iridium(III) Complexes as Luminescent Probes for Targeted Cell Imaging

Timothy U. Connell,a Janine L. James,b Jonathan M. White,a Anthony R. White,b Paul S. Donnelly.a

a) School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, b) The University of Melbourne, 3010, Australia c) Department of Pathology, The University of Melbourne, 3010, Australia

Email: [email protected]

The complexity of biological systems leads to many challenges in probing the intricacies of their molecular nature. Labelling a biological molecule with small, innocuous yet detectable sensors is a powerful technique to gain further insight into biological function. Historically, probes have been almost exclusively organic dyes however this research aims to explore the potential of underutilised luminescent transition-metal complexes as biological probes. Phosphorescent Iridium(III) metal complexes are an attractive alternative as they have long-lived triplet emission, large Stokes’ shifts, high photostability and the ability to easily tune the excitation and emission properties.1 For bioconjugation it is also important to have a suitable functional group present, such as a carboxylic acid or maleimide.

Novel cyclometalated Iridium(III) complexes were synthesised and characterised by X-ray crystallography, NMR spectroscopy, mass spectrometry, UV-Vis and fluorescence spectroscopy. Cellular uptake and toxicity of the complexes in SH-SY5Y cells was investigated using epifluorescence microscopy and LDH and MTT toxicity assays respectively. Post-synthetic modification introduced functional groups suitable for conjugation and these complexes were subsequently conjugated to the protein transferrin, responsible for iron transport in humans. Uptake and function of modified transferrin was monitored by confocal microscopy.

+ Left: An ORTEP representation of the cation [Ir(ppy)2(pyta-Bn)] , ellipsoids at the 40% probability level and hydrogen atoms omitted for clarity. Right: Percentage cell ‘viability’ of SH-SY5Y cells incubated with different concentrations + of [Ir(ppy)2(pyta-Bn)] for 1 hour.

The authors would like to thank the Australian Research Council, National Health and Medical Research Council and an Australian Postgraduate Award for funding.

Reference 1. Lo, K. K.-W., Choi, A. W.-T., Law, W. H.-T., Dalton Trans., 2012, 41(20), 6021.

SL3F Dynamic Coordination of NCN Pincer Ligands to Rh(I) and Ir(I) and the Consequence for Catalysis

Michael J. Page, Giulia Mancano and Barbara A. Messerle

School of Chemistry, University of New South Wales, Sydney 2052, Australia.

Email: [email protected] . Multidentate ligand architectures that exhibit dynamic coordination chemistry are of significant interest for the development of novel catalyst structures. Transition metal catalysts that contain hemilabile donor groups may display a high reactivity, through the availability of exposed coordination sites, while maintaining the stability of a coordinatively saturated complex.

Towards the aim of exploiting such reactivity we prepared the NCN pincer ligands 1 and 2 containing a central NHC moiety flanked by two weaker pyrazole donor groups. The coordination of 1 and 2 to Rh(I) and Ir(I) led to a surprisingly diverse number of coordination modes (κ3, κ2, κ1) and the isolation of an unusual bimetallic structure (µ- κ2,κ1). These Rh and Ir complexes were investigated for a number of catalytic reactions involving the addition of NH, OH or SiH bonds to alkynes. The small variation between 1 and 2 resulted in a large difference to the reactivity of their complexes during catalysis.

N N N N N N

N M N N Rh I Ir I N N M N N ( ) & ( ) N n n κ3 κ2 N N N N N N N N N N N N N N N n= 1 (1), 2 (2) M M N M 2 1 κ1 µ−κ ,κ

SL3G An incomplete mechanism for copper(I)-activated atom transfer reactions

Tim Zerk and Paul Bernhardt

School of Chemistry & Molecular Biosciences, University of Queensland, Brisbane, 4072, Australia

Email: [email protected]

Atom transfer radical addition (ATRA) and polymerisation (ATRP) reactions are commonly catalyzed by copper(I) complexes which react, reversibly, with a dormant alkyl halide initiator (RX) releasing a reactive organic radical R˙. The copper catalyst bears a multidentate N-donor ligand (L) and the active catalyst is simply CuIL. The role of the catalyst in these reactions is to abstract a halogen atom from RX forming the corresponding higher oxidation state species CuIILX. However, in order to perform its catalytic function (in multiple turnovers) the halido ligand must be released from the copper ion en route to regenerating the active catalyst CuIL. Thus CuIILX must undergo an electron transfer step (forming CuILX) and then dissociation of the anion. For the first time we investigate the previously unconsidered the CuILX/CuIL equilibrium. In doing so, we provide the first comprehensive activation mechanism for these reactions. Our studies of this equilibrium reveal that it controls the kinetics of the entire copper activation cycle.

CuIILX

sol +

sol = MeCN, DMSO e NMe k M N II 2 O act Cu e- N X Me O Me2 EX OEt k Me t Me I so Cu LX Me OEt l EtO k-t Me Me MeN NMe O CuI 2 N X O Me Me 2 k eac d t k OEt Ia,X so + X Me l kId,Br n a or i titi t - MeN NMe X CuI 2 kact k KATRP = Ia,X N KCu I X = kdeact Me ( ) 2 kId,X I Cu L

Reference 1. Zerk, T. J.; Bernhardt, P. V., Dalton Transactions 2013, 42, 11683-11694.

SL3H On the “Whitesides Test” for Catalyst Speciation: A Cautionary Tale

Gregory A. Price, Alan K. Brisdon, Robin G. Pritchard and Peter Quayle

School of Chemistry, The University of Manchester, Oxford Road, Manchester, UK, M13 9PL.

Email: [email protected]

In order to maximize the efficiency of transition metal catalysed processes it is important to understand the speciation of the catalyst. Some time ago Whitesides1 suggested that mercury(0) could be used as a selective poison for reactions catalysed by nanoparticles of certain metals, thereby enabling the distinction between homogeneous and heterogeneous catalytic pathways. During our investigations into the use of cyclometallated gold(III) complexes in organic synthesis we noted that 1 was an efficient catalyst for the promotion of A3 (aldehyde-amine-alkyne) multi-component reactions. We observed that addition of mercury(0) to A3-reactions catalysed by complexes 1-3 halted conversion, indicating the catalyst had been poisoned in some way. There are a only a few scattered reports in the literature where the requisite blank reactions have been carried out in order to determine potential alternate, mercury-mediated, catalyst decomposition pathways,2 a realization which persuaded us to investigate the background reaction between cyclometallated Au(III) complexes and Hg(0). In the event, the two phase reaction between gold(III) complexes 1-3 in chloroform, with redistilled mercury at 20 °C resulted in a hitherto unknown redox transmetallation between Hg(0) and Au(III). The new transmetallation process rapidly afforded the corresponding mercury(II) complexes 4-6, in moderate yields. The Hg(II) complexes were characterized by 1H, 13C, 199Hg NMR spectroscopy, elemental analysis and in the case of 6 by a single crystal X-ray diffraction analysis. This investigation serves to highlight the potential pitfalls which may arise when employing empirical chemical tests in order to infer the chemical speciation. Clearly appropriate blank reactions should be carried out in conjunction with these tests in order to discount the possibility of hitherto unknown reaction pathways for catalyst deactivation.

NMe 2 NMe2 Hg(0), CHCl3

Au o X 20 C, 2 h X Cl Hg Cl Cl 1 X = H 4 X = H

2 X = CF3 5 X = CF3 3 X = CH 6 X = CH 3 3

References 1. Whitesides, G. M.; Hackett, M.; Brainard, R. L.; Lavalleye, J. P. M.; Sowinski, A. F.; Izumi, A. N.; Moore, S. S.; Brown, D. W.; Staudt, E. M. Organometallics 1985, 4, 1819–1830. 2. Gorunova, O. N.; Livantsov, M. V.; Grishin, Y. K.; Ilyin, M. M.; Kochetkov, K. a.; Churakov, A. V.; Kuz’mina, L. G.; Khrustalev, V. N.; Dunina, V. V. J. Organomet. Chem. 2013, 737, 59–63.

SL4A Face-Directed Self-assembly of a Heterometallic Cage

Feng Li,a Florian Reichela and Jack K Cleggb

aSchool of Science and Health, University of Western Sydney, Penrith NSW 2751, Australia. bSchool of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia.

Email: [email protected]

In the field of metallo-supramolecular chemistry, finite nano-scale heterometillic coordination cages with interesting structures and the large cavity have received very considerable attention over recent years.1,2 Although a number of coordination cages have been developed, the design and successful construction of these systems, particularly those with heteronuclear coordination motifs, which can typically form on the nanometre scale, still represent a significant synthetic challenge. There are three types of synthetic methods successfully explored in construction of discrete heteronuclear coordination architectures: 1) nature selectivity of metal-ion-directed assembly in fabricating discrete metallo-supramolecular architectures with different metal ions and ligands; 2) preorganizational synthetic method within one single molecule in constructing the discrete heterometallic architectures; 3) metalloligands functionalised as building blocks reacting with additional metal ions and sometimes extra ligands. In our recently studies,3 suitable metalloligands are designed and the correct additional metal ions are selected for favouring structure. By using such metalloligand, a rare discrete heterometallic Fe3+/Cu2+ nanocage 1 is prepared (Figure 1).

Figure 1. The X-ray single-crystal structure of heterometallic cube 1. a) Perspective view emphasizing one of the C4 symmetry axes; b) view down one of the C3 axes; The large yellow sphere indicates the large cavity. c) Space-filling model of the structure. Solvent molecules, counter ions and hydrogen atoms are omitted for clarity.

References 1. S. Wang, J.-L. Zuo, H.-C. Zhou, H. J. Choi, Y. Ke, J. R. Long and X.-Z. You, Angew. Chem. Int. Ed.,Chem. Rev. 2004, 43, 5940. 2. M. B. Duriska, S. M. Neville, J. Lu, S. S. Iremonger, J. F. Boas, C. J. Kepert and S. R. Batten, Angew. Chem. Int. Ed., 2009, 48, 8919. 3. F. Reichel, J. K. Clegg,.K. Gloe, K.. Gloe, J. J. Weigand, J. K. Reynolds, C.-G. Li, J. R. Aldrich-Wright, C.J. Kepert, L.F. Lindoy, H.-C. Yao and F. Li, In preparation.

SL4B ‘Heterogenising’ homogeneous catalysts: Towards MOFs containing azolium and N- heterocyclic carbene links

Christopher J. Sumby,1 Alexandre Burgun,1 Marcus L. Cole,2 Rachel S Crees,1 and Christian J. Doonan1

1. Centre for Advanced Nanomaterials, School of Chemistry & Physics, University of Adelaide, Adelaide, SA 5005, Australia. 2. School of Chemistry, University of New South Wales, Sydney, Australia.

Email: [email protected]

Metal-organic frameworks are crystalline materials that are synthesised from metal ions or metal-oxide clusters (nodes) and organic building blocks (links).[1] Such materials show, among other things, promise in the area of gas separation (e.g. CO2/N2, CO2/CH4)[2] and as a platform material for ‘heterogenising’ existing homogenous catalysts.[3] Anchoring catalytic entities in a MOF may confer additional stability to the catalyst, enable size- and shape-selective catalysis and allow for easy separation with reduced loss of catalyst.[3]

One approach to heterogenise homogenous catalysts relies on modifying or designing organic links that will enable metal ions to be incorporated during or after framework synthesis in a non-structural role. In this regard, we have been investigating the synthesis and properties of (i) MOFs incorporating biphenyl links with additional binding sites;[4] (ii) MOFs containing ligands possessing non-coordinated chelating heterocyclic binding sites,[5] and; (iii) MOFs containing azolium and N-heterocyclic carbene (NHC) links.[6]

The last five years has seen a significant number of examples of MOFs containing both azolium and NHC links reported.[6b] This presentation will highlight some of these, the design strategies involved, describe our contributions to the area[6] and present some on-going results whereby we are investigating catalysis in examples of our MOF materials.

Figure. (a) The synthesis of an NHC containing MOF and (b) hydroboration of CO2 using the MOF as a catalyst. References 1. H.-C. Zhou, J. R. Long, O. M. Yaghi, Chem. Rev., 2012, 112, 673. T. R. Cook, Y.-R. Zheng, P. J. Stang, Chem. Rev., 2013, 113, 734. 2. D. M. D'Alessandro, B. Smit, J. R. Long, Angew. Chem. Int. Ed., 2010, 49, 6058. b) K. Sumida, D. L. Rogow, J. A. Mason, T. M. McDonald, E. D. Bloch, Z. R. Herm, T.-H. Bae, J. R. Long, Chem. Rev. 2012, 112, 724. 3. J. Lee, O. K. Farha, J. Roberts, K. A. Scheidt, S. T. Nguyen, J. T. Hupp, Chem. Soc. Rev., 2009, 38, 1450. 4. D. Rankine, A. Avellaneda, M. R. Hill, C. J. Doonan, C. J. Sumby, Chem. Comm. 2012, 48, 10328. T. D. Keene, D. Rankine, J. D. Evans, P. D. Southon, C. J. Kepert, J. B. Aitken, C. J. Sumby, C. J. Doonan, Dalton., 2013, 42, 7871. D. Rankine, T. D. Keene, C. J. Sumby, C. J. Doonan, CrystEngComm., 2013, accepted 2/09/13. 5. W. M. Bloch, A. Burgun, C. Coghlan, C. J. Doonan, C. J. Sumby, unpublished data. 6. (a) R. S. Crees, M. L. Cole, L. R. Hanton and C. J. Sumby, Inorg. Chem. 2010, 49, 1712. (b) A. Burgun, C. J. Doonan, C. J. Sumby, Aust. J. Chem. 2013, 66, 409.

SL4C Probing the Impact of Polar Functional Groups in Metal-Organic Frameworks on Carbon Dioxide Binding Mechanism

Anita Dasa, Christopher Richardsonb and Deanna M. D’Alessandroa

a School of Chemistry, University of Sydney, 2006, Australia b Department of Chemistry, The University of Wollongong, 2522, Australia

Email: [email protected] . Metal-organic frameworks (MOFs) are a class of porous material possessing high crystallinity, which may be specifically targeted to carbon dioxide (CO2) capture and separation in order to meet global targets associated with the reduction of CO2 emissions from industrial sources. The selectivity of MOFs for CO2 uptake over other gases (e.g. N2) may be improved through the introduction of polar functional groups known to specifically interact with carbon dioxide, e.g. amines, which react with CO2 in an acid-base mechanism. The specific mechanisms of CO2 adsorption in such functionalised materials may be elucidated using a combination of gas sorption, gravimetric analysis using mixed gas streams and in situ infrared spectroscopy. We have previously employed such techniques to investigate the behaviour of CO2 adsorption in two frameworks which have been post-synthetically functionalised with the secondary amine piperazine (pip), namely H3[(Cu4Cl)3(BTTri)8(pip)12], where H3BTTri = 1,3,5-tris(1H-1,2,3-triazol-5-yl)benzene, and [Ni2(dobdc)(pip)0.5], where dobdc = 1,4-dioxido-2,5- benzenedicarboxylate.1,2 We are further expanding our repertoire of novel materials to include a more diverse range of functional groups; in particular, we are investigating the interaction of CO2 molecules with pendant groups such as sulfones (Figure 1), sulfonates, carboxylic acids, primary amines and secondary amines. We are currently exploring the use of neutron diffraction techniques to probe the temperature- and concentration-dependent behaviour of CO2 binding to identify intermediate binding species, fully explore the binding mode of CO2 and investigate structural effects in these functionalised adsorbate materials. Based upon this data, it will be possible to explore specific chemical factors contributing to selective CO2 capture in solid state materials, and in doing so contribute to the design of new materials or improve upon existing ones for CO2 uptake.

Figure 1. Schematic indicating the significantly improved heat of interaction with CO2 in a sulfone-containing metal-organic framework References 1. A. Das, P.D. Southon, M. Zhao, C.J. Kepert, A.T. Harris, D.M. D’Alessandro. Dalton Trans. 2012, 41, 11739. 2. A. Das, M. Choucair, P.D. Southon, J.A. Mason, M. Zhao, C.J. Kepert, A.T. Harris, D.M. D’Alessandro. Micro. Meso. Mater. 2013, 174, 74.

SL4D Engineering Entanglement in Chiral Frameworks

David R Turner, Stephanie A. Boer, Chis S. Hawes and Laura J. McCormick

School of Chemistry, Monash University, Clayton, VIC 3800, Australia.

Email: [email protected] . Discrete, mechanically interlocked species, such as catenanes and rotaxanes, are well-known in coordination chemistry. Such species are frequently designed using supramolecular principles, predominantly exploiting hydrogen-bonding and π···π interactions. Whilst the design and rational synthesis of discrete interlocked compounds is relatively well understood, achieving control over interlocked complexes in the solid-state, i.e. controlled interpenetration of coordination polymers, can be a more tasking challenge. Whilst there are many reports in the literature of polycatenated structures and polyrotaxanes, these are largely ex post facto descriptions of topology rather than deliberately engineered architectures.

Our recent work has explored naphthalene and perylene diimides that possess amino-acid derived terminal groups and their use in the formation of enantiomerically pure coordination frameworks. The large aromatic surfaces of these diimide ligands gives rise to significant π interactions in many of their coordination compounds. We have utilized these ligands towards two ends (i) control of interpenetration topologies and (ii) formation of materials for conducting enantiomeric separations.

Use of alanine and leucine naphthalenediimides yielded materials in which interpenetration could be controlled by the steric bulk of the amino acid. The cis geometry of the ligands allow for the formation of macrocycles that join into a one-dimensional chain (see figure). These chains form a 1D→2D polycatenated motif with alanine but not with the more sterically demanding leucine-derived ligand. A rare 1D→3D polyrotaxane can instead be synthesized when using bipyridine as a bridge between the metallomacrocyles.

We have also demonstrated that 2D→3D interpenetrated coordination networks can be formed that contain solvent- lined channels. These have been used in initial testing to show that racemic mixtures can be separated by passing a solution through a short, packed sample. These initial results bode well for the potential of these materials as stationary phases for chiral separations.

References 1. (a) L. Carlucci, G. Ciani and D. M. Proserpio, Coord. Chem. Rev., 2003, 246, 247. (b) J. Yang, J.-F. Ma and S. R. Batten, Chem. Commun., 2012, 48, 7899. 2. L.J. McCormick and D.R. Turner, Crystengcomm, 2013, DOI: 10.1039/c3ce41538d

SL5A Developing nitric oxide sensing silk

Trevor D. Rapson,a Holly Trueman,a Jeffrey S. Church,b Helen Dacres,a Tara Sutherlanda and Stephen C. Trowella

a Ecosystem Sciences, CSIRO, GPO Box 1700, Acton, ACT, 2601. b Materials Science and Engineering, CSIRO, PO Box 21, Geelong, VIC, 3216.

Email: [email protected]

Bio-synthetic silk can be cast into transparent films which are ideal for use in optically transduced biosensors.1 In this study we utilised a honey bee silk expressed in bacteria2 to fabricate a nitric oxide sensor. Nitric oxide binding is conferred by the incorporation of a haem protein into the silk film.

When myoglobin and haemoglobin are immobilised in silk films, both proteins can be readily reduced, re-oxidised and bind nitric oxide. The immobilised haem proteins show remarkable stability. They can be stored at room temperature in the dry films and reused for several months without loss of their gas binding ability.

The spectral shift of the Soret peak with nitric oxide binding (Figure 1) indicates a dissociation of the axial histidine ligand. This dissociation is fully reversible and appears to follow a mechanism similar to that seen in soluble guanylate cyclase (sGC), a nitric oxide binding protein involved in vascular dilation, whose cyclase activity is activated by the binding of nitric oxide and subsequent histidine dissociation.3

Using the films developed we are designing an optical biosensor to measure elevated nitric oxide levels in exhaled breath associated with inflammatory lung infections.4 The goal is to produce a portable nitric oxide sensor enabling the early detection of allergenic asthma.

0.12 Fe3+Mb

Fe2+Mb 0.10 Fe2+Mb - NO 0.08

0.06

0.04 Absorbance

0.02

350 400 450 500 550 600

Wavelength (nm)

Figure 1: Spectral changes with reduction and nitric oxide binding of myoglobin (FeMb) immobilised in silk films.

References 1. P. Domachuk, H. Perry, J. J. Amsden, D. L. Kaplan and F. G. Omenetto, Appl. Phys. Lett. 2009, 95, 253702. 2. J. S. Church, M. G. Huson and T. D. Sutherland, Biophys. J. 2013, 104, 48A. 3. E. R. Derbyshire and M. A. Marletta, Annu. Rev. Biochem. 2012, 81, 533. 4. R. Dweik, P. Boggs, S. Erzurum and C. Irvin, Am. J. Respir. Care Med. 2011, 184, 602.

SL5B Exploring the photochemistry of Re(I) N-heterocyclic carbene complexes in search of new agents for carbon monoxide therapy

Max Massi,1 Jamila G. Vaughan,1 Brodie L. Reid,1 Phillip J. Wright,1 Sara Muzzioli,2 David H. Brown,1 Stefano Stagni2

1. Department of Chemistry, Curtin University, Perth, Australia. 2. Department of Industrial Chemistry, University of Bologna, Bologna, Italy.

Email: [email protected] . The photophysical properties of tricarbonyl rhenium(I) complexes bound to chelating N-heterocyclic carbene (NHC) 1 ligands, fac-[Re(CO)3(NHC)X] (X = Cl, Br), have been recently reported. We have now extended our investigation from the photophysical to the photochemical properties of these complexes:2 in fact, we have discovered that upon excitation to their lowest metal-to-ligand charge transfer (MLCT) manifold, CO substitution occurs with formation of rhenium(I) dicarbonyl species. While an initial description of the process involved the strong σ-donation of the C atom of the NHC ligand, thus promoting the labilisation of the CO in trans from thermally accessible reactive excited states, as previously described for analogous complexes bound to phosphines and phosphites,3 this mechanism alone does not seem to explain the various products obtained during the present photochemical CO substitution. Our investigation points out that a key role in the process is the photochemical formation of a cationic solvato-complex fac- + [Re(CO)3(NHC)(Solv)] , which appears to be itself a photochemically active species. The photochemistry of fac- [Re(CO)3(NHC)X] is illustrated in this report using a combination of spectroscopic and structural techniques alongside systematic synthetic variations of the initial complexes to corroborate the proposed mechanisms. These complexes are also investigated in view of their potential application in carbon monoxide based therapies as photochemically activated CO-releasing agents (photoCORMs): in this respect, our effort in trying to manipulate the rate of CO photodissociation through external factors (e.g. pH-responsive electron transfer mechanisms) will also be discussed.

References 1. S. Muzzioli, S. Stagni, M. Massi et al. Dalton Trans. 2011, 40, 11960. 2. J. Vaughan, B. Reid, M. Massi et al. Dalton Trans. 2013, DOI: 10.1039/C3DT51614H, in press. 3. K. Koike, O. Ishitani et al. J. Am. Chem. Soc. 2012, 124, 11448.

SL5C Manganese Tricarbonyl and Tetracarbonyl Complexes with a Robust DAB ligand: Remarkable Photoreactivity and CO Releasing Properties

Veeranna Yempally, Abdul Malik Puthan Peedikakkal, Tan Geok Kheng , Samuel J. Kyran, Fan Wai Yip, Donald J. Darensbourg, and Ashfaq A. Bengali

Department of Chemistry, Texas A&M University at Qatar, Doha, Qatar. Department of Chemistry, National University of Singapore, Kent Ridge, Singapore. Department of Chemistry, Texas A&M University, College Station, Texas 77843.

Email: [email protected]. . The manganese tricarbonyl complex [Mn(CO)3Br(DAB)], 1, (DAB = {N, N'-bis(2,6-di-isopropylphenyl)-1,4- diazabuta-1,3-diene-1,4-diyl}) was synthesized from the reaction of Mn(CO)5Br with the DAB ligand. It was observed that CO ligands on compound 1 are photolabile, and under visible light irradiation all the three CO molecules were released from the dichloromethane solution of 1. The reaction of compound 1 with TlPF6 in dark afforded manganese (I) tetracarbonyl complex [Mn(CO)4(DAB)] [PF6], 2. The compound 2 is comparatively more stable than 1 in light, and also acts as photo-CORM on irradiation with the visible light. The photolytic ligand substitution of equatorial CO group on 2 with various solvent molecules was investigated using time resolved infrared spectroscopy. The reaction is found to proceed by a dissociative mechanism through a very unstable, short lived intermediate species [Mn(CO)3(DAB)(FPF5)], 3. The compound 3 further reacts with solvent molecule to yield respective solvent activated complex [Mn(CO)3(DAB)(S)] [PF6] ( S = CH3CN, CH2Cl2, and Tetrahydrofuran).

- - PF PF Ar 6 Ar 6 S CO OC N OC N + Solvent ∆ Mn Mn -CO OC N OC N CO CO Ar Ar 4 2 ( ) ( )

SL5D Redox Mediators Based on Co(II)/(III) Complexes of Polydentate Pyridyl Ligands

Muhammad Kalim Kashif, Michael Nippe, Jordan Axelson, Noel W. Duffy, Craig M. Forsyth, Christopher J. Chang, Jeffrey R. Long, Leone Spiccia, Udo Bach

Department of Materials Engineering, Monash University, Victoria 3800, Australia

Email: [email protected] . Dye-sensitized solar cell (DSC) is a promising, inexpensive technology that could help the world meet future energy requirements. DSCs are attractive alternatives to classical photovoltaics because they can potentially be produced at low cost via well-established commercial printing technologies. They also have the advantage of being able to operate in diffuse sunlight. However, industrial production of large-scale DSCs is still imminent. One aspect crucial for the industrial application of DSCs is a non-corrosive and robust electrolyte system. A major drawback - - associated with the hitherto ubiquitous I /I3 based electrolyte is its corrosive nature. In addition, much energy is wasted - - due to the fixed redox potential of I /I3 and the mismatch in potential between commonly used dyes and this redox couple. Ideally, the use of a tunable redox couple would provide the opportunity to adjust the redox potential corresponding to the highest occupied molecular orbital (HOMO) level of the dye. This will successively reduce the dye-regeneration driving forces and maximize achievable overall efficiency. Cobalt (II)/(III) redox mediators based electrolytes used as redox shuttles, have attracted a lot of attention after 2+/3+ the successful application of [Co(bpy)3] redox mediator. Most of the cobalt(II)/(III) complexes applied as redox mediators so far are bidentate or tridentate polypyridyl ligands. Our research into alternative redox mediators is focused on the synthesis of cobalt(II)/(III) complexes with polypyridyl ligands of higher denticity (pentadentate and hexadentate) and their application as redox mediators in DSCs. 1 2+/3+ In the case of pentadentate ligand with the general formula [Co(L1)(Y)] , the ligand, L1, and the weakly bound ligand, Y, coordinate the cobalt in a slightly distorted octahedral geometry. We show that alternative Lewis bases (B), which are important electrolyte components, can easily replace the monodentate ligand Y. Using an organic sensitizer we have attained efficiencies of 8.4% and 9.4% at simulated light intensity of 100% sun (1,000 Wm-2 AM1.5) a and at 10% sun, respectively, with an open circuit voltage (VOC) in excess of 1V at 100% sun . In case of a hexadentate2 polypyridyl ligand a new cobalt complex was synthesized using a judiciously engineered hexapyridyl ligand. The complex [Co(L')]2+/3+, where L' = a hexapyridyl ligand, is characterized using various techniques. The 2+/3+ redox mediator based on this complex resulted in higher DSC efficiencies than the [Co(bpy)3] couple. Most importantly, the lab scale devices made with this redox mediator exhibited much improved stability under full sun aging 2+/3+ experiments as compared to those based on [Co(bpy)3] , highlighting the potentially pivotal role played by the high denticity metal complex in the future development of DSC redox mediators.

Diagram illustrating the DSC components

and the hexadentate cobalt(II)/(III) complex (redox mediator)

References 1. Kashif, M.K.; Nippe, M.; Duffy, N. W.; Forsyth, C. M.; Chang, C. J.; Long, J. R.; Spiccia, L.; Bach, U. “Stable Dye-Sensitized Solar Cell Electrolytes Based on Cobalt (II)/(III) Complexes of a Hexadentate Pyridyl Ligand” Angew. Chem. Int. Ed., 2013, 52, 5527-5531 2. Kashif, M.K.; Axelson, J.C.; Duffy, N. W.; Forsyth, C. M.; Chang, C. J.; Long, J. R.; Spiccia, L.; Bach, U. “A New Direction in Dye-Sensitized Solar Cells Redox Mediator Development: In Situ Fine-Tuning of the Cobalt (II)/(III) Redox Potential through Lewis Base Interactions” Journal of the American Chemical Society, 2012, 134, 16646-16653.

SL6A Synthesis of Imidazoliumyl-substituted Phosphanes and their Reactivity

Florian D. Henne, Jan J. Weigand*

TU Dresden, Fakultät für Chemie und Lebensmittelchemie, 01062 Dresden, Germany.

Email: [email protected].

The intention of our research is to contribute to the field of synthetic chemistry by identifying and developing highly- reactive phosphorus reagents. We are particularly interested in Weiss-type compounds[1] containing C–based ligands + [2,3] (Chart, LC = imidazoliumyl). One interesting challenge in this area is the synthesis of cationic phosphorus compounds that carry halide substituents. We recently reported a convenient protocol for the synthesis of cations of the + + 2+ 2+ 3+ 3+ [2] type [LCPCl2] (1 ), [(LC)2PCl] (2 ) and [(LC)3P] (3 ), using an imidazolium-transfer reagent [LCSiMe3][OTf]. The chlorine atoms in these reactive cations can be substituted by cyano and azido groups. Ring formation is observed 2+ when cation 2 is reacted with S(SiMe3)2 depending on the reaction condition. A bridging chloride anion between two electrophilic phosphorus centers was observed for the first time in the molecular structure of the novel P−P bonded + + [4] cation [(LC)2P2Cl3] when cation 1 is reduced with elemental sodium. The extensive experimental work towards these compounds will be discussed in this contribution.

References 1. a) R. Weiss, S. Engel, Synthesis 1991, 1077; b) R. Weiss, S. Engel, Angew. Chem. Int. Ed. Engl. 1992, 31, 216. 2. K.-O. Feldmann, J. J. Weigand, Angew. Chem. Int. Ed. 2012, 51, 6566. 3. J. J. Weigand, K.-O. Feldmann, F. D. Henne, J. Am. Chem. Soc. 2010, 132, 16321. 4. F. D. Henne, E.-M. Schnöckelborg, K.-O. Feldmann, J. Grunenberg, R. Wolf, J. J. Weigand, Organometallics 2013, doi 10.1021/om4002268.

SL6B A Two-step Valence Tautomeric Transition in a Dinuclear Cobalt Complex Arising from Spiroconjugation of the Redox-active Ligand

Colette Boskovic, Kerwyn G. Alley, Brendan F. Abrahams, Keith S. Murray, Alan M. Bond, Giordano Poneti and Lorenzo Sorace

School of Chemistry, University of Melbourne, 3010, Australia; School of Chemistry, Monash University, Clayton 3800, Australia; Department of Chemistry, University of Florence, 50019 Sesto Fiorentino, Italy.

Email: [email protected] . Six members of a family of dinuclear cobalt complexes with a bridging bis(dioxolene) ligand derived from 3,3,3',3'- tetramethyl-1,1'-spirobis(indane-5,5',6,6'-tetrol) (spiroH4) and ancillary ligands based on tris(2-pyridylmethyl)amine have been synthesized and characterized.1,2 The bis(dioxolene) ligand is redox-active and accessible in the (spirocat-cat)4- , (spiroSQ-cat)3- and (spiroSQ-SQ)2- forms, (cat = catecholate, SQ = semiquinonate). Variation of the ancillary ligand by successive methylation of the 6-position of the pyridine rings influences the redox state of the complex, governing the distribution of electrons between the cobalt centers and dioxolene ligands. A structural, spectroscopic, electrochemical and magnetochemical study provides clear evidence for four different charge distributions accross the six complexes: CoIII-(spirocat-cat)-CoIII,CoII-(spiroSQ-SQ)-CoII, CoIII-(spiroSQ-cat)-CoIII and CoIII-(spiroSQ-SQ)-CoIII. One of the complexes exhibits temperature-dependence of the charge distribution, displaying a rare thermally-induced two-step valence tautomeric (VT) transition from the CoIII-(spirocat-cat)-CoIII form to CoII-(spiroSQ-cat)-CoIII and then to CoII-(spiroSQ-SQ)- CoII in both solid and solution states. This is the first time a two-step VT transition has been observed in solution. Partial photoinduction of the VT transition is also possible in the solid. Magnetic and spectroscopic studies reveal that spiroconjugation of the bis(dioxolene) ligand allows electronic interaction across the spiro bridge, suggesting that thermally activated vibronic coupling between the two cobalt-dioxolene moieties plays a key role in the observed two- step transition.

References 1. K. G. Alley, G. Poneti, J. B. Aitken, R. K. Hocking, B. Moubaraki, K. S. Murray, B. F. Abrahams, H. H. Harris, L. Sorace, C. Boskovic, Inorg. Chem. 2012, 51, 3944. 2. K. G. Alley, G. Poneti, P. S. D. Robinson, A. Nafady, B. Moubaraki, J. B. Aitken, S. C. Drew, C. Ritchie, B. F. Abrahams, R. K. Hocking, K. S. Murray, A. M. Bond, H. H. Harris, L. Sorace, C. Boskovic, J. Am. Chem. Soc. 2013, 135, 8304.

SL6C Photochemical Preparation of Actinide-Transition Metal Bonds: Synthesis, Characterization and Reactivity of a Series of Thorium and Uranium Heterobimetallics

Ashleigh L. Ward, Wayne W. Lukens and John Arnold

Department of Chemistry, University of California, Berkeley, Berkeley CA, 94709, USA.

Email: [email protected]

A series of actinide-transition metal heterobimetallics have been prepared featuring thorium, uranium and i cobalt. Complexes utilizing the binucleating ligand N(ο-(NHCH2P Pr2)C6H4)3, Th(IV) and U(IV) and a carbonyl - bridged [Co(CO)3] unit were irradiated with ultraviolet light, resulting in the first actinide-metal bonds to be accessed via photolysis. The synthesis and characterization of a rare U-Co bond and the first Th-Co bond, as well as their precursors, is presented. The series of thorium and uranium complexes was characterized by single-crystal X-ray diffraction, infrared and UV-Vis/NIR spectroscopy, 1H, 1H-1H COSY, variable-temperature and 31P NMR spectroscopy, variable-temperature magnetic susceptibility and elemental analysis. These actinide compounds demonstrate a novel way to achieve actinide-metal bonds and represent an exciting platform for the expansion of the study of actinide metal- metal bonding and reactivity.

References 1. Fox, A. R.; Bart, S. C.; Meyer, K.; Cummins, C. C. Nature 2008, 455, 341. 2. Liddle, S. T.; Mills, D. P. Dalton Trans. 2009, 29, 5592. 3. Ward, A. L., Lukens, W. W., Arnold, J. manuscript in preparation.

SL6D Multimetallic Catalysis for Efficient Heterocycle Synthesis: From Homogeneous to Supported Catalysts

Sandra Choy, Michael Page Mark Gatus, Andrey Tregubov and Barbara Messerle

School of Chemistry, University of New South Wales, High Street, Kensington, 2052, Australia

Email: [email protected] . Transition metal catalysts can be used to promote the highly efficient synthesis of heterocycles. We have shown that Rh(I) and Ir(I) complexes containing N’N donor ligands are effective catalysts for the hydroamination reaction, as well as tandem reactions such as dihydroalkoxylation. In particular, we have shown that bimetallic bispyrazolyl-methane complexes of Ir(I) and/or Rh(I) are significantly more efficient catalysts than their monometallic counterparts and that the two metal centres work cooperatively to promote both one and two step reactions.1 We have also made very significant improvements to the intermetallic cooperativity of the bimetallic systems using a novel series of Rh(I) complexes that are geometrically constrained such that the bimetallic complexes allow close approach of the two metal centres and enhanced bimetallic cooperativity (Figure 1).2 Figure 1

The covalent immobilisation of transition metal catalysts on solid supports offers the possibility of combining the significant advantages of homogeneous catalysis with the benefits of heterogeneous catalysts as well as the potential benefits of alignment of metal complexes for enhancing catalysis. We have also immobilized a series of Rh(I) complexes bearing N,N and N,P donor ligands on glassy carbon surfaces with robust C-C linkers The immobilized complexes achieved significantly higher turnover numbers than those of their homogeneous counterparts.

References 1. Ho. J. H. H, Choy. S. W. S, Macgregor. S. A, Messerle. B. A, Organometallics, 2011, 30, 5978. 2. Choy. S.W.S., Page. M. J., Bhadbhade M., Messerle. B.A., Organometallics, 2013, 32, 4726

SL4F Interactions Between Quadruplex DNA And Nickel Schiff Base Complexes

Stephen F. Ralph,1 K.J. Davis,1 J. L. Beck,1 C. Richardson,1 and A.C. Willis2

1School of Chemistry, University of Wollongong, NSW, 2522, Australia. 2Research School of Chemistry, The Australian National University, Canberra, ACT, 0200, Australia.

Email: [email protected]

Quadruplex DNA (qDNA) structures are attracting interest as a drug target owing to their presence in non-coding regions at the ends of chromosomes known as telomeres. The latter protect chromosomes during DNA replication, as significant strand shortening occurs with every cycle of cell division owing to an inherent issue associated with the mechanism of action of DNA polymerase. Normal cells enter apoptosis when its DNA strands shorten to the point that they can no longer function as the template for protein synthesis.1-2 In contrast, approximately 85% of tumour cells possess elevated levels of the enzyme telomerase, which is responsible for maintaining the length of telomeres, thereby contributing to tumour cell immortality.3 Drugs that can bind selectively to, and stabilise qDNA structures are believed to inhibit telomerase, and therefore have potential as novel anti-cancer agents. One group of compounds that have shown promise in this area are substituted Schiff base complexes of nickel, zinc, vanadium and other metals. The work presented here seeks to further explore the potential of nickel(II) Schiff base complexes as selective qDNA binders, and therefore as inhibitors of telomerase. We are using a combination of techniques, including electrospray ionisation mass spectrometry, circular dichroism and NMR spectroscopies, and fluorescence resonance energy transfer, to examine the effects of varying the structure of nickel Schiff base complexes on their ability to bind to both unimolecular and tetramolecular DNA structures. These studies have revealed that complex (1), featuring a meso-1,2-diphenylethylenediamine moiety, has a significant ability to bind to tetramolecular DNA quadruplexes, but exhibits almost no affinity towards duplex DNA.

DNA + 1 drug 100

quadruplex DNA N N Ni DNA + 2 drugs (a) O O (c) O O

DNA + 1 drug N (1) N DNA + 2 drugs

0

DNA 100

Relative Intensity (%) duplex DNA

(b) (d)

DNA (1) DNA + 1 drug 0 1600 1700 1800 1900 2000 2100 2200 2300 2400 2500 m/z Figure 1. (a) Chemdraw structure of (1); (b) X-ray crystal structure of (1); (c) ESI mass spectrum of a solution containing a 3:1 ratio of (1) and a tetramolecular DNA quadruplex; and (d) ESI mass spectrum of a solution containing a 3:1 ratio of (1) and a duplex DNA molecule.

References 1. G.L. Patrick, An Introduction to Medicinal Chemistry, 4th edition, 2009, Oxford University Press, New York. 2. E.H. Blackburn, Cell. 2001, 106, 661. 3. N.W. Kim, M.A. Piatyszek, K.R. Prowse, C.B. Harley, M.D. West, P.L.C. Ho, G.M. Coviello, W.E. Wright, S.L. Weinrich, J. W. Shay, Specific Association of Human Telomerase Activity with Immortal Cells and Cancer, Science, 1994, 266, 2011.

SL4G The antimicrobial activity of inert oligonuclear polypyridylruthenium(II) complexes against pathogenic bacteria

F. Richard Keene,a,b F. Li,c J. Grant Collins,c Jeffrey M. Warnerd and Marshall Feterld a School of Pharmacy & Molecular Sciences, James Cook University, Townsville 4811, Australia b School of Chemistry & Physics, University of Adelaide, Adelaide 5005, Australia c School of Physical, Environmental & Mathematical Sciences, UNSW Canberra 2600, Australia d School of Veterinary & Biomedical Sciences, James Cook University, Townsville 4811, Australia

Email: [email protected] .

The development of antimicrobials has been one of the major advances in medical science, but a consequence of their widespread use has been the development of drug-resistant populations of bacteria. Infection by these organisms is emerging as an important cause of morbidity and mortality worldwide: a recent update from the Infectious Diseases Society of America,1 listed (inter alia) Pseudomonas aeruginosa (P. aeruginosa) and methicillin-resistant Staphylococcus aureus (MRSA) as pathogens showing rapidly increasing rates of infection. There is clearly a need for the development of new antimicrobials; but perhaps more importantly the need for the development of new classes of antimicrobials that may not be as susceptible to the bacterial mechanisms of resistance developed against the current range of drugs.

The structure of the dinuclear polypyridylruthenium(II) complexes Rubbn, where n = 2 , 5, 7, 10, 12, 14 and 16

In this study we have examined the antimicrobial activity of an extensive range of mono-, di- and oligonuclear inert polypyridylruthenium(II) complexes against a library of bacteria, but extensively against two Gram positive (fully susceptible ATCC 25923 S. aureus and a wild type, clinical MRSA) and two Gram negative (ATCC 25922 E. coli and ATCC 27853 P. aeruginosa) strains. Studies using the inert ligand-bridged dinuclear species Rubbn in which the metals were linked by long flexible alkane chains demonstrated they were highly active against S. aureus, MRSA, E. coli and P. aeruginosa bacteria but were relatively selective between bacterial and eukaryotic cells showing low levels of toxicity against human cell lines.2

The presentation will report our investigations of the mechanism and the extent of the cellular uptake for these complexes by the bacteria, the nature of the localisation in the bacteria cells, and the effect of the complexes on the bacterial membrane permeability and electrical polarisation.3,4 Of particular note is the observed preferential binding of RNA over DNA in live cells.5

References 1. H.W. Boucher, G.H. Talbot, J.S. Bradley, J.E. Jr Edwards, D. Gilbert, L.B. Rice, M. Scheld, B. Spellberg, J. Bartlett, IDSA Report on Development Pipeline 2009, 48, 1. 2. F. Li, Y. Mulyana, M. Feterl, J. Warner, J.G. Collins, F.R. Keene, Dalton Trans. 2011, 40, 5032. 3. F. Li, M. Feterl, Y. Mulyana, J.M. Warner, J.G. Collins, F.R. Keene, J. Antimicrob. Chemother. 2012, 67, 2686. 4. F. Li, M. Feterl, J.M. Warner, F.R. Keene, J.G. Collins, J. Antimicrob. Chemother. 2013; DOI: 10.1093/jac/dkt279. 5. F. Li, E. Harry, A. Bottomley, M.D. Edstein, G. Birrell, C.E. Woodward, F.R. Keene, J.G. Collins, submitted for publication.

SL4H Biological Activities of Anti-Diabetic Transition Metals (Chromium, Vanadium, Molybdenum, and Tungsten)

Anna Safitri*, Aviva Levina* and Peter A. Lay*

School of Chemistry, The University of Sydney, 2006, Australia

Email : [email protected], [email protected]

The prevalence of diabetes, particularly with respect to type 2 diabetes, has reached epidemic proportions and continues to grow worldwide. One of the potential therapeutic targets in the treatment of type 2 diabetes involves the role of protein tyrosine phosphatases in the negative regulation of insulin signalling. The complexes of V(V/IV), Cr(III), W(VI), and Mo(VI), have all been proposed as possible drugs in the treatment of diabetes mellitus.1 Anti-diabetic activities of V(V/IV), Cr(III), Mo(VI), and W(VI) compounds are likely to be based on similar mechanisms,2 which involve phosphorylation/dephosphorylation reactions in the glucose uptake and metabolism. In order to clearly understand biological activities and phosphorylation/dephosphorylation reactions involved in anti-diabetic actions of Cr(III), V(V/IV), Mo(VI), and W(VI) complexes, the current research involves the use of cultured insulin-sensitive cells treated with these compounds. These reactions were investigated through vibrational spectroscopy. Protein phosphorylation/dephosphorylation induced conformational changes in secondary protein structure from α-helix to β- sheet, and these changes were detected by the IR spectra, which showed changes in the wavenumber and intensities of signals within the composite protein amide I band.3 The activities of anti-diabetic drugs in cultured cells were also followed by dynamic cell assays, which involve the investigation of the rates of cellular O2 consumption and proton (H+) production in glucose metabolism pathway using a Seahorse XF Extracellular Flux Analyser.

References 1. Thompson, K. H.; Chiles, J.; Yuen, V. G.; Tse, J.; McNeill, J. H.; Orvig, C. J. Inorg. Biochem. 2004, 98, 683-690. 2. Levina, A.; Lay, P. A. Dalton Trans. 2011, 40, 11675-11686. 3. Nauman, D. Appl. Spec. Rev. 2001, 36, 239-298.

SL5F Strategies for Improving Sensitised Ln(III) Luminescence in the Visible and NIR.

Evan G. Moore and Paola Ceroni

School of Chemistry and Molecular Biosciences, University of Queensland, 4072, Australia.

Email: [email protected]

Trivalent Lanthanide complexes continues to attract significant literature interest, particularly with EuIII and TbIII, due to their use as luminescent probes in biotechnology.[1] More recently, emission from YbIII and NdIII has been explored, as these cations display emission in the Near Infra-Red (NIR) region and may therefore be useful for the further development of optical NIR tomography and imaging.

Using femtosecond transient absorption spectroscopy, we have shown the efficiency of the energy transfer step from the excited triplet state of a bound organic ligand to the metal centered excited state is critical for the overall luminescence performance, and can occur with kinetics spanning from the picosecond to microsecond time domain, depending on the identity of the complexed Ln(III) cation.

With this knowledge, we have designed several new chromophore containing ligands with differing topologies in an attempt to improve the overall luminescence performance of visible and NIR emitting cations. Our recent results using both polymer based (dendrimeric) antennae and/or visible absorbing metal centred (3MLCT) excited states as a sensitiser will be reported.

Schematic of a polymeric chromophore (left) or metal based antennae (right) for sensitised Ln(III) emission

Acknowledgements We thank the Australian Research Council (FT100100795) and the Research Executive Agency of the European Commission (FP7-2010-IIF-275606) for financial support.

Reference 1. Bünzli, J-C. G., Chem. Rev., 2010, 110, 2729-2755.

SL5G Luminescence lanthanide complexes for imaging of key cell cycle regulators and inhibition of cancer cells

Hongguang Li,a Rongfeng Lan,a Chi-Fai Chan,a Lijun Jiang,a Wai-Lun Chan,a Steve Cobb,b and Ka-Leung Wong*,a

a Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR b Department of Chemistry, Durham University, Durham, UK, DH1 3LE

Email: [email protected]

Polo-like kinase 1 (Plk1), involved in many key steps throughout mitosis, is found to be of great important in cancer treatment since its activity appears to be limited to mitosis in proliferating cells. However, the lack of selective small- molecule inhibitors of the kinase remains a major obstacle to further elucidate its precise functions. For instance, using anticancer agents that target microtubules may engender various adverse effects partially because of the diverse functions of microtubules in the cell. To date, only few small molecules can show the very specificity to Plk1 for imaging and inhibition. It is self-evident that the enhanced understanding of Plk1 activities will considerably favour the design and implementation of future experiments in the research, preclinical, and clinical settings, adding muscle to our war against cancer.

Although decent prognosis can be achieved by these small molecules, such chemosensors (i.e. BI 2536) are not without disadvantages: broad emission bands, short luminescence lifetimes (~ns) and ease of photo-bleaching. In contrast, lanthanide complexes, in this regard, do surpass all their counterparts, having large Stokes shifts, sharper fingerprint emission peaks, longer emission lifetimes (~ms) and higher photo-stability. Our blueprint includes the cyclin-specific lanthanide complexes with particular peptides and chromophores that can be excited in the near infra-red region via multi-photon excitation, and, above all, be Plk1-specific.

In this presentation, it will show our development of a new generation of lanthanide complexes conjugated with responsive chromophores and Plk1 specific peptides as dual probes – imaging and anti-tumor. It is hoped that the success in research could also lead to the success in practice, thereby providing more powerful tools to get a more complete picture of the role of Plk1 kinase.

References 1. T. Zhang, C.-F. Chan, R. Lan, H. Li, N.-K. Mak, W.-K. Wong, K.-L.Wong, Chem. Comm., 2013, 49, 7252. 2. H. Li, F. L. Chadbourne, R. Lan, C.-F. Chan, W.-L. Chan, G.-L. Law, C.-S. Lee, S. L. Cobb, K.-L. Wong, Dalton Trans., 2013, 42, 13495. 3. J.-X. Zhang, H. Li, C.-F. Chan, R. Lan, W.-L. Chan, G.-L. Law, W.-K. Wong, K.-L. Wong, Chem. Commun., 2012, 48, 9646. 4. H.-K. Kong, F. L Chadbourne, G.-L. Law, C. Y.-T. Ko, H.-L. Tam, S. L. Cobb, C.-K. Lau, C.-S. Lee, K.-L. Wong, Chem. Commun., 2011, 47, 80524. 5. T. Zhang, X. Zhu, W.-M. Kwok, C. T.-L. Chan, H.-L. Tam, W.-K. Wong, K.-L. Wong, J. Am. Chem. Soc., 2011, 50, 20120.

SL5H Lanthanides and Calixarenes in Soft Matter

M. I. Ogden,1 T. Becker,1 C. Driscoll,1 C. Y. Goh,1 F. Jones,1 M. Massi,1 M. Mocerino,1 and B. W. Skelton.2

1Department of Chemistry, Curtin University, Bentley, WA, 6102 2CMCA, University of Western Australia, Crawley, WA, 6009

Email: [email protected] . We have recently been studying the interaction of appropriately functionalized calixarenes with lanthanide cations, contained within soft materials. These include hydrogels,1,2 where the presence of the calixarene and metal cation induces the formation of the materials, and polymeric systems3,4 where the lanthanide complex adds functionality.

Our focus in this work is to use these readily modified systems to better understand the fundamental behaviour of these materials. We will present our efforts to investigate the dynamics of hydrogelation processes using in situ atomic force microscopy, exploiting the fact that the hydrogel properties can be finely tuned by changing the composition and concentration of the salt added to trigger gelation. We will also discuss our attempts to incorporate different calixarene ionophores into PMMA to produce more effective light emitting materials.

References 1. T. Becker, C.Y. Goh, F. Jones, M.J. McIldowie, M. Mocerino and M.I. Ogden, Chem. Commun., 2008, 3900. 2. C.Y. Goh, T. Becker, D.H. Brown, B.W. Skelton, F. Jones, M. Mocerino, and M.I. Ogden, Chem. Commun., 2011, 47, 6057. 3. C.R. Driscoll, B.L. Reid, M.J. McIldowie, S. Muzzioli, G.L. Nealon, B.W. Skelton, S. Stagni, D.H. Brown, M. Massi, and M.I. Ogden, Chem. Commun., 2011, 47, 3876. 4. B.W. Ennis, S. Muzzioli, B.L. Reid, D.M. D’Alessio, S. Stagni, D.H. Brown, M.I. Ogden and M. Massi, Dalton Trans., 2013, 42, 6894.

SL6G Ag(2+) – an anomalously strong spin polarizer in solids

Wojciech Grochala

Faculty of Chemistry and Centre for New Technologies, University of Warsaw, 02093, Poland

Email: [email protected]

Paramagnetic Ag(2+) cations are contained in over 100 distinct chemical compounds, mostly fluorides [1]. Ag(2+) is isoelectronic to its lighter congener, Cu(2+), but the former is much more powerful oxidizer than the latter, as testified by the values of the standard redox potential for the M(2+)/M(1+) redox pairs: +1.98 V for Ag, +0.16 V for Cu (E0 values are vs. NHE). This is one reason why the chemistry of Ag(2+) with O- [2,3,4] and N- ligands [5,6,7] – which are more prone to oxidation that F– anions – is rather limited. The electronic and magnetic properties of the F-, O- and N- compounds of Ag(2+) which exhibit 1- or 2-dimensional character, are currently of interest [8,9]. In particular, a possibility of generating of a novel family of high-temperature superconductors based on Ag(2+) compounds, has been proposed [1,10]. Indeed, Ag(2+) cations are electron-greedy and they exert extremely strong spin-polarizing influence on the neighbouring ligands thus introducing substantial local spin densities on atoms of nonmetals – even on fluorine [2,3,4,5,7,8]. This is due to facile mixing of the Ag 4d valence orbitals (deep-lying in the energy scale) with the nonmetal 2p orbitals. Covalence of the metal–nonmetal bonding is pronounced even for the Ag–F bonds, as testified by the XPS spectroscopy [11] and confirmed by the theoretical calculations [1]. The facile orbital interactions lead to very large absolute values of the magnetic superexchange constants (J) in 1D or 2D ‘magnetically dense’ solids. For example, J value for AgSO4 (1D antiferromagnet) is –18.7 meV (–217 K) [2] which is similar to that for NiO (–19 meV) despite the presence of the much longer O–S–O bridge between Ag(2+) cations than the –O– one between Ni(2+) cations, and despite twice smaller number of unpaired electrons for Ag(2+) than for high-spin Ni(2+) (1 : 2). The recently investigated KAgF3 (figure) exhibits the record large absolute value of J among all fluorides materials known, ca. –97 meV for the HT phase and ca. –106 meV for the LT one [12]. The theoretical calculations for the HT phase yield J = –125 meV, in fair agreement with experiment. Fluoroargentates(II) now rank second – after oxocuprates(II) – as far as J values for diverse families of magnetic materials are considered.

– Crystal structure of the LT phase of KAgF3 with emphasis on the presence of 1D [AgF2+2/2] chains. Acknowledgements: Author thanks all collaborators in this research, in particular Dr Zoran Mazej (IJS, Ljubljana, Slovenia) and he acknowledges financing from the Polish National Science Centre (NCN), grant AgCENT No.2011/01/B/ST5/06673; computational time at supercomputers was provided by ICM UW (G34-10). References 1. W. Grochala, R. Hoffmann, Angew. Chem. Int. Ed. Engl. 2001, 40, 2743. 2. P. Malinowski et al., Angew. Chem. Int. Ed. Engl. 2010, 49, 1683. 3. P. Malinowski et al., Chem. Eur. J. 2011, 17, 10524. 4. P. Malinowski et al., Cryst. Eng. Comm. 2011, 13, 6871. 5. J. L. Manson et al., J. Am. Chem. Soc. 2009, 131, 4590. 6. P. J. Leszczyński et al., Dalton Trans. 2012, 41, 396. 7. J. L. Manson et al., Inorg. Chem. 2012, 51, 1989. 8. S. McLain et al., Nature Mater. 2006, 5, 561. 9. W. Grochala, Nature Mater. 2006, 5, 513. 10. W. Grochala, J. Mater. Chem. 2009, 51, 1989. 11. W. Grochala et al., ChemPhysChem 2003, 4, 997. 12. D. Kurzydłowski et al., Chem. Comm. 2013, 49, 6262.

SL6G Non-Reciprocal Directional Dichroism in Copper Oxides

Mark J. Riley and Myles Atkinson

School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, 4072, Australia.

Email: [email protected]

Copper metaborate (CuB2O4) has recently been the subject of numerous studies due to its unusual magnetic and optical properties. The crystal contains two types of Cu(II) sites each coordinated to four oxygen atoms in a planar arrangement. The interaction between the paramagnetic Cu(II) ions results in a rich series of magnetic phase transitions as the temperature is lowered, starting with antiferromagnetic ordering at TN = 21 K. Both Cu(II) sites give rise to very sharp optical d-d transitions in the visible region. The half-width at half-height of the electronic origins are of the order 8 cm-1, unusually sharp for Cu(II) compounds. Combined magneto-optical studies have led to further surprises. These include “giant” optical magneto-electric effects such as a non-reciprocal directional dichroism, and a claimed magnetic control of crystal chirality [1]. The former effect is the dependence of the light transmission on the direction of the magnetic field perpendicular to the light direction. For example, for light directed along [110] (k||[110], E||[110]) and a 0.05 Tesla magnetic field oriented along [110], the absorption increases by over 100% when the field direction is reversed. Such properties have a clear � � technological importance for use in devices that control properties of light; recent examples of CuB2O4 used as a magnetic controllable phase retarder and an electric field modulation of the optically detected magnetization have been given [2]. Given the interest and potential importance of this material it is surprising that CuB2O4 has not been studied in terms of the molecular origin of the observed unusual properties. Recently Pisarev et al. [3] have made an important contribution to this area by quantifying the spectra in terms of the local CuO4 excitations and have determined the ligand field parameters that reproduced the observed transition energies. However, this study raises many additional 2 questions concerning the non-observation of both the spin-orbit split components of the Eg excited state and the polarization properties of the spectrum. In addition, it falls short of describing how the states interact with a magnetic field and providing a molecular level description of the origin of the giant non-reciprocal dichroism. In this work we provide such a description and show that it occurs through the simultaneous interaction of a magnetic and electric dipole transition moments that arise through the action of spin-orbit coupling with a very unusual ligand field for one of the CuO4 sites. At this site we will show that the energy is dominated by the CuO4 first coordination sphere (Cu-O=1.999Å) while the intensity electric dipole intensity comes from a second sphere effect of 4 oxygen atoms in a tetrahedral arrangement (Cu-O=2.864Å).

z O4

Cu O1 z O4 O1 x y Cu-O1=1.964Å y Cu-O4=2.829Å x

References 1. M. Saito, et al., Phys. Rev. Lett. 2008, 101, 117402 2. M. Saito, et al., Nature Materials, 2009, 8, 634. 3. R. V. Pisarev, et al., Phys. Rev. B, 2011, 84, 075160.

SL6H Dominance of ILCT Transitions over MLCT in Amine-Substituted DPPZ Complexes

Christopher B. Larsen, Holly van der Salm, Nigel T. Lucas and Keith C. Gordon

Department of Chemistry, University of Otago, 9016, New Zealand.

Email: [email protected]

Dipyridophenazine (dppz) and its complexes have been extensively studied due to their interesting photophysical properties.1 These are derived from the presence of two spatially segregated, close-lying acceptor orbitals on the ligand. Metal to ligand charge transfer (MLCT) processes to these orbitals result in very different photophysical behaviours, with the MLCT transition that terminates on the phenanthroline based part of the molecule (rings A, B and C) being emissive, and the MLCT transition that terminates on the phenazine based part of the molecule (rings B, D and E) being non-emissive.2 Population of these two MLCT states can be controlled using the chemical environment, and this is the 2+ basis for the “molecular light-switch” effect, in which [Ru(bpy)2(dppz)] is emissive in aprotic solvent and in the presence of DNA and non-emissive in protic solvent.3

We present an amine-appended dppz ligand and its Cu(I), Re(I), Ru(II), Pt(II) and Ir(III) complexes, all of which demonstrate dominance of intraligand-charge transfer (ILCT) processes over MLCT transitions. This behaviour is unprecedented in dppz systems (and other phenanthroline-based complexes), and results in some unusual properties that we characterise using electrochemistry, absorbance, emission, transient absorbance, resonance Raman and time- resolved infrared spectroscopies, resonance Raman excitation profiles, and model using TD-DFT calculations.

References 1. Amouyal, E.; Homsi, A.; Chambron, J.-C.; Sauvage, J.-P. J. Chem. Soc., Dalton Trans. 1990, 1841 2. Fees, J.; Kaim, W.; Moscherosch, M.; Matheis, W.; Klims, J.; Krejcik, M.; Zalis, S. Inorg. Chem. 1993, 32, 166 3. Friedman, A. E.; Chambron, J. C.; Sauvage, J. P.; Turro, N. J.; Barton, J. K. J. Am. Chem. Soc. 1990, 112, 4960

SL7A III III {Cr 2Dy 2} single-molecule magnets: Enhancing the blocking temperature via 3-d magnetic exchange

Keith S. Murray,a Stuart K. Langley,a Daniel P. Wielechowski,a Veacheslav Vieru,b Nicholas F. Chilton,c Boujemaa Moubaraki,a Brendan F. Abrahams,d Liviu F. Chibotarub

aSchool of Chemistry, Monash University, Clayton, Victoria 3800 Australia; bTheory of Nanomaterials Group and INPAC - Institute of Nanoscale Physics and Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200F, 3001 Heverlee, Belgium; c School of Chemistry, University of Manchester, Manchester M13 9PL, U.K.; d School of Chemistry, The University of Melbourne, Victoria 3010, Australia.

Email: [email protected] . The use of anisotropic lanthanide(III) ions, such as Dy(III), in single molecule magnets (SMMs), either in homometallic species or in mixed d-f-block clusters, has given much recent impetus to the subject that began III/IV when the iconic d-block Mn 12-acetate cluster was found to exhibit slow magnetization relaxation, stepped hysteresis and other quantum effects, below the so-called blocking temperature. We describe here the use of isotropic Cr(III) centres, with anisotropic Dy(III) centres, in a series of tetranuclear ‘butterfly’ clusters of type III III 2- 1 [Cr 2Dy 2(OMe)2(O2CPh)4(mdea)2(NO3)2], 1, where mdea = methyldiethanolatoamine. This example is III III isostructural with the Co(III) analogue [Co 2Dy 2(OMe)2(O2CPh)4(mdea)2(NO3)2], 2, in which the Co(III) centres are diamagnetic, such clusters exhibiting SMM behaviour (Ueff = 78.9 K) and quantum tunneling (QTM) below 2 K.2 Complex 1 displays some fascinating SMM behaviour, such as stepped hysteresis between 1.8 K and 3.5 K (Figure, right) observed using normal Squid magnetometers (and not seen for 2), a Ueff of 77 K and a long relaxation time. Ab initio calculations are described that reveal anisotropy directions (Figure, left), important Dy..Dy, Dy..Cr and Cr..Cr exchange coupling constants and the resulting exchange spectrum. The activation barrier in 1 is of the multiexchange type and this contrasts with that in 2 in which it originates from one excited state on individual Dy ions. Variation in coligands in 1 leads to subtle and intriguing changes in SMM properties.

References 1. S. K. Langley, D. Wielechowski, V. Vieru, N. F. Chilton, B. Moubaraki, B. F. Abrahams, L. F. Chibotaru and K. S. Murray, Angew. Chem. Int. Ed., 2013, in press. DOI: 10.1002/ange.201306329 2. S. K. Langley, L.Ungur, N. F. Chilton, B. Moubaraki, W. Wernsdorfer, L. F. Chibotaru and K. S. Murray, unpublished data,

71

SL7B Multistable Spin Crossover in Flexible Coordination Polymers

Suzanne Neville, Natasha Sciortino, Florence Ragon, Maximillian Klein and Cameron Kepert

School of Chemistry, The University of Sydney, 2006, Australia.

Email: [email protected] . Porous host-guest active materials (i.e. metal-organic frameworks (MOFs) or porous coordination polymers (PCSs)) are attracting much attention owing to their readily designable metal centres and pores to delivery desired properties (i.e. CO2 capture, catalysis, magnetism). The incorporation of spin crossover (SCO) centres into porous framework materials has opened up a new field of functional materials research for which a spin switching response (i.e. temperature, pressure, light) can additionally be modulated by host-guest chemistry for sensory and memory functionality. Within this category of material which display guest-dependent SCO are a II II family of spin crossover 2-D and 3-D Hofmann-like SCO complexes of the type [Fe (L)M (CN)4]·(guest) (L = mono- or bis- pyridyl-based ligands, MII = Pt, Pd, Ni) which show dramatic guest-related phenomena. The organic linkers (3-D Hofmann-materials) or interlayer spacers (2-D Hofmann-materials) allow functional components to be incorporated with deliberate host-host or host-guest interaction sites or ligand length variability to increase surface area thus providing an overall versatile tool for designing advanced functionality in SCO materials. We show that mono-4-functionalised 1,2,4-triazole ligands provide cooperative spin transitions in 2-D Hofmann-like materials, opening an avenue for systematic functionalisation of the pore surface to enhance cooperativity through host-host and host-guest interactions. Furthermore, the binding mode of the 1,2,4-triazole provides an inherent asymmetry to the ligand which provides reliable access to multistability through the generation of inequivalence in iron(II) sites.

72

SL7C Solvent Effects on the Structural and Magnetic Properties of Spin Crossover III [Fe (qsal-I)2]CF3SO3·Solvent Complexes

Wasinee Phonsri,a David J. Harding,a Phimphaka Harding,a Keith S. Murray,b Boujemaa Moubaraki,b Lujia Liuc and Shane G. Telferc

aMolecular Technology Research Unit, School of Science, Walailak University, Thasala, Nakhon Si Thammarat, 80161, Thailand bSchool of Chemistry, Monash University, Clayton, Victoria, 3800, Australia cMacDiarmid Institute for Advanced Materials and Nanotechnology, Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand

Email: [email protected]

Spin crossover complexes remain fascinating systems for the development of molecular materials. In the quest for new spin crossover systems we have prepared the series [Fe(qsal-I)2]CF3SO3·Solvent (Solvent = MeOH, EtOH, IPA, MeCN and acetone). The compounds all crystallize in the same space group, triclinic P1̅ with the + - asymmetric units are composed of [Fe(qsal-I)2] , CF3SO3 and a single solvent molecule. Interestingly SCO behaviour is significantly modified by the solvent with abrupt and wide hysteretic spin crossover in the MeOH and EtOH systems, respectively. Variable temperature single crystal data confirm the structural changes occurring during the spin transitions. Correlations between the crystal structures and magnetic properties are discussed.

Figure 1 Structure of [Fe(qsal-I)2]CF3SO3 and χMT vs. T plot for [Fe(qsal-I)2]CF3SO3·Solvent complexes where the solvent is MeOH and EtOH.

References 1. D. J. Harding, W. Phonsri, P. Harding, I. A. Gass, K. S. Murray, B. Moubaraki, J. D. Cashion, L. Liu and S. G. Telfer, Chem. Commun., 2013, 49, 6340. 2. D. J. Harding, D. Sertphon, P. Harding, K. S. Murray, B. Moubaraki, J. D. Cashion and H. Adams, Chem. Eur. J., 2013, 19, 1082. 3. S. Hayami, Z. Gu, H. Yoshiki, A. Fujishima and O. Sato, J. Am. Chem. Soc. 2001, 123, 11644.

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SL7D Small Cyano Anions: Chemical Swiss Army Knives

Stuart R. Batten

School of Chemistry, Monash University 3800, Australia.

Email: [email protected] . Small cyano anions (SCAs) have proven to be remarkably versatile building blocks for a wide range of applications.1 The parent anions are easily synthesised in large quantities, and new families of anions can be made through nucleophilic addition of water, alcohols and amines to the nitrile groups. Further derivatives can also be made using new synthetic pathways involving the formation and deprotonation of cyanooximes. Once synthesised, SCAs with divergent coordination sites produce coordination polymers which show magnetic ordering and gas sorption. Derivatives containing both divergent and convergent sites have proven particularly effective at producing homometallic and heterometallic clusters for investigation as Single Molecule Magnets; nuclearities include Mn3, Mn4, Mn8, Fe8, Cu3, Gd7, Dy7, Dy8, Ln13, Ln14, TM2Ln, TMLn2, and TM2Ln2. Novel hydrogen bonding networks, including new “Heterotapes”, are produced by anions such as carbamoyldicyanomethanide (cdm). New ionic liquids can be made with the anionic component consisting of 3- either the SCAs themselves, or lanthanoid complexes such as Ln(dcnm)6 .

Reference 1. D.R. Turner, A.S.R. Chesman, K.S. Murray, G.B. Deacon, S.R. Batten, Chem. Commun. 2011, 47, 10189.

74

SL8A Highly-Reactive Phosphorus Building Blocks – New Concepts in Synthesis

Jan J. Weigand

Department of Chemistry and Food Chemistry, TU Dresden, 01062 Dresden, Germany.

Email: [email protected].

Fundamental research allows us to find new, economically and ecologically attractive ways to meet current challenges. The uncertainty of available phosphorus resources is an urgent concern. Unlike oil, which is lost once used, phosphorus can be recovered and used over and over again or at least transformed into other P- compounds of chemical use. The intention of our research is to contribute to the field of synthetic chemistry both, inorganic and organic, by identifying and developing highly-reactive phosphorus reagents that can be potentially regenerated. In particular, we are interested in Weiss-type compounds[1] which are containing N– (12+, 23+) or C–based (32+, 43+) ligands (Scheme).[2,3]

We are entering new avenues of phosphorus chemistry and address fundamental questions to develop new applications which can also be extended to the heavier group 15 congeners. Using novel and powerful phosphorus reagents, new concepts for more efficient, selective and sustainable synthetic procedures are developed.[4] Our research also intends to develop greener and more efficient processes and, whenever possible, to recover the phosphorus after the reaction. Thus, novel phosphorus-based compounds can be used in the recovery of industrial waste by-products such as phosphane oxides and, therefore, have a positive impact on certain chemical industries and the environment.[5]

Keywords: main-group chemistry, phosphorus chemistry, sustainable synthetic procedures, synthetic reagents and methods

References 1. Weiss, R.; Engel, S. Synthesis, 1991, 1077-1078; b) Weiss, R.; Engel, S. Angew. Chem. Int. Ed. Engl., 1992, 31, 216-218. 2. Feldmann, K.-O.; Weigand, J. J. Angew. Chem. Int. Ed., 2012, 51, 6566-6568 3. Weigand, J. J.; Feldmann, K.-O.; Henne, F. D. J. Am. Chem. Soc., 2010, 132, 16321-16323. 4. Weigand, J. J.; Feldmann, K.-O.; Echterhoff, A. K. C.; Ehlers, A.; Lammertsma, K. Angew. Chem. Int. Ed., 2010, 49, 6178-6181. 5. Feldmann, K.-O.; Schulz, S.; Klotter, F.; Weigand, J. J. ChemSusChem, 2011, 4, 1805-1812.

75

SL8B Alkali-Metal-Mediated Methane Elimination: a bond breaking conundrum

Victoria L. Blair, Philip R. Andrews, Emily C. Border, Christopher D.Thompson

School of Chemistry, Monash University, Clayton, Melbourne VIC 3800.

Email: [email protected]

Despite their wide spread use in organic synthesis, the structural chemistry of Group 1 metal amides continue to spring many interesting and unexpected surprises adopting a plethora of aggregation states and structural motifs highly dependent on solvent and Lewis base choice.1-3 While the majority of solid-state and solution studies on metal amides produce few surprises, in recent years, we have demonstrated that anion rearrangements and unusual structures can result, even from simple and commonly used chiral and achiral amines.5, 6

Here we present a systematic study on the metallation and aza-allyl transformations of (S)-α-mbba and its reaction with nBuM (M = Li, Na or K) and various Lewis donors including THF, TMEDA, PMDETA and HMPA (where THF = tetrahydrofuran; TMEDA = N,N,N’,N’-tetramethylenediamine; PMDETA = N,N,N’,N’,N’’-pentamethyldiethylenetriamine; HMPA = hexamethylphoshoramide). We report the formation and analysis of six new metallated complexes of which five have been successfully characterised in the solid state via single-crystal X-ray diffraction studies. Solution studies of the metallated complexes reveal a secondary co-product, 1, 3-diphenyl-2-azaallyl leaving the conundrum where has the CH3 gone?

Me Me nBuM, hexane N N H 25°C M n

Donor D = donor = TMEDA or 3 THF, or PMDETA 25°C

Me H H H

N N + M.D M.D

References 1. Sott, R.; Granander, J.; Williamson, C.; Hilmersson, G. Chem. Eur. J. 2005, 11, 4785. 2. Willard, P. G.; Sun, C. J. Am. Chem. Soc. 1997, 119, 11693. 3. Sott, R.; Hakansson, M.; Hilmerson, G. Organometallica 2006, 25, 6047. 4. Andrews, P. C.; Duggan, P. J.; Fallon, G. D.; McCarthy, T. D.; Peatt, A. C. J. Chem. Soc., Dalton Trans. 2000, 2505. 5. Andrews, P. C.; Duggan, P. J.; Fallon, G. D.; McCarthy, T. D.; Peatt, A. C. J. Chem. Soc., Dalton Trans. 2000, 1937.

76

SL8C Pseudo solid state synthesis in metal-organic chemistry

Glen B. Deacon, Peter C. Junk and Aron Urbatsch.

School of Chemistry, Monash University, Victoria 3800, Australia

Email: [email protected]

Metal 8-quinolates (oxinates) have a long history in analytical chemistry. Their insolubility has enabled them to be used extensively as gravimetric reagents, and a combination of their insolubility with titration of the ligand has provided a volumetric method for metal analysis. Their insolubility (often as amorphous precipitates) has been a frustration in structure determination, particularly for rare earth complexes. Although, derivatisation has been used to induce solubility, the challenge remains for the parent 8-quinolinolate (OQ) and the simple 2- methyl-8-quinolinolate derivative (MQ), We have adopted a pseudo solid state synthesis approach, particularly to give heterobimetallic complexes with Ae/Ln, TM/Ln, and alkali metal (AM)/Ln combinations. Thus heating a mixture of metals or an alloy with HOQ or HMQ at elevated temperatures has enabled single crystals to be grown and structures determined. Even more profitable have been rearrangement reactions between mixtures of metal oxinates at elevated temperatures in fluxes of 1,2,4,5-tetramethylbenzene or 1,3,5-tri-tert-butylbenzene giving complexes such as Ln2Ae(OQ or MQ)8, Ln2TM(OQ or MQ)8, LnTM2(OQ or MQ)7, AMLn(OQ or MQ)4. Some heteroleptic complexes incorporating carbonate etc have also been obtained, not always by design. Overall this pseudo solid state synthetic approach has provided a rich structural chemistry of a common and long known ligand system

77

SL8D Catalytic Application of Low-Coordinate Group 14(II) Hydrides

Terrance Hadlington, Cameron Jones*

School of Chemistry, Monash University, Clayton 3800, Australia.

Email: [email protected]; [email protected] . Recent developments in the study of the main-group elements has taken the rather dormant field to one of great interest and diverse chemistries. Of these, low-oxidation state and low-coordinate systems are of particular interest due to similarities with transition metal complexes in their reactivity.1 In order to stabilize such systems, extremely bulky monoanionic ligands have been employed, such as the terphenyl systems developed by Power and the more recent bulky amido ligands developed in the Jones group. These ligands are capable of stabilizing numerous main-group systems which are generally highly reactive, and have even been shown to activate small- 2 molecules such as CO2 and H2. The latter reaction utilizing the germanium(I) system developed by the Jones group occurs at low pressures and temperatures, and even in the solid state.2b Where the bulky ligand † - (iPr)3SiAr N is used (see below) the resulting germylene hydride, which is dimeric in the solid state, has been shown to exist in equilibrium with a monomeric species in solution.3 The same has been shown for the tin(II) based system using the same ligand. These hydride species are highly reactive towards organic unsaturates such as alkenes and carbonyl compounds, and in some circumstances these reactions are reversible. This display of reactivity has been extended to catalysis, with the first examples of a group 14 complex achieving the catalytic hydroboration of ketones and aldehydes, with turn over frequencies being comparable to previous examples which rely on expensive and toxic late transition metal system.

References 1. (a) P. P. Power, Nature, 2010, 463, 171; (b) M. Asay, C. Jones, M. Driess, Chem. Rev., 2011, 111, 354. 2. (a) G. H. Spikes, J. C. Fettinger, P. P. Power, J. Am. Chem. Soc., 2005, 127, 12232; (b) J. Li, C. Schenk, C. Goedecke, G. Frenking, C. Jones, J. Am. Chem. Soc., 2011, 133, 18622; (c) J. Li, M. Hermann, G. Frenking, C. Jones, Angew. Chem. Int. Ed., 2012, 51, 8611. 3. T. J. Hadlington, M. Hermann, J. Li, G. Frenking, C. Jones, Angew. Chem. Int Ed., 2013, 52, 10199.

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SL9A Metal Alkoxide Molecular Precursors towards Solution Processed transparent InGaZnO semiconductors

Kulbinder K. Banger, Josephine Socratous, Tim Leedham and Henning Sirringhaus

Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge, CB3 0HE, UK.

Email: [email protected]

Ternary and quaternary amorphous mixed metal oxides are emerging as high performance semiconductors for thin film transistor applications, with gallium-doped InGaZnO (IGZO) being one of the most widely studied and best performing systems.1 A major research and development focus has been on alternatives to amorphous/polycrystalline silicon.1,2 Although most work on mixed metal oxides has focused on vacuum- based deposition processes, such as sputtering,2 solution processing has emerged as a viable alternative that produces materials of comparable device performance and stability.3 Hence one of the key features of a solution driven process, suitable for printed electronics is the design and choice of suitable molecular precursors.

Here, we investigate molecular alkoxide metal clusters derivatives which can undergo condensation and elimination reaction mechanism to afford an amorphous solid-state mixed metal oxide layers, Scheme.1

M(OR)x + H2O M(OR)x-1(OH) + HOR

2M(OR)x-1OH M2O(OR)2x-2 + H2O

M2O(OR)2x-2 --M-O-M-- ∆H (Scheme 1) Where M= In, Zn, Ga, R = organic ligand

Solution processed oxide layers fabricated from Indium isopropoxide cluster (In5O(OCH(CH3)2)13) (1), 4 zinc bis methoxyethoxide (Zn(OCH2CH2OCH3)2) (2) and (Ga(OCH(CH3)2)3) (3) coordination derivatives, when used in a thin film transistor (TFT) device structure demonstrate excellent performance comparable to those made by vacuum sputtered processed. Electrical measurements reveal solution processed metal oxide semiconducting layers via alkoxide metal oxides precursors (1),(2),(3) , exhibit high charge carrier mobility, µ= 4- 25 cm2/Vs) and enhanced electrical stability similar to that found in vacuum sputtered IGZO TFT’s. In addition we show that we can facilitate reduced temperature processing (225-200 °C yielding mobilities up to 4.4 cm2/Vs) and demonstrate a facile ‘ink-on-demand’ process for these materials which utilizes the alcoholysis reaction of alkyl metal precursors to negate the need for complex synthesis and purification protocols.

References 1. (a) Barquinha, P., Transparent oxide electronics : from materials to devices. Wiley: Hoboken, N.J., 2012; (b) Facchetti, A.; Marks, T. J., Transparent electronics : from synthesis to applications. Wiley: Chichester, U.K., 2010; p xxi, 448 p., 4 p. of plates; (c) Wager, J. F.; Keszler, D. A.; Presley, R. E., Transparent electronics. Springer: New York, 2008; p viii, 212 p. 2. Nomura, K.; Ohta, H.; Takagi, A.; Kamiya, T.; Hirano, M.; Hosono, H., Room-temperature fabrication of transparent flexible thin-film transistors using amorphous oxide semiconductors. Nature 2004, 432 (7016), 488-492. 3. Street, R. A., Thin-Film Transistors. Advanced Materials 2009, 21 (20), 2007-2022 4. Bradley, D. C.; Chudzynska, H.; Frigo, D. M.; Hursthouse, M. B.; Mazid, M. A., A Penta-Indium Oxo Alkoxide Cluster with a Central 5-Co-Ordinate Oxygen - Preparation and X-Ray Crystal-Structure of i 2 i 3 i 5 (InoPr )5(µ- -OPr )4((µ- -OPr )4(µ -O). Journal of the Chemical Society-Chemical Communications 1988, (18), 1258-1259.

79

SL9B Inorganic materials synthesis using vortex fluidics

Ramiz A. Boulos,1 Paul K. Eggers,2 Chee Ling Tong1 and Colin L Raston1

1Centre for Nanoscale Science and Technology, School of Chemical and Physical Sciences, Flinders University, Bedford Park, SA 5042 Australia 2School of Chemistry and Biochemistry, The University of Western Australia, Crawley, WA 6009 Australia

Email: [email protected]

Controlling chemical reactivity and selectivity is at the core of gaining access to new compounds and materials. The traditional approach of carrying reactions out using batch processing can suffer from anisotropic mixing and poor heat transfer, which can result in competing reactions, and there are issues in being able to selectivity control kinetic versus thermodynamic product. To this end we have developed a low cost and modular vortex fluidic device (VFD), Figure 1(a),1 for controlling chemical reactivity and selectivity in general. The VFD allows reactions to be carried under scalable continuous flow conditions, which is significant also for down stream applications, such that the research reactor is the production reactor, bypassing the classical approach of pilot stage to production stage batch processing. In this continuous flow mode of operating the VFD, jet feeds deliver reagents to the base of the rapidly rotating tube (typically a 10 mm diameter NMR tube), with the intense micro- mixing and shear from the viscous drag as the microfluidic thin film whirls along the tube. The thin films ensures uniform heat transfer and mixing, and the waves and ripples break the surface tensions resulting in high mass transfer of gases. All molecules are treated in the same way, which can be varied by varying the VFD control parameters, namely concentrations, temperature, flow rates, tilt angle , rotational spe contact angle, as well as using field effects (magnetic, tunable laser and UV). The application of the VFD operating under the continuous flow mode in inorganic chemistry will be presented, and will include: (i) the synthesis of mesoporous silica at room temperature, with the ability to control the pore size arising from the shear on the Pluronic P123 micelles,2 (ii) controlling the polymorphs of calcium carbonate, Fig.1(b), (iii) preparing MOFs, controlling the different products, as well as particle size and shape, and more. The VFD is also effective in generating thin films with intense shear for finite volumes of liquid for tilt angles ≥ 0o, as a confined mode of operation.1 Thus the VFD can be used for scaling up or scaling down under intense shear. Examples of the application of the confined mode include: exfoliating graphite and h-BN (Fig. 1(c)3 and controlling the size of metal nano-particles on graphitic material (graphene, nanotubes and nano-onions).4

Figure 1. (a) Schematic of the vortex fluidic device, (b) CaCO3 polymorphs, & (c) prisms/sheets of Zn(II) teraphthalate MOF-scale bar 1 

Acknowledgements: Support of this work by the Australian Research Council and The Government of South Australia is gratefully acknowledged. References:

1. L. Yasmin, X. Chen, K.A. Stubbs and C. L. Raston, Nature Scientific Reports, 2013, 3, 2282. 2. C. L. Tong, R. A. Boulos, C. Yu, K. S. Iyer, and C. L. Raston, RSC Advances, 2013, DOI: 10.1039/c3ra42831a. 3. X. Chen, J. F. Dobson and C. L. Raston, Chem. Commun., 2012, 48, 3703.

4. Y. A. Goh, X. Chen, et al., Chem. Commun., 2013, 49, 5171 - 5173.

80

SL9C Supercritical Fluid Electrodeposition of Germanium

David Pugh, Philip N. Bartlett, Charles Y. Cummings, William Levason, Gillian Reid and David C. Smith

Department of Chemistry, University of Southampton, Highfield, Southampton, SO17 1BJ, UK.

Email: [email protected]

The top-down nature of vapour deposition (e.g. physical/chemical vapour deposition) means it is not appropriate for growing nanowires by filling extremely small nanopores (~3 nm). There is no driving force for deposition to occur at the bottom of pores hence the neck of the pore gets blocked and nanowires cannot be grown. This can be circumvented by positioning an electrode at the bottom of a pore and using electrodeposition as a bottom-up deposition method to grow nanowires. However, most electrodeposition is carried out in a liquid solvent (H2O, MeCN etc.). These liquids are generally unsuitable for depositing material into very small (high aspect ratio) pores because their surface tension prevents the liquid from penetrating the pore and transporting the precursor to the electrode, thus nanowires at these dimensions cannot be grown using electrodeposition. Supercritical fluids are substances which are heated and pressurised beyond their critical point. Their properties combine those of liquids (such as mass transport) and gases (zero surface tension). We are developing supercritical fluid electrodeposition (SCFED) as a brand new technique for depositing a variety of materials into small nanopores.1 This technique combines the unique properties of supercritical fluids, such as zero surface tension, with a bottom-up approach to filling small nanopores using electrodeposition. Metals such as Cu have been deposited both as thin films and also into 3 nm pores, confirming that SCFED delivers nanostructured materials on an extremely small scale.2

Left: structure of [EMIM]2[GeCl6] (EMIM = 1-ethyl-3-methylimidazolium); Centre: structure of [EMIM][GeCl3]; Right: SEM image of Ge deposited inside a patterned substrate

Germanium is a very important semiconducting material for the electronics industry. Our initial n attempts at the SCFED of Ge thin films used GeCl4 as the Ge source, with Bu4N Cl as supporting electrolyte, giving poorly-adherent amorphous films with significant levels of contaminant.3 We ascertained that the n contamination most likely originated from the breakdown of the Bu4N cation under the extreme conditions used to reduce Ge(IV) to elemental Ge. In this presentation we report significant improvements on the SCFED of Ge through the synthesis of new tailored molecular Ge sources. Firstly, by varying the oxidation state of Ge in the precursors (left and centre images), the reduction potential required to deposit elemental Ge can be shifted to much less extreme voltages. The effect on the reduction potential of changing the halide ligands is also reported, as is the effect of altering the counterion of the Ge-containing precursor which influences the intramolecular interactions which are retained in the supercritical fluid solution. Finally, we have been able to deposit elemental Ge into micrometre-sized patterned substrates (right image), paving the way for the SCFED of Ge nanowires. References 1. J. Ke et al., Proc. Natl. Acad. Sci. U.S.A., 2009, 106, 14768–14772. The SCFED project (www.scfed.net) is a multidisciplinary collaboration of British universities investigating the fundamental and applied aspects of supercritical fluids 2. D. Cook et al., Phys. Chem. Chem. Phys., 2010, 12, 11744–11752 3. J. Ke et al., Phys. Chem. Chem. Phys., 2012, 14, 1517–1528

81

SL9D Variable temperature in situ synchrotron powder X-ray diffraction studies of CdS thin film growth from single source molecular precursors

Lauren Macreadie1,2, Helen Maynard-Casely3, Stuart Batten2, David Turner2 and Anthony Chesman1

1CSIRO Materials Science and Engineering, Bayview Avenue, Clayton, Victoria, 3168, Australia 2School of Chemistry, Monash Univeristy, Clayton 3800, Australia. 3Australian Synchrotron, 800 Blackburn Rd. Clayton, VIC, 3168, Australia

Email: [email protected] . The development of metal chalcogenide thin films for photovoltaic applications has been given much attention over the past decade in the search for clean and renewable energy resources. Cadmium sulphide thin films have been of particular interest as promising n-type semiconductor used in high efficiency CdTe, CIGS and CZTSSe solar cells.1 Thin films are generally developed vacuum based deposition methods, such as chemical vapour deposition (CVD), due to their ability to form dense films.2 However, these methods are expensive and energy intensive, thus creating a drive towards the development of solution based deposition routes, such as spray deposition and screen printing. Metal chalcogenide thin films are the primary goal of our research in order to produce flexible photovoltaic devices. We have developed soluble, air and moisture stable, cadmium ethylxanthate salts, (Me4N)[Cd(EtXn)3] and (Ph4P)[Cd(EtXn)3] for use as SSM precursors with pre-formed cadmium-sulfide bonds to form CdS thin films. Thermogravimetric analysis (TGA) confirmed the viability of these salts as SSM precursors for the development of thin films, with the potential for deposition on plastic substrates due to their low decomposition temperature ranges. In situ variable temperature PXRD studies, on both bulk material in capillaries and material deposited on glass substrates, were performed using the powder diffraction beamline at the Australian Synchrotron. The formation of the CdS hexagonal crystalline phase was observed upon the thermal decomposition of both precursors (Figure 1). These results gave us a significant insight into identifying the optimum annealing temperature of the metal complex salts to form the CdS thin films.

Figure 1: (left) Structure of (Me4N)[Cd(EtXn)3] with hydrogen atoms omitted for clarity; (right) In situ variable temperature PXRD data showing the growth of hexagonal CdS thin film deposited from (Me4N)[Cd(EtXn)3] precursor. References 1. M. A. Green, K. Emery, Y. Hishikawa, W. Warta, E. D. Dunlop, Prog. Photovoltaics Res. Appl. 2013, 21, 827. 2. R. M. Pasquarelli, D. S. Ginley, R. O'Hayre, Chem. Soc. Rev. 2011, 40, 5406.

82

SL7F Structured Inorganic Materials by Electrodeposition at Extreme Overpotential.

Lathe Jones, Daniel Oppedisano, Torsten John and Suresh Bhargava.

CAMIC – Centre for Advanced Materials and Industrial Chemistry, RMIT University, GPO Box 2476, Melbourne, Australia.

Email: [email protected] . The creation of high surface area inorganic materials can be achieved by a variety of methods, including the use of templates (soft or hard), reduction in solution by dissolved reducing agents, or by post treatments of metals such as anodisation or de-alloying.1

One of the most efficient methods used recently has been the use of high overpotentials, where hydrogen evolution can act as a dynamic template to create surfaces with a range of morphologies.

This talk will present some of our recent progress in this field,2 including preparation of a range of platinum surfaces, with both honeycomb and nanoforest morphologies, as well as ruthenium and ruthenium oxide sponge and foam type materials.

The materials formed can act as templates for a range of end uses, and we will present results for electrocatalysis of alcohols and surface capacitance.

Figure 1. Platinum nanoforest structures (left) and ruthenium sponge (right) prepared by electrodeposition.

References 1. Y. Liu, J. Goebl and Y. Yin, Chem. Soc. Rev., 2013, 42, 2610-2653 2. A. Ott, L. A. Jones and S.K. Bhargava, Electrochemistry Communications, 2011, 1248

83

SL7G Alkali metal hydride complexes: From monohydride species to well-defined nanometer-sized clusters

Andreas Stasch

School of Chemistry, Monash University, Clayton 3800, Victoria, Australia.

Email: [email protected]

The ionic or ‘saline’ s-block metal hydrides and their complexes are of importance as reagents in synthetic transformations such as hydride transfer and reductions, in catalysis, and for hydrogen storage applications.[1] Bulk alkali metal hydrides all show rock salt structures in the solid state having large lattice energies, are generally insoluble and, as a consequence, show a low reactivity towards many substrates. In recent years, a facile route into s-block metal hydride fragments has emerged that utilizes the metathesis between metal amide or alkyl-fragments and hydrides from simple silanes (silane route), see equation 1.

[M]-R (R = alkyl or amide, NR’2) + PhR’’SiH2 (R’’ = Ph, H) → [M]-H + PhR’’(R)SiH (1)

Despite this, well-defined alkali metal hydride complexes remain very rare. The large lattice energies combined with generally facile ligand exchange processes for group 1 metal cations can lead to their decomposition via elimination of the respective insoluble bulk metal hydride. We will present the synthesis, characterization and further chemistry of a series of ligand stabilized lithium hydride complexes with inorganic core of approximately 1 nm size. For example, we have recently synthesized a new sterically demanding phosphinoamide ligand and employed the silane route (1) to prepare the hydrocarbon- [2] soluble lithium complex shown in Figure 1, with a central (LiH)4 cube. The complex undergoes hydrolithiation reactions with activated substrates[2,3] though it has been found that the stabilizing phosphinoamide can form different competing addition products with those substrates.[3]

Fig. 1

Since then, we have extended this chemistry using different ligand classes and prepared larger lithium hydride cluster complexes that were characterized using synchrotron radiation.

References 1. See for a review: S. Harder, Chem. Commun. 2012, 48, 11165. 2. A. Stasch, Angew. Chem. Int. Ed. 2012, 51, 1930. 3. A. Stasch, submitted.

84

SL7H Towards the Synthesis of Efficient and Recyclable Catalysts

Chin Min Wong,1 Andrey A. Tregubov,1 Khuong Q. Vuong1 and Barbara A. Messerle1

1School of Chemistry, University of New South Wales, Sydney NSW 2052, Australia.

Email: [email protected], [email protected] . The immobilisation of organometallic catalysts onto solid supports leads to hybrid systems that combine the most interesting properties of homogeneous and heterogeneous catalysts.1 We have immobilized a series of Rh(I) complexes with bidentate N,N-donor ligands on glassy carbon (GC) electrodes (1-2, Figure 1) and carbon black XC-72R using strong C-C bonds to initially attach the ligands. The immobilised complexes are excellent catalysts for the hydroamination reaction of 4-pentyn-1-amine to 2-methyl-1-pyrroline. However, metal leaching from the immobilised ligand occurs over time and this has been attributed to the fact that the N,N-donor ligands do not bind with sufficient strength to the metal. In order to address the leaching problem, we are now using the above immobilization principle and incorporating stronger donors2 into the ligand design including triazoles, N-heterocyclic carbenes (NHC) and phosphines. The newly anchored ligands have been complexed with Rh(I) (eg. 3-6, Figure 1) and Ir(III), and these new immobilised complexes have been tested as catalysts for hydroamination3 and tandem C-N/C-C alkylation reactions.4

R N CO OC CO R CO CO OC N N N C CO Rh Rh Rh N Rh Rh PPh N CO CO 2 N N N N CO N N N N N N N N N N

GC GC GC GC GC 1 2 R = H, 3 5 6 R = CH , 4 3

Figure 1: Immobilised Rh(I) complexes (1-6) on glassy carbon electrodes (GC). We are also establishing a reliable approach for spontaneous immobilisation of the metal complexes directly onto the carbon surface using diazonium chemistry. This approach will allow us to expand the immobilisation of the homogeneous catalysts onto other porous carbon materials or on materials that do not conduct electrochemically (Scheme 1).

BPh4 Rh Rh L L' L L' NaNO2/HCl

CH3NO2

carbon NH2 surface L L' = bidentate N,N' or N-NHC or N,P ligands

Scheme 1: General route of the direct functionalisation of a Rh(I) complex. References 1. M. Perez-Cadenas, L. J. Lemus-Yegres, M. C. Roman-Martinez and C. Salinas-Martinez de Lecea, Appl. Catal., A, 2011, 402, 132. 2. (a) H. Struthers, T. L. Mindt and R. Schibli, Dalton Trans., 2010, 39, 675, (b) K. V. S. Ranganath, S. Onitsuka, A. K. Kumar and J. Inanaga, Catal. Sci. Technol., 2013, 3, 2161, (c) S. L. James, Chem. Soc. Rev., 2009, 38, 1744. 3. C. Hua, K. Q. Vuong, M. Bhadbhade and B. A. Messerle Organometallics, 2012, 31, 1790. 4. C. M. Wong, K. Q. Vuong, M. R. D. Gatus, C. Hua, M. Bhadbhade and B. A. Messerle, Organometallics, 2012, 31, 7500.

85

SL8F meso-Hydroxymetalloporphyrins and unusual paramagnetic nickel(II) porphyrinoids

Dennis P. Arnold, Farina Brackmann , Sarah J. Fletcher and Mean See Goh

School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, GPO Box 2434, Brisbane, 4001, Australia.

Email: [email protected] meso-Hydroxyporphyrins are known as intermediates in the biological degradation of heme,1 and their synthetic counterparts have properties that are unique on porphyrin coordination chemistry. It has been known for more than 30 years that meso-hydroxyoctaethylporphyrins such as the nickel(II) complex 1 readily form the oxy- radical 2,2 and also that they coordinate a fifth or sixth ligand (such as pyridine), which leads to unusual paramagnetic high-spin Ni(II) porphyrins.3

Our group has been working for many years on Pd-catalysed couplings of meso-halometalloporphyrins with carbon and nitrogen nucleophiles,4 and we now report the couplings with oxygen nucleophiles, including hydroxide itself. This presentation will cover the synthesis and spectra of a series of meso-hydroxydi- and triarylporphyrins 3, with a range of metals M. In particular, the EPR spectra of the oxy-radicals, and the nature of the species formed in the presence of pyridine and external oxidants will be described. This includes the novel dimer 4.

References 1. Balch, A. L. Coord. Chem Rev. 2000, 200-202, 349-377. 2. Balch, A. L.; Noll, B. C.; Phillips, S. L.; Reid, S. M.; Zovinka, E. P. Inorg. Chem. 1993, 32, 4730-4736. 3. Balch, A. L.; Olmstead, M. M.; Phillips, S. L. Inorg. Chem. 1993, 32, 3931-393. 4. See for example, Esdaile, L. J.; McMurtrie, J. C.; Turner, P.; Arnold, D. P. Tetrahedron Lett. 2005, 46, 6931; Esdaile, L. J.; Senge, M. O.; Arnold, D. P. Chem. Commun. 2006, 4192.

86

SL8G Homo- and Hetero-bimetallic Coinage Metal N-Heterocyclic Carbene Complexes

Peter J. Barnard, Thomas P. Pell, Brian W. Skelton and David J. D. Wilson

Department of Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, 3086, Australia. Centre for Microscopy, Characterization and Analysis, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009, Australia

Email: [email protected] . Attractive (aurophilic) interactions between closed shell Au(I) centres have been of great interest, both from experimental and theoretical points of view.1, 2 For linear two-coordinate Au(I) complexes, sub Van der Waals Au(I)⋅⋅⋅Au(I) contacts of less than 3.4 Å are commonly observed and these are often associated with intriguing photophysical properties, such as luminescence. Similar metallophilic interactions are sometimes observed for Cu and Ag and these systems also often display intense luminescence.3,4 Recently, the syntheses of heterobimetallic complexes that display metallophilic interactions between different coinage metals have been reported.5 We are interested in the synthesis of luminescent bimetallic coinage metal (Cu, Ag and Au) complexes where two closely spaced metal atoms are supported by bridging bidentate N-heterocyclic carbene (NHC) ligands. The excellent framework flexibility associated with NHC ligands allows for precise control over the distance between the metal atoms and in some cases for the luminescent properties of the resultant complexes to be ‘tuned’.6 Here, we report the results of a systematic study where a series of homobimetallic coinage metal complexes (Cu, Ag and Au) have been prepared from a bridging bidentate (pincer) NHC ligand. The resulting molecules allow the influence of the metal ion on complex properties to be evaluated. Further, a novel and versatile step-wise synthetic procedure has been developed in our lab for the preparation of heterobimetallic (Au-Ag and Au-Cu) complexes from the same bidentate ‘pincer’ NHC ligand. Theoretical (computational) studies for these new complexes have been conducted and these results will also be reported.

References 1. H. Schmidbaur, Gold Bull., 1990, 23, 11-21. 2. H. Schmidbaur, Chem. Soc. Rev., 1995, 24, 391-400. 3. W.-F. Fu, X. Gan, C.-M. Che, Q.-Y. Cao, Z.-Y. Zhou and N. N.-Y. Zhu, Chem. Eur. J., 2004, 10, 2228. 4. V. J. Catalano and M. A. Malwitz, Inorg. Chem., 2003, 42, 5483. 5. V. J. Catalano and A. O. Etogo, J. Organomet. Chem., 2005, 690, 6041. 6. P. J. Barnard, L. E. Wedlock, M. V. Baker, S. J. Berners-Price, D. A. Joyce, B. W. Skelton and J. H. Steer, Angew. Chem., Int. Ed., 2006, 45, 5966.

87

SL8H From the Electronics of Molecules to Molecular Electronics

Paul J. Low,a,b Santiago Marques-Gonzalez,b Josef B.G. Gluyas,b Matthias Parthey,c Martin Kaupp,c Richard J. Nichols,d S. Martine and P. Cea.e

a School of Chemistry and Biochemistry, University of Western Australia, Crawley, Perth, 6009 b Department of Chemistry, University of Durham, Durham, DH1 3LE, UK c Institut fur Chemie, Technische Universitat Berlin, Berlin, 10623, Berlin, Germany d Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, UK e Instituto de Ciencia de Materiales de Aragon, Universidad de Zaragoza, Zaragoza, 50009, Spain

Email: [email protected] . Molecular electronics is generally considered as a viable future technology base for the enhancement of existing silicon-based microelectronics.1 By incorporating electronically active molecular units into solid-state platforms, ‘hybrid’ systems with higher active component density, lower energy demand, lower cost and potentially new function compared with conventional devices may become possible. The rational development of molecular electronics is underpinned by an understanding of intramolecular electron transfer processes and molecular electronic structure, but is also critically dependent on the coupling of the molecule to (semi)conducting surfaces and interfaces, and the ability to fabricate these contacts into device structures.2

In this overview, the nature of some of these problems will be outlined, and some progress made in the authors’ laboratories described. Particular emphasis will be placed on: the role of redox-active organometallic molecules as components in molecular electronics;3 the determination of molecular electronic structure and interpretation of intervalence charge transfer spectra using combinations of (spectro)electrochemical and computational methods;4 the development of a novel molecule-surface contacting group;5 and the use of STM and electrochemical STM based platforms in the construction of nascent molecular electronic devices.

References 1. K. Moth-Poulsen, T. Bjornholm, Nature Nanotech. 2009, 4, 551. 2. S.J. Higgins, R. Nichols, S. Martin, P. Cea, H.S.J. van der Zant, M.M. Richter, P.J. Low, Organometallics 2011, 30, 7. 3. S. Marques-Gonzalez, D.S.Yufit, J.A.K. Howard, S. Martin, H.M. Osorio, V.M. Garcia-Suarez, R.J. Nichols, S.J. Higgins, P. Cea, P.J. Low, Dalton Trans. 2013, 42, 338. 4. M. Parthey, J.B.G. Gluyas, P.A. Schauer, D.S. Yufit, J.A.K. Howard, M. Kaupp, P.J. Low, Chem. Eur. J. 2013, 19, 9780. 5. G. Pera, S. Martin, L.M. Ballesteros, A.J. Hope, P.J. Low, R.J. Nichols, P. Cea, Chem. Eur. J. 2010, 16, 13398.

88

SL9F An Integrated Study of the Affinity for Cu(I) and Cu(II) of the Aβ Peptide and Domains of the Amyloid Precursor Protein: Implications for the Catalytic Production of Reactive Oxygen Species

Anthony G. Wedd, Tessa R. Young and Zhiguang Xiao

School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria 3010, Australia

Email: [email protected] . While the underlying molecular cause of Alzheimer’s disease remains unknown, mis-handling of the Aβ peptides derived from the amyloid precursor protein during recycling may be an initiating event ('the amyloid cascade'). Aberrant metal ion homeostasis appears to contribute by promoting aggregation of the peptides or inducing toxic gain of function. In this context, the potential role of the trace metal copper has been emphasized (see ref 1 for a review). Estimation of the affinities of the Aβ peptides for copper has a vexed history. The literature contains experimental values of the dissociation constants KD (eqn 1) for Cu(I) and Cu(II) in the respective ranges of 10-7-10-15 and 10-7-10-18 mol/L:- I II Cu- Aβ ⇔ Cu + Aβ KD (Cu = Cu or Cu ) (1)

This work reports an integrated study of the Aβ16 peptide employing new chromophoric probes for Cu(I) and Cu(II) (eg, see Figure).2,3 The Aβ16 peptide (DAEFRHDSGYEVHHQK) is a truncated form that provides the copper binding sites of highest affinity. The peptide is shown to exhibit significant affinities for copper in both oxidation states. This means that it can support redox catalysis. Its ability to catalyze a model reaction for the production of reactive oxygen species is explored. The work is extended to domains of the amyloid precursor protein (the source of the Aβ peptides).

Figure. Quenching of a new fluorescence probe for CuII that provides 200x improvement in sensitivity.

References 1. C. Hureau, Coord. Chem. Rev. 2012, 256, 2921. 2. Z. Xiao, L. Gottschlich, R. vd Meulen, S. R. Udagedara and A. G. Wedd, Metallomics 2013, 5, 501-13 3. T. R. Young, A. G. Wedd and Z. Xiao, submitted manuscript.

89

SL9G Ratiometric fluorescent tools to study oxidative stress.

Amandeep Kaur, Elizabeth.J.New

School of Chemistry, University of Sydney, Sydney 2006, Australia.

Email: [email protected]

The redox state of a biological cell is representative of the pro-oxidant – antioxidant equilibrium in the cell. Perturbations in this equilibrium in favour of pro-oxidant species (oxidative stress) have been shown to induce multitude of pathological conditions like, diabetes, obesity, cardiovascular and neurodegenerative diseases.1-3 Despite the established synergism between oxidative stress and disease, little is known about the extent of oxidative changes and the mechanisms involved. By far, the most popular approaches for studying oxidative stress have been quantification of single species that may be upstream effectors of oxidative stress, or the downstream effects.4 Development of simple chemical molecules that can report on cellular oxidative stress would enable us to decipher the mechanisms that lead to various diseases. We are developing new redox sensitive fluorescent tools that will assist in monitoring cellular redox state in real time via molecular imaging techniques. Our probes are based on biologically derived redox sensitive moieties that signal changes in cellular redox state by ratiometric changes in fluorescence, and are reversible. In particular, we have developed redox responsive sensors containing flavin tethered to other fluorophores (Figure 1). These probes give a ratiometric response to the redox state of their environment. These probes operate at biologically-relevant reduction potentials and pH. We intend to utilize these probes for cellular studies to understand the correlation between oxidative stress and disease. Furthermore, the results obtained would act as feedback to design additional analogues with modulated fluorescent responses, cell permeability and reduction potentials.

Figure 1: Schematic representation of the Flavin based redox probes

References 1. Finkel, T.; Holbrook, N. J., Nature 2000, 408 (6809), 239-247. 2. Sosa, V.; Moliné, T.; Somoza, R.; Paciucci, R.; Kondoh, H.; Lleonart, M. E., Ageing Research Reviews 2013, 12 (1), 376-390. 3. Liochev, S. I., Free Radical Biology and Medicine 2013, 60, 1-4. 4. Winterbourn, C. C., Biochimica et Biophysica Acta 2013.

90

SL9H Microwave Synthesis, DFT Calculations and Electron Transfer Studies of X [Ru(bpy)2(ppa )][PF6]2 Complexes

Phimphaka Harding, Jitnapa Sirirak and David James Harding

Molecular Technology Research Unit, School of Science, Walailak University, Thasala, Nakhon Si Thammarat 80161, Thailand.

Email: [email protected]

Rapid and efficient synthesis of Ru complexes is essential to realize their potential in dye sensitized solar cell technology. In this work the reaction of (4-X′-phenyl)-pyridin-2-ylmethylene-amine (ppaX) and cis- [Ru(bpy)2Cl2] in EtOH under microwave radiation for 10 minutes and subsequent anion exchange yields X 1 [Ru(bpy)2(ppa )][PF6]2 (X = Me 1, OMe 2, Cl 3 and Br 4) in high yields. H NMR spectra confirm the purity of the products and suggest that microwave synthesis is a powerful technique for the preparation of Ru complexes. UV-Vis spectra of 1-4 show very high intensity π-π* transitions in the UV region. The very broad band between 400-530 nm contains two overlapping bands with λmax ca. 425 and 480 nm. In addition, 3 and 4 show an extra band around 625 nm. Cyclic voltammetric studies of 1 – 4 show a reversible reduction process at -0.90, -0.89, - 0.80 and -0.79 V respectively and a reversible oxidation process at 1.53, 1.52, 1.52, 1.55 V respectively. DFT calculations reveal that the HOMO and LUMO for the four complexes are similar. The HOMO is a weakly 2 X antibonding combination of a Ru dz orbital and ppa based orbital, localized principally on the phenyl ring, X while the LUMO is constructed from Ru dxy and ppa π* orbitals, largely involving the pyridyl group.

Me Figure 1 HOMO and LUMO of [Ru(bpy)2(ppa )][PF6] 1

References 1. B. Bozic-Weber, E. C. Constable, C. E. Housecroft, M. Neuburger, J. R. Price, Dalton Trans., 2010, 39, 3585. 2. Y. Sun, M.l L. Machala, F. N. Castellano, Inorg. Chim. Acta, 2010, 363, 283.

91

SL10A Extended Architectures Derived from Cu(II) Complexes of 1,3-Aryl-Linked Bis-β- Diketonato Ligands: Towards a Pressure Controlled Molecular Switch

Leonard F. Lindoy

School of Chemistry F11, The University of Sydney, 2006, Australia.

Email: [email protected]

Rational design strategies have been used to construct neutral Cu(II) ‘platform’ complexes of type [Cu2(L)2], where L is the doubly deprotonated form of a 1,3-aryl linked bis-β-diketone of type [RC(=O)CH2C(=O)C6H4C(=O)CH2C(=O)R]. When reacted with mono- and potentially bridging difunctional amines both discrete as well as one-, two- and three-dimensional polymeric metal-organic species are known to be generated;1 new examples of this type, one showing a polycatenane topology, will be presented. The structures of two such products, [Cu2(L)2(N-methylmorpholine)2] and [Cu4(L)4(1-methylpiperazine)2]n (where for L, R = t-Bu in each case) have been investigated by X-ray diffraction at elevated pressures with the aid of a Diamond Anvil Cell. When pressure is applied to [Cu2(L)2(N-methylmorpholine)2] a reduction in void volume occurs, corresponding to a decrease in cell volume of 6.7% at 9.1 kbar. In contrast, when [{Cu2(L)2}2(1- methylpiperazine)4]n (R = t-Bu) was exposed to increasing pressure a reversible bond-breaking reaction takes place. The symmetry of the species increases and the complex is transformed into a new discrete species of type [Cu2(L)2(1-methylpiperazine)2]2 in which the 1-methylpiperazine co-ligand is bound to the copper centre via its tertiary amine. The relatively minor increase in pressure required to induce the significant reversible chemical and structural changes observed suggests that a species of this type could find application as a unique pressure- controlled switching device.

1 In a parallel synthetic study it was found that a monomeric product of the same [Cu2(L )2(mpip)2] stoichiometry (but as two mpip solvate) could be obtained directly when neat 1-methylpiperazine was used as the reaction solvent (rather than THF plus 1-methylpiperazine). However, surprisingly this product was the other isomer in which the secondary nitrogen of each 1-methylpiperazine unit was bound to a copper centre. The high pressure product appears likely to only exist in the crystalline state (when under pressure)!

Acknowledgements The author thanks the Australian Research Council for support and S. Parsons, P. A.Tasker and F. J. White from the Centre for Science at Extreme Conditions, University of Edinburgh, for assistance with the high pressure measurements. Reference 1. J. K. Clegg, M. J. Hayter, K. A. Jolliffe, L. F. Lindoy, J. C. McMurtrie, G. V. Meehan, S. M. Neville, S. Parsons, P. A. Tasker, P. Turner and F. J. White; Dalton Trans., 2010, 39, 2804.

92

SL10B Halogen Controlled Spin Crossover in [Fe(qsal-X)2]NCS Complexes

David J. Harding,a Wasinee Phonsri,a Phimphaka Harding,a Keith Murray,b Boujemaa Moubaraki,b and Harry Adamsc

aMolecular Technology Research Unit, School of Science, Walailak University, Thasala, Nakhon Si Thammarat, 80161, Thailand bDepartment of Chemistry, Monash University, Clayton, Victoria, 3800, Australia cDepartment of Chemistry, University of Sheffield, Sheffield, S3 7HF, UK

Email: [email protected]

Spin crossover materials continue to attract attention as a result of their many potential applications.1 In our continuing interest in Fe(III) spin crossover systems2,3 we have prepared a series of complexes based on halogen substituted quinolylsalicylaldimine ligands, [Fe(qsal-X)2]NCS (X = F, Cl, Br and I). This systematic study reveals that the spin crossover is tunable with the structure and magnetic behaviour strongly dependent on the size and nature of the halogen.

Figure 1 Structure of [Fe(qsal-F)2]NCS and χMT vs. T plot for [Fe(qsal-X)2]NCS (X = F, Cl and Br).

References 1. M. A. Halcrow, ed., Spin-Crossover Materials: Properties and Applications, John Wiley & Sons Ltd., Chichester, 2013. 2. D. J. Harding, W. Phonsri, P. Harding, I. A. Gass, K. S. Murray, B. Moubaraki, J. D. Cashion, L. Liu and S. G. Telfer, Chem. Commun., 2013, 49, 6340. 3. D. J. Harding, D. Sertphon, P. Harding, K. S. Murray, B. Moubaraki, J. D. Cashion and H. Adams, Chem. Eur. J., 2013, 19, 1082.

93

SL10C A new manganese MOF with open metal sites: quantitative post-synthetic metalation and X-ray crystal structures

Alexandre Burgun,1 Witold M. Bloch,1 Campbell Coghlan,1 Christopher J. Sumby1 and Christian J. Doonan1

School of Chemistry & Physics, University of Adelaide, Adelaide, SA 5005, Australia.

Email: [email protected]

Metal-Organic Frameworks (MOFs) containing open metal binding sites have lately been of great interest due to their potential to anchor a wide range of active catalysts by post-synthetic modifications [1]. Anchoring catalytic moieties within these materials is expected to yield more stable and reusable heterogeneous catalysts compared to their homogeneous catalytic parents, enabling size and shape-controlled catalysis [1,2]. However, post- synthetically modified MOFs with catalytically active metal centres are rare [3] and suffer from a lack of characterisation regarding the coordination sphere of the active species [4].

We have synthesised a unique porous 3D manganese MOF (MnMOF) replete with non-coordinated pyrazole donors capable of quantitative post-synthetic metal binding [5]. The metalation step occurs in a single-crystal to single-crystal (SC-SC) manner which facilitates unequivocal elucidation of the bound metal species (coordination sphere) by X-ray crystallography. As an example, active catalytic species (rhodium and palladium) have been site specifically grafted into the free metal binding sites of MnMOF. Subsequent reactions involving the fully metalated MnMOF have yielded catalytic intermediates which have been isolated and characterised. This new material provides insights into catalytic cycles and shows great potential for heterogeneous catalysis applications.

= Metal

SC-

MnMOF Metalated MnMOF

References 1. (a) S. M. Cohen, Chem. Rev., 2012, 112, 970. (b) K. K. Tanabe, S. M. Cohen, Chem. Soc. Rev., 2011, 40, 498. (c) L. Ma, C. Abney, W. Lin, Chem. Soc. Rev., 2009, 38, 1248. (d) D. Rankine, A. Avellaneda, M. R. Hill, C. J. Doonan, C. J. Sumby, Chem. Comm., 2012, 48, 10328. 2. D. T. Genna, A. G. Wong-Foy, A. J. Matzger, M. S. Sanford, J. Am. Chem. Soc., 2013, 135, 10586. 3. (a) L. Ma, J. M. Falkowski, C. Abney, W. Lin, Nat. Chem., 2010, 2, 838. (b) A. M. Shultz, A. A. Sarjeant, O. K. Farha, J. T. Hupp, S. T. Nguyen, J. Am. Chem. Soc., 2011, 133, 13252. (c) G-Q. Kong, X. Xu, C. Zou, C-D. Wu, Chem. Comm., 2011, 47, 11005. 4. (a) P. V. Dau, M. Kim, S. M. Cohen, Chem. Sci., 2013, 4, 601. (b) T. Jacobs, R. Clowes, A. I. Cooper, M. J. Hardie, Angew. Chem. Int. Ed., 2012, 51, 5192. 5. W. M. Bloch, A. Burgun, C. Coghlan, C. J. Doonan, C. J. Sumby, unpublished data.

94

SL11A 8- The [Ti16O24 (O2CPhMe-4)24] Ion – A Life-Like Titanoxane Nanomaterial

A. J. Nielson, and J. M. Waters

Chemistry, Institute of Natural and Mathematical Sciences, Massey University at Albany, Auckland, New Zealand

Abiogenesis is a process by which life forms arise from simple compounds accumulating in a primordial soup. This theory proposes that through further transformations, more complex entities – and ultimately life – developed in the soup. The most crucial challenge unanswered by this theory is how the relatively simple building blocks self-assemble to form more complex structures. During synthetic studies of various titanium complexes we have carried out crystallizations from p-tolualdehyde in the presence of air and moisture. In this medium, hydrolysis of one of the titanium complexes appears to have taken place resulting in the formation of Ti-O-Ti bonds. In addition, some p-tolualdehyde has been oxidized to p-toluic acid which in the anionic form 8- has become coordinated to the metal centers to give the [Ti16O24 (O2CPhMe-4)24] ion which has nanomaterial dimensions. The unique structure of this life-like nano-ion which has apparently resulted from self-assembly followed by crystallisation, will be discussed.

8- The [Ti16O24 (O2CPhMe-4)24] nano-ion

95

SL11B Electrosynthesis of Cobalt Oxide Water Oxidation Catalysts

Shannon Bonke, and Leone Spiccia

School of Chemistry, Monash University, Victoria 3800, Australia.

Email: [email protected], [email protected]

Renewable energy sources, such as solar radiation, are unable to usurp fossil fuels as the world’s primary energy source without the development of suitable energy conversion and storage systems.1 Energy storage through the production of a fuel, such as hydrogen, allows the use of solar energy, as desired in a transportable form. Hydrogen can be produced through electrolytic water splitting, which would ideally be powered by solar energy, but catalysis is required to increase the efficiency of this process. This is especially important for the + - energetically demanding and highly complex water oxidation step (2H2O → O2 + 4H + 4e ), and, to a lesser + - 2 extent, the hydrogen evolution step (2H + 2e → H2). 2+ A disordered phase of cobalt oxide (CoOx) prepared by oxidative electrodeposition of Co from buffered aqueous solutions has previously been shown to be an effective water oxidation catalyst.3 Building on this previous study, a series of cobalt complexes were examined as precursors for the deposition of CoOx with the aim of improving the activity of this water oxidation catalyst. It was found that cobalt(II)-aminocarboxylates, among others, can indeed be used for the electrodeposition of catalytically active cobalt oxide films. These 2+ precursor complexes were found to produce far thinner CoOx films than Co with a much higher relative activity per deposited Co atom. EXAFS indicated that the cobalt oxide phase was the same as that formed from Co2+,4 but the thinner films were much more transparent. In the future, integration of such transparent films with multi-junction semi-conductor photovoltaics or dye sensitized solar cells could allow the development of devices that split water using only solar radiation.

Caption: Cobalt complex to be electrodeposited as cobalt oxide onto a fluorine doped tin oxide (FTO) substrate (left). The cobalt oxide can be seen in the SEM image (right) as a thin film (white box) bridging two tin oxide crystals.

References 1. Lewis, N. S.; Nocera, D. G. Proc. Natl. Acad. Sci. U. S. A. 2006, 103, 15729. 2. Bard, A. J.; Fox, M. A. Accounts Chem. Res. 1995, 28, 141. 3. Kanan, M. W.; Nocera, D. G. Science 2008, 321, 1072. 4. Kanan, M. W.; Yano, J.; Surendranath, Y.; Dinca, M.; Yachandra, V. K.; Nocera, D. G. J. Am. Chem. Soc. 2010, 132, 13692.

96

SL11C Solution dynamics of large uranyl clusters

C. André Ohlin, Rene L. Johnson, Kristi Pellegrini, Peter C. Burns and William H. Casey

School of Chemistry, Monash University, Melbourne, Vic 3800, Australia

Email: [email protected]

Nuclear power has the potential to be both safe and clean, but only if the spent uranium fuel it generates can be properly processed and stored. In spite of more than half a century of use of uranium for these purposes, the solution chemistry of uranium is still poorly known which precludes us from understanding the full impact of potential spills or accidents.[1] For example, only a decade ago the existence of a large family of sphere-like uranyl oxo-peroxide structures -- anionic clusters made up by repeating units of uranyl-oxo and -peroxo units -- was unsuspected, yet these form quantitatively in a matter of seconds to minutes.[2]

48- In this study we have looked at the reaction dynamics of the peroxide cluster U24Py ([(UO2)24(O2)24(P2O7)12] ; see figure; [3]) by NMR methods, and the effects of pH and different counterions have been explored.

References 1. P. C. Burns, R. C. Ewing, A. Navrotsky Science, 2012, 335(6073), 1184-1188. 2. P. C. Burns Mineralogical Magazine, 2011, 75(1), 1-25. 3. J. Ling, J. Qiu, G. E. Sigmon, M. Ward, J. E. S. Szymanowski, P. C. Burns J. Am. Chem. Soc., 2010, 132(38), 13395-143402.

97

SL12A Catalytic Applications of Metallodendrimers

Selwyn Mapolie,

Department of Chemistry and Polymer Science, Stellenbosch University, Stellenbosch, 7601 South Africa.

Email: [email protected] . Metallodendrimers have in recent years emerged as a valuable alternative to conventional catalytic systems (homogeneous as well as heterogeneous)1. The application of metallodendrimers as catalyst precursors in a range of organic reactions has received increasing attention in the last couple of years 2-3. In this paper we highlight some of our work over the last few years where we have employed dendrimeric catalysts in the transformation of unsaturated hydrocarbons such as α-olefins, functionalized alkenes as well as alkynes. In addition several other organic transformations have been catalyzed by dendritic catalyst. Examples of dendritic catalysts developed in our group are shown in Figure 1.

Cl Cl Cl Pd N N Pd Cl N (OAc)2 N

N N N N N N N O N N O N Pd N Pd Cl N Cl 2+ Cl Ni Ni Ni Cl O O N N N N N N N N N Cl Pd N Pd Cl Cl N Cl N Cl Pd Cl Cl Pd Cl N N

Diaminobutane cored dendrimer Cyclam cored dendrimer

Figure 1: Examples of metallodendrimeric catalysts.

Several of the metallodendrimers developed by us have found use as catalysts in a range of different reactions. Thus for example Pd metallodendrimers have been employed as ethylene and phenyl acetylene polymerization catalysts. Some of the nickel systems have been effective as olefin oligomerization catalysts, outperforming it mononuclear analogues. Zn metallodendrimers have recently been found to active in ring opening polymerization of lactides showing high conversion of the monomer under relatively mild conditions. The main results from these reactions are highlighted in this paper.

References 1. D. Méry, D. Astruc, Coord. Chem. Rev. 2006, 250, 1965. 2. G. Smith, R. Chen, S. Mapolie, J. Organomet. Chem. 2003, 673, 111. 3. R. Andrés, E. de Jesus, F. J. de la Mata, J. C. Flores, R. Gomez, J. Organomet. Chem. 2005, 690, 939

98

SL12B Room temperature labelling of triaza-macrocyclic metal complexes with fluorine-18

Rajiv Bhalla,ab Christine Darby,c William Levason,c Sajinder K. Luthra,a Graeme McRobbie,a Gillian Reid,c George Sandersonc and Wenjian Zhangc

aGE Healthcare, White Lion Road, Amersham, HP7 9LL, UK bCentre for Advanced Imaging, University of Queensland, Brisbane, QLD 4072, Australia cSchool of Chemistry, University of Southampton, Southampton, SO17 1BJ, UK

Email: [email protected] . There has been an increasing focus in the application of “inorganic chemistry” to develop new strategies to introduce the fluorine-18 radioisotope into biomolecules.1 The increasing need to label peptides and macromolecules efficiently has meant there is a growing demand to develop simpler and faster methods for radiolabelling this class of compounds. Recently McBride and others have reported the use of Al–18F complexes based upon functionalised bis-carboxylate derivatives of 1,4,7-triazacyclononane for imaging a wide range of peptides rapidly in a single step. However, the need for elevated temperatures (100°C) for fluorination in this ‘one-pot’ approach places some limitations on its utility due to the thermal instability of some important high molecular weight biomolecules. In order to further extend the scope of this approach, an increased understanding of the chemistry and properties of fluoride complexes of the Group 13 elements is required. This presentation reports the development of triaza-macrocyclic complexes of aluminum, gallium and indium halides and reports their fast 18F and 19F incorporation via halide exchange at room temperature in aqueous solution.

Me Me

Cl F N N KF / 18F- R R N Ga Cl N Ga F oom Cl R 18F N Temperature N Me Me

References 1. G.E. Smith, H.L. Sladen, S.C.G. Biagini, P.J. Blower, Dalton Trans. 2011, 40, 6196. 2. W.J McBride, R.M. Sharkey and D.M. Goldenberg, EJNMMI Research 2013, 3:36.

99

SL12C Site-specific Bioconjugation of Copper-64 Chelators for PET Imaging

Brett M. Paterson,1,2 Karen Alt,3,4 Charmaine M. Jeffery,5 Roger I. Price,5,6 Jonathan M. White,1,2 Christoph E. Hagemeyer3 and Paul S. Donnelly1,2

1School of Chemistry and 2Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne 3010 Australia. 3Vascular Biotechnology Laboratory and 4Atherothrombosis and Vascular Laboratory, Baker IDI, Melbourne 3004 Australia. 5Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Nedlands, 6009 Australia. 6School of Physics, The University of Western Australia, Nedlands 6009 Australia

Email: [email protected]

The copper-64 radionuclide has the potential to be used for diagnostic imaging using positron emission tomography (PET), a molecular imaging technique that produces high-quality three-dimensional images of functional processes in the body for diagnosis and evaluation of responses to treatment. Biologically active molecules such as antibodies can be used to achieve targeted delivery of PET imaging agents. Current methods for applying antibodies as PET delivery systems typically result in non-specific conjugation and impairment or loss of antibody functionality. Enzyme mediated site-specific bioconjugation to antibodies is robust, highly reproducible and minimises the impact on antibody functionality.1 The use of copper radioisotopes for PET is possible using chelators such as the macrobicylic hexaamine cage ligands, termed sarcophagines (sar), which form extremely stable and kinetically inert CuII complexes for high target-to-background contrast.2 New sar- based bifunctional chelators based on [Cu(MeCOSar)](ClO4)2 (Fig 1), were designed, synthesised and site- specifically conjugated to an antibody. The antibody is specific for activated platelets in inflammatory diseases such as arthritis and atherosclerosis. The novel constructs were radiolabeled with copper-64 and evaluated in a mouse model of acute thrombosis using PET/CT (Fig 2).

Figure 1. A thermal ellipsoid plot (30% probability level) for [Cu(MeCOSar)](ClO4)2.

Figure 2. A small-animal PET/CT image of an in vivo model of mouse carotid artery thrombosis. References 1. H. T. Ta, K. Peter and C. E. Hagemeyer, Trends Cardiovasc. Med., 2012, 22, 105. 2. A. M. Sargeson, Coord. Chem. Rev., 1996, 151, 89.

100

Stranks 1

Redox Sulfur Chemistry in Copper Nutrition is Mediated by the Enzyme Grx1 Jens Brose, Zhiguang Xiao and Anthony G Wedd

School of Chemistry and Bio21 Institute, University of Melbourne, Parkville, VIC 3010

Email: [email protected]

Copper is an essential element for all living organisms since it is required as a catalytic cofactor for the functions of many redox enzymes.1,2 However, excess or free copper is toxic and must be strictly controlled. Regulation systems exist in biology for efficient control of copper binding and transport in living cells. Disorders in these systems are linked to various diseases such as Menkes-Wilson’s diseases, Alzheimer’s, Parkinson’s and mad cow diseases. Proteins that regulate copper predominantly employ two cysteine thiolate ligands in a CxxC motif to form a linear two-coordinate complex with Cu(I). However, this dithiol unit is subject to oxidation to form an intramolecular disulfide bond that has little affinity for Cu(I). Consequently, reversible and fast inter-conversion between the reduced dithiol and oxidized disulfide forms is crucial for copper nutrition. This inter-conversion is promoted by the tripeptide glutathione (γ-Glu-Cys-Gly; GSH), the cellular redox buffer that also employs a disulfide/thiol couple GSSG/GSH. This work reports that a key enzyme involved in catalyzing this process in human cells is glutaredoxin 1 (Grx1).3,4 Intriguingly, Grx1 employs a similar CxxC motif as the active center for its catalytic function. It is demonstrated that: (i) the CxxC active site in Grx1 can also bind Cu(I) with high affinity at the femtomolar level and that Cu(I)-binding modulates its redox activity; (ii) the sulfur redox chemistry of the CxxC motif in the crucial copper transport protein Atox1 is controlled thermodynamically by Cu(I) binding and is catalyzed by Grx1. The work details the connection between the copper transport protein Atox1, the redox enzyme Grx1 and the cellular redox buffer GSH. The relevance of these findings to copper nutrition will be discussed.

References 1. Singleton, C. L. B., N.E. Dalton Transactions 2008, 688. 2. Kim, B. E.; Nevitt, T.; Thiele, D. J. Nat Chem Biol 2008, 4, 176. 3. Fernandes, A. P.; Holmgren, A. Antioxid Redox Signal 2004, 6, 63. 4. Yu, J.; Zhang, N. N.; Yin, P. D.; Cui, P. X.; Zhou, C. Z. Proteins 2008, 72, 1077.

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Stranks 2

Unique rod-like lanthanide clusters supported by a new class of tetrazolyl functionalised calixarenes

D. D’Alessio1, B. Skelton2, A. Sobolev2, N. A. Lengkeek3, A. M. Krause-Heuer3, I. Greguric3, B. H. Fraser3, M. Massi1 and M. I. Ogden1

1Department of Chemistry, Curtin University, Bentley, WA, 6102 2CMCA, University of Western Australia, Crawley, WA, 6009 3ANSTO, LifeSciences Division, Kirrawee DC, NSW, 2232

Email: [email protected]

Calixarene derivatives have been used extensively as ligands for the coordination of a range of metal ions1. The synthesis of a new library of calixarene ligands bearing tetrazole functionalities on the lower rim extends this range of calixarene-based ionophores2. Our investigation into the coordination chemistry of this system with lanthanide ions has revealed the formation of unique structural motifs, ranging from typical mononuclear host-guest complexes to unprecedented rod-like clusters. The key to this extraordinary behavior is the tetrazolato moiety, which supports these structures through its bridging capabilities. Characterisation by single crystal X-ray diffraction reveals that both the number of tetrazole rings present in the calixarene and the specific lanthanide ion dictate the final structure of the complex.

Bis-, tris, and tetra-tetrazolyl calix[4]arenes have been synthesized and found to have significant variation in behavior as ionophores. Here we report the synthesis of the three tetrazolyl-calix[4]arenes and their complexation chemistry with a range of lanthanide ions. The photophysical properties of these species will be discussed, along with the corresponding structural data.

References 1. Gutsche, D (2008). Calixarenes: An Introduction. 2nd ed. Cambridge, UK: The Royal Society of Chemistry. 164-207. 2. D’Alessio, D.; Muzzioli, S.; Skelton, B.; Stagni, S.;Massi, M.; Ogden, M. Dalton Trans., 2012, 41, 4736

102

Stranks 3

Ligand Steric Bulk as a Deactivation Trigger for N-Heterocyclic Carbene Catalysts

Curtis C. Ho, Michael G. Gardiner, Peter D.W. Boyd, Agustí Lledós and Catriona R. Vanston

School of Chemistry, University of Tasmania, Private Bag 75, Hobart TAS 7001, Australia.

Email: [email protected] . We previously reported5 the formation of a novel dipalladium(I) hydride species [{μ-(MesIm)2CH2}2Pd2H][PF6] stabilised by a bulky bridging bis(NHC) ligand. The complex was accessed under catalytically relevant conditions by base-assisted reduction (Na2CO3/MeOH) of the chelating bis(NHC) palladium(II) precursor, [{(MesIm)2CH2}Pd(NCMe)2][PF6]2, Scheme 1. A sterically more congested analogue has now been obtained that represents the first example of a dipalladium(I) complex without a Pd-Pd bond.

Scheme 1 We will report on our synthetic and computational mechanistic study of the formation of these dipalladium(I) hydride complexes and discuss how this relates to the understanding of reductive catalyst deactivation routes and/or the formation of Pd(I) species under catalytically relevant conditions that are typically considered to follow Pd(0)/Pd(II) catalytic cycles. A number of structural transformations are apparent in the overall reaction processes leading to the formation of the dipalladium(I) hydride complexes; namely; i, mononuclear to dinuclear, ii, bis(NHC) chelating to bridging, iii, palladium reduction and, iv, hydride formation. Comparative analysis of a range of isolated reactive intermediates, coupled with DFT computational studies aided in identifying many mechanistic steps. Of key importance is the steric congestion in a series of dimeric Pd(II)OMe complexes as early stage intermediates that were identified to feature variously contorted isomeric structures. These dimers are disfavoured relative to the mononuclear complexes for the bulkier systems, which react via β-hydrogen elimination giving Pd(II) hydride complexes leading to the observed final Pd(I) products, Scheme 2.

R R 2+ R + N N N Me O O N N N Pd Pd no Pd CH reaction 2 N N N O H Me N N N R R R Scheme 2 Later stage intermediates have proven to be elusive, but DFT studies have provided a plausible pathway through the sequence of dimerisation, reduction (MeO- assisted removal of H- ligand as H+) and hydride ligand fluxional processes. More recently we are have broadened our mechanistic studies to include a series of analogues targeting N,Nˈ- asymmetrically substituted variants[2] and longer alkylene bridges in the bis(NHC) ligands. The latter extension has resulted in the discovery of an unusual ligand rearrangement arising from a novel carbene complex decomposition route. References P.D.W. Boyd, A.J. Edwards, M.G. Gardiner, C.C. Ho, M.-H. Lemée-Cailleau, D.S. McGuinness, A. Riapanitra, J.W. Steed, D.N. Stringer, B.F. Yates, Angew. Chem. Int. Ed. 2010, 49, 6315. M.G. Gardiner, C.C. Ho, F.M. Mackay, D.S. McGuinness, M. Tucker, Dalton Trans. 2013, 42, 7447.

103

Stranks 4

Exploring Multifunctionality in Redox-Active Coordination Polymers

Chanel F. Leong and Deanna M. D'Alessandro

School of Chemistry, University of Sydney, Sydney 2006, Australia.

Email:[email protected]

Research into multidimensional coordination polymers has been rapidly expanding over the last decade due to their promise in energy efficient gas separation, catalysis and sensing. Of particular interest is the design of redox-active metal-organic frameworks (MOFs), which exhibit interesting electronic and optical properties potentially capable of selective gas separation, guest dependent signal transduction, and/or semiconductor-like behaviour. In this presentation, we report the structural incorporation of the redox-active moieties, naphthalene diimide (NDI), tetrathiafulvalene (TTF) and ferrocene (Fc) into coordination polymers to produce electronically dynamic systems, in particular, donor-acceptor systems. We study the enhancement of selective CO2 adsorption of an NDI-based framework, Zn(NDC)(DPMBI)1 where NDC = 2,6-naphthalenedicarboxylate and DPMBI = N,N'-di-(4-pyridylmethyl)- 1,2,4,5-benzenetetracarboxydiimide, via chemical reduction of its redox-active ligand backbone. Upon chemical reduction, the radical anion state of Zn(NDC)(DPMBI) exhibits enhanced CO2/N2 selectivity, which is attributed to the improved electrostatic host-guest interactions. Furthermore, we investigate the relationship between the spatial organisation of redox-active cores, i.e. the extent of π-π* stacking interactions in coordination polymers, and their effects on bulk properties such as photoluminescence and conductivity. We explore the electrochemical and optical properties of the coordination 2 polymers, (Zn(DMF)NO3)2(NDC)(DPMNI), (Zn(DMF))2(TTFTC)(DPNI) and Zn(FcDC)(DPNI) where DMF = N,N'- dimethylformamide, DPMNI = N,N'-di-(4-pyridylmethyl)-1,2,4,5-naphthalenetetracarboxydiimide, TTFTC = tetrathiafulvalenetetracarboxylate, DPNI = N,N'-di-(4-pyridyl)-1,2,4,5-naphthalenetetracarboxydiimide and FcDC = 1,1'-ferrocenedicarboxylate, to shed light on their potential as sensory and/or semiconducting materials. A host of techniques have been employed, including single crystal and powder X-ray diffraction, electron paramagnetic resonance, gas sorption, solid-state electrochemistry, solid-state spectroelectrochemistry,3 UV-Vis-NIR spectroscopy and confocal fluorescence microscopy.

Figure 1: Structure of Zn(NDC)(DPMBI), its solid-state redox properties and improved CO2 uptake upon chemical reduction.

References 1. Leong, C. F.; Faust, T. B.; Turner, P.; Usov, P. M.; Kepert, C. J.; Babarao, R.; Thornton, A. W.; D'Alessandro, D. M. Dalton Transactions 2013, 42 (27), 9831-9839. 2. Leong, C. F.; Chan, B.; Faust, T. B.; Turner, P.; Radom, L.; D’Alessandro, D. M. 2013, In submission. 3. Usov, P. M.; Fabian, C.; D'Alessandro, D. M. Chemical Communications 2012, 48 (33), 3945-3947.

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Stranks 5

Development of Functionalised Pd2L4 Metallosupramolecular Cisplatin Drug Delivery Vectors

James E. M. Lewis, Katrin Knerr, Anja Robert, Anastasia B. S. Elliott, C. John McAdam, Keith C. Gordon, Greg I. Giles and James D. Crowley

Department of Chemistry, University of Otago, Dunedin 9016, New Zealand.

Email: [email protected]

Cisplatin has been regarded as one of the most successful anticancer agents since its approval for chemotherapeutic treatment in the 1970s. However, as with all chemotherapeutics, cisplatin treatment is associated with a number of undesirable side effects, the result of general toxicity that also limits the administrable dose.1 Two main approaches to circumvent these issues are the development of novel therapeutics, and the use of macromolecular drug delivery vectors to target existing drugs to tumours.2 We have been interested in developing drug delivery vectors through the use of metallosupramolecular chemistry, which offers several advantages over alternative vectors, including high-yielding self-assembly, and facile synthetic modification. We have previously reported the self-assembly of an endohedrally 3 functionalised Pd2L4 architecture capable of encapsulating two molecules of cisplatin. Subsequently we have developed a methodology for appending a wide range of exohedral functional moieties through CuAAC ‘click’ chemistry (Figure 1).4 We have expanded this to include the incorporation of stable inorganic groups, including II I Ru (N∩N)(2,2’-bpy)2 and Re (N∩N)(CO)3Cl, of interest for their emissive properties. Furthermore, some of these metallosupramolecular assemblies we have been investigating are showing promise as novel cytotoxic agents. Our most recent results towards the development of these functionalised systems, as well as an examination of their cytotoxicity, will be presented.

Figure 1. CuAAC ‘click’ chemistry can be used to append a wide variety of functional moieties to the external face of this tripyridyl ligand framework, without affecting self-assembly of the desired Pd2L4 architectures.

References

P. J. Loehrer and L. H. Einhorn, Ann. Intern. Med., 1984, 100, 704-713. B. W. Harper, A. M. Krause-Heuer, M. P. Grant, M. Manohar, K. B. Garbutcheon-Singh and J. R. Aldrich-Wright, Chem. Eur. J., 2010, 16, 7064-7077. J. E. M. Lewis, E. L. Gavey, S. A. Cameron and J. D. Crowley, Chem. Sci., 2012, 3, 778-784. J. E. M. Lewis, C. J. McAdam, M. G. Gardiner and J. D. Crowley, Chem. Commun., 2013, 49, 3398-3400.

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Stranks 6

The fate of selenium supplements in biological systems: XAS and XFM studies Claire M. Weekley,* Paul K. Witting^ and Hugh H. Harris*

*School of Chemistry and Physics, The University of Adelaide, Adelaide 5005, Australia. ^Discipline of Pathology, The University of Sydney, Sydney 2006, Australia

Email: [email protected] . Selenium has been studied intensively in recent years for its anticancer properties. Inconclusive results from clinical trials into the prevention of cancer by selenium supplementation contradict the results of laboratory experiments where selenium exhibits anticancer activity in vitro and in vivo. A potential factor in the disconnect between the results of clinical trials and laboratory experiments is the choice of selenium supplement.1 The anticancer mechanisms of selenium compounds are exerted by their metabolites, yet research into the connection between the chemical form of selenium, its metabolism and its biological activity has been limited.

We have applied synchrotron-based X-ray techniques to the study of selenium speciation and distribution in cells and in vivo.2

X-ray absorption spectroscopy (XAS) studies, in combination with X-ray fluorescence microscopy (XFM) have revealed the variation in Se speciation and distribution in cancer cells treated with selenomethionine, methylselenocysteine or selenite.3-5 The differing toxicities of these selenium compounds to cancer cells is linked to their distinctly different speciation in cells.

XFM studies into the distribution of the metabolites of selenite in cells and in vivo have revealed a spatial association between Se and Cu. Preliminary research into this association suggest that its origins are different in cancer cells and in rat tissues. Further work is required to understand this tantalising link between Se and Cu, but its discovery demonstrates the important contributions that synchrotron-based techniques can make to the investigation of elemental speciation and distribution in biological systems.

XFM elemental maps showing Se and Cu colocalisation in a selenite-treated cancer cell.

References 1. C. M. Weekley and H. H. Harris, Chem. Soc. Rev. 2013, doi:10.1021/bi201462u. 2. C. M. Weekley et al., Nutrients 2013, 5, 1734-56. 3. C. M. Weekley et al., Biochemistry 2011, 50, 1641-50. 4. C. M. Weekley et al., Biochemistry 2012, 51, 736-738. 5. C. M. Weekley et al., JACS 2011, 133, 18272-9.

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