Universi^ M Iom Lm S

Total Page:16

File Type:pdf, Size:1020Kb

Universi^ M Iom Lm S INFORMATION TO USERS This reproduction was made from a copy of a document sent to us for microfilming. While the most advanced technology has been used to photograph and reproduce this document, the quality of the reproduction is heavily dependent upon the quality of the material submitted. The following explanation of techniques is provided to help clarify markings or notations which may appear on this reproduction. 1.The sign or “target” for pages apparently lacking from the document photographed is “Missing Page(s)”. If it was possible to obtain the missing page(s) or section, they are spliced into the film along with adjacent pages. This may have necessitated cutting through an image and duplicating adjacent pages to assure complete continuity. 2. When an image on the film is obliterated with a round black mark, it is an indication of either blurred copy because of movement during exposure, duplicate copy, or copyrighted materials that should not have been filmed. For blurred pages, a good image of the page can be found in the adjacent frame. If copyrighted materials were deleted, a target note will appear listing the pages in the adjacent frame. 3. When a map, drawing or chart, etc., is part of the material being photographed, a definite method of “sectioning” the material has been followed. It is customary to begin filming at the upper left hand corner of a large sheet and to continue from left to right in equal sections with small overlaps. If necessary, sectioning is continued again-beginning below the first row and continuing on until complete. 4. For illustrations that cannot be satisfactorily reproduced by xerographic means, photographic prints can be purchased at additional cost and inserted into your xerographic copy. These prints are available upon request from the Dissertations Customer Services Department. 5. Some pages in any document may have indistinct print. In all cases the best available copy has been filmed. U niversi^ M io m lm s International 300 N. Zeeb Road Ann Arbor, Ml 48106 8305306 Caste, Maureen Lynch TRANSITION METAL COMPLEXES OF POLYMER SUPPORTED MACROCYCLIC LIGANDS The Ohio State University Ph.D. 1982 University Microfilms I ntern atio n si 300 N. Zeeb Road, Ann Arbor, MI 48106 PLEASE NOTE: In all cases this material has been filmed in the best possible way from the available copy. Problems encountered with this document have been identified here with a check mark V 1. Glossy photographs or pages. 2. Colored illustrations, paper or print _____ 3. Photographs with dark background _____ 4. Illustrations are poor copy ______ 5. Pages with black marks, not original copy. 6. Print shows through as there is text on both sides of page. 7. Indistinct, broken or small print on several p ag es. 8. Print exceeds margin requirements _____ 9. Tightiy bound copy with print lost in spine ______ 10. Computer printout pages with indistinct print. 11. Page(s) lacking when material received, and not available from school or author. 12. Page(s)___________ ..seem to be missing in numbering only as text follows. 13. Two pages n u mbered ___________ . Text fol lows. 14. Curling and wrinkled pages ______ 15. Other ______________________________________________________________ University Microfilms International TRANSITION METAL COMPLEXES OF POLYMER SUPPORTED MACROCYCLIC LIGANDS DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Maureen Lynch Caste, B.S., M.S. ***** The Ohio State University 1982 Reading Committee: Professor Daryle H. Busch Professor Devon W. Meek Professor Bruce E. Bursten Approved by: Advisor Department of Chemistry To my Korn and Dad ii ACKNOWLEDGMENTS My sincere thanks are extended to all members of Dr. Busch's research group, past and present, whose assistance and encouragement aided in the accomplishment of this work. Dr. Jeffrey Church and Dr. Judy Gallucci are specially noted for the solution of the crystal structure presented in this thesis and are thanked accordingly. As a long time friend and associate, I thank Dr. Randall J. Remmel who has been an Inspiration to me through his continuing encouragement and interest in my chemical career since I began my undergraduate degree. To end on a personal note, I would like to express the appreciation that I feel toward Mr. Jeffery C. Bricker for his deep insight in the area of chemistry, his encouragement of my pursuits, and his special friendship. But, above all, the most especial thanks are given to Dr. Daryle H. Busch for his support, both financial and emotional, his •j guidance in this work, and his friendship over the past three years. ill VITA November 30, 1954................ Born, Brooklyn, New York August, 1978 .................... B.S., University of Alabama in Birmingham Sept. 1978 - Dec. 1979 ......... Teaching Assistant, Department of Chemistry, The Ohio State Univ. Jan. 1980 - Oct. 1981 .... Research Associate, Department of Chemistry, The Ohio State Univ. October 1981 .................... M.S., The Ohio State University Columbus, Ohio Nov. 1981 - Sept. 1982 ......... Research Associate, Department of Chemistry, The Ohio State Univ. PUBLICATIONS Maureen Lynch Caste and Daryle H. Busch, ''Transition Metal Complexes of Polymer Supported Macrocyclic Ligands — Oxygen Binding and Oxygenation of Organic Substrates,'' 14th ACS Central Regional Meeting, Midland, Michigan, June 1982, Abstract 120. Sheldon G. Shore, Wen-Liang Hsu, Clemens R. Weisenberger, Maureen Lynch Caste, Melvyn Rowen Churchill, and Clifford Bueno, ''New Syntheses of Mixed Metal Clusters from HgOsa(CO)lo. Crystal and Molecular Structure of the Paramagnetic Cluster H 3 (n'-C5H 5 )CoOsa(CO), and Its Diamagnetic Structural Analogue H 3 (ri®-CsHs)Ni0 s3 (C0 ) 9 , " Organometalllcs. 1982, 1, 1405. FIELD OF STUDY Major Field: Chemistry Specialization — Inorganic Coordination Chemistry, Professor Daryle H. Busch, Advisor iv TABLE OF CONTENTS Page DEDICATION .......................................................... ii A C K N O W L E D G M E N T S .................................................... iii VITA ................................................................. iv LIST OF T A B L E S ........................................... vii LIST OF F I G U R E S ................................................... viii Chapter I. INTRODUCTION ............................................. 1 Polymer Supported Metals and Métal Complexes 1 Heme Protein Modeling 3 Polymer Supported Catalysts 17 Hydrogenations and Hydroformylations using Supported Catalysts 23 Selected Oxidation Reactions Using Supported Polymers 27 Complexes of Lacunar Ligands 43 Statement of the Problem 50 II. E X P E R I M E N T A L ............................................... 52 General Procedures 52 Physical Measurement 52 Synthesis of Nickel Complexes 54 Preparation of Ligand Salts 59 Synthesis of Cobalt Complexes 60 Preparation of the Supported Complexes 62 Adsorption of Cobalt(II) Complexes on Polymeric 6 8 Oxygen Exposure to the Polymer Samples 70 Polymer Reactions with Oxygen and Organic Substrates 71 V CONTENTS (CONT'D) III. CRYSTAL STRUCTURE AND PROPERTIES OF A NOVEL COBALT(II) COMPOUND CONTAINING FIVE COORDINATED NITROGENS, [Co{ (MeNIMINOETHYL) (MeNHETHYLDMea [l6]TETRAENENs }] (PFg) 2 73 Chemical Evidence for Pentadentate Chelation to the Cobalt(II) Species 77 Crystal Structure 85 Reaction of the Cobalt(II) Complex with Oxygen 97 IV. RESULTS AND D I S C U S S I O N .................................. 109 Model Studies 109 Chloromethylated Polystyrene 109 Poly(Vinylpyridine) 120 Controlled Pore Glass 122 Attachment of the Polymeric Supports 127 Covalent Attachment 127 Coordination Attachment 145 CFG Support 147 Reactions of the Polymer Supported Cobalt Complexes with Oxygen 152 Covalently Attached Complexes 152 Coordinately Attached Complexes 158 CPG Support 164 Reactions of Polymer Supported Complexes 166 Oxidation Catalysis 166 Gas Chromatographic Supports 171 APPENDIX A ........................................................ 178 APPENDIX B ..................................................... • 194 FOOTNOTES ........................................................ VI LIST OF TABLES Page Table 1. Materials Used to Support Metal Complexes ......... 2 2. NMR Peak Shifts for ICo{(MeN Iminoethyl)(MeN Ethi)Me2[16]-tetraene Ns}](PFe )2 in C D 3ON ......... 3. Summary of Crystallographic Data for C0 C 2 2 N 7H 3 2 P 2F 12 89 4. Bond Distances (A) and Angles (Deg)(B) with their Estimated Standard Deviations for C 0 C 2 2N 7H 3 2 P 3F 22 94 5. ‘h NMR Peak Shift for tCo{ (MeNIminoethyl)(MeNEthi)- M e 2 Ï16]tetraene N 5}](PF«) 2 , After Exposure to Oxygen, CDsCN Solvent, Room Temperature .................... 99 6 . NÈR Peak Shifts for ICo{MeNIminoethyl)(MeNEthi)- M e 2 [16]tetraene N-JlCPF*): After Exposure to Oxygen, CDaCN.Solvent ........................................ 99 7. NMR Assignments for [Ni{(NBz)2 (CHa)eMea[16]tetraene N 4 }](PFe) 2 in CDaCN, 80 MHz, 4 0 ° C ............... 118 8 . ^^C NMR Assignments for [Ni{(BzNMe)aMea[16]tetraene n J ] ( P F 6 > 2 in CDaCN, 8 MHz, 4 0 ° C .................. 120 9. Complexes Which have been Covalently Attached to Chloromethylated Polystyrene......................... 131 10. Analysis of Cobalt Complexes Covalently Attached to Chloromethylated Polystyrene ...................... 132 11. Lacunar Complexes which are Coordinatively Attached to Polymer Through Interaction with Pyridine Function 146 vii LIST OP FIGURES Figure Page 1. Methods of Attaching Complexes
Recommended publications
  • Α,Ω-Biphenylpolyynes)
    1 ONE-POT SYNTHESIS AND CHARACTERIZATION OF POLYYNES END-CAPPED BY BIPHENYL GROUPS (α,ω-BIPHENYLPOLYYNES) Franco Cataldo1(*), Ornella Ursini2, Alberto Milani3 , Carlo S. Casari3 1Actinium Chemical Research Institute, Via Casilina 1626 A, Rome, Italy 2CNR - Istituto di Metodologie Chimiche, Montelibretti, Roma 3 Department of Energy, Politecnico di Milano via Ponzio 34/3, I-20133 Milano, Italy Abstract Stable polyyne chains terminated with biphenyl end groups (α,ω-biphenylpolyynes) were synthesized in a single step with an easy procedure by using the Cadiot-Chodkiewicz reaction conditions. The α,ω-biphenylpolyynes were separated through HPLC analysis and identified by means of their electronic absorption spectra. The α,ω-biphenylpolyynes were studied by FT-IR and Raman spectroscopy and the spectral interpretation was supported with DFT calculations. A peculiar stability of α,ω-biphenylpolyynes towards ozone was also observed. 1. Introduction The sensational report about the production of a long polyyne chain of 6000 carbon atoms enclosed in a double wall carbon nanotube (DWCNT) [1] has re-awakened the enthusiasm about carbyne, the fabulous carbon allotrope made by an infinitely long sequence of carbon atoms with sp hybridization (with either alternated single and triple bonds or cumulated double bonds). Earlier attempts to the synthesis of carbyne are reviewed for example in the book of Heimann at al. [2]. *Corresponding author. Tel: 0039-06-94368230. E-mail: [email protected] The chemical approach toward the synthesis of this long acetylenic structure for example through the Glaser coupling reaction invariably led to a crosslinked carbonaceous solid [3,4] whose solid state 13C-NMR analysis and Raman spectroscopy revealed indeed the presence of sp hybridized carbon 2 atoms but mixed with sp2 and sp3 hybridized carbon atoms due to undesired crosslinking reactions [5,6].
    [Show full text]
  • Implications for Extraterrestrial Hydrocarbon Chemistry: Analysis Of
    The Astrophysical Journal, 889:3 (26pp), 2020 January 20 https://doi.org/10.3847/1538-4357/ab616c © 2020. The American Astronomical Society. All rights reserved. Implications for Extraterrestrial Hydrocarbon Chemistry: Analysis of Acetylene (C2H2) and D2-acetylene (C2D2) Ices Exposed to Ionizing Radiation via Ultraviolet–Visible Spectroscopy, Infrared Spectroscopy, and Reflectron Time-of-flight Mass Spectrometry Matthew J. Abplanalp1,2 and Ralf I. Kaiser1,2 1 W. M. Keck Research Laboratory in Astrochemistry, University of Hawaii at Manoa, Honolulu, HI 96822, USA 2 Department of Chemistry, University of Hawaii at Manoa, Honolulu, HI 96822, USA Received 2019 October 4; revised 2019 December 7; accepted 2019 December 10; published 2020 January 20 Abstract The processing of the simple hydrocarbon ice, acetylene (C2H2/C2D2), via energetic electrons, thus simulating the processes in the track of galactic cosmic-ray particles penetrating solid matter, was carried out in an ultrahigh vacuum surface apparatus. The chemical evolution of the ices was monitored online and in situ utilizing Fourier transform infrared spectroscopy (FTIR) and ultraviolet–visible spectroscopy and, during temperature programmed desorption, via a quadrupole mass spectrometer with an electron impact ionization source (EI-QMS) and a reflectron time-of-flight mass spectrometer utilizing single-photon photoionization (SPI-ReTOF-MS) along with resonance-enhanced multiphoton photoionization (REMPI-ReTOF-MS). The confirmation of previous in situ studies of ethylene ice irradiation
    [Show full text]
  • A Post-Buckminsterfullerene View of Carbon Chemistry
    A POST-BUCKMINSTERFULLERENE VIEW OF CARBON CHEMISTRY Harold Kroto School of Chemistry and Molecular Sciences, University of Sussex, Brighton, BNI 9QJ UK Keywords: Cs0, Fullerenes, carbon particles INTRODUCTION The discovery of c60 Buckminsterfullerene, Fig 1, has its origins in a research programme involving synthetic chemistry, microwave spectroscopy and radioastronomyl. In 1915, at Sussex (with David Walton), the long chain polyyne H-CeC-CsC-CsN was synthesised and studied by microwave spectroscopy. Subsequently, with Takeshi Oka and NRC(0ttawa) astronomers, the molecule was discovered in space, Fig 2, by radioastronomy using the laboratory microwave frequencies. This discovery led on to the detection of the even longer carbon chain molecules HCTN, HCgN and HCl.lN in the space between the stars2. Further work aimed at understanding the formation of the chains in space focussed attention on the possibility that they are produced at the same time as carbon dust in red giant stars1,*. During experiments at Rice University in 1985 (with James Heath, Sean O'Brien, Robert Curl and Richard Smalley), designed to simulate the conditions in these stars and explore their capacity for carbon chain formation, the exciting discovery that C60 was remarkably stable was made3. It was found that under conditions where almost all the atoms in a carbon plasma had nucleated to form microparticles the molecule c60 remained behind - together with some CTO. This result was, as is now well 'known, rationalised on the basis of the closed cage structure shown in Fig 1. It was proposed that the geodesic and aromatic factors inherent in such a structure could account for the stability of the molecule.
    [Show full text]
  • Pdf 372.94 Kb
    The Development of Molecular Wires PART 11: ROLE OF RUTHENIUM AND OSMIUM POLYPYRIDINE COMPLEXES FOR FAST VECTORIAL ELECTRON TRANSFER By V. Grosshenny, A. Harriman, M. Hissler and R. Ziessel Ecole Europkenne de Hautes Etudes des Industries Chimique de Strasbourg, Universitk Louis Pasteur, Laboratoire de Chimie d’Electronique et de Photonique Molkculaires, Strasbourg, France The concludingpart of thispaper on the use of ruthenium(ZI) and osmium(II) polypyridyl complexes, as molecular sized terminal subunits that are linked together bypolyyne bridges functioning as molecular girders to retain the stereo- chemical rigidity, deals with the process of electron transfer between the subunits and considers the benefits conferred by the use of polyyne bridges. The ruthe- nium and osmium complexes have properties which aid the selective promo- tion of an electron from the metal to the bridging ligand, together with amenable absorption and emission spectral pro+, and facile oxidation-reduction processes. This makes them promising candidates for vectorial electron transfer. Future work to extend the lengths of the linkages, to ensure unidirectional and long- range electron tunnelling, and to anchor the wires to supports is discussed. These are the necessary requirements for the development of molecular wiring made from these materials forfuture use with molecular-scale electronic devices. The first part of this paper introduced the sub- metal centres, must occur between more widely- ject of molecular wires and considered the struc- spaced reactants and it displays a more signifi- ture and chemistry of the complexes that can cant attenuation factor. be used for them, and other materials currently Interestingly, the insertion of a platinum(I1) believed to be the best for this purpose (13).
    [Show full text]
  • Chemistry and Applications of Metal-Organic Materials A
    CHEMISTRY AND APPLICATIONS OF METAL-ORGANIC MATERIALS A Dissertation by DAN ZHAO Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY December 2010 Major Subject: Chemistry Chemistry and Applications of Metal-Organic Materials Copyright 2010 Dan Zhao CHEMISTRY AND APPLICATIONS OF METAL-ORGANIC MATERIALS A Dissertation by DAN ZHAO Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Approved by: Chair of Committee, Hong-Cai Zhou Committee Members, Abraham Clearfield François P. Gabbaï Hung-Jue Sue Head of Department, David H. Russell December 2010 Major Subject: Chemistry iii ABSTRACT Chemistry and Applications of Metal-Organic Materials. (December 2010) Dan Zhao, B.A., Zhejiang University; M.S., Zhejiang University Chair of Advisory Committee: Dr. Hong-Cai Zhou Developing the synthetic control required for the intentional 3-D arrangement of atoms remains a holy grail in crystal engineering and materials chemistry. The explosive development of metal-organic materials in recent decades has shed light on the above problem. Their properties can be tuned by varying the organic and/or inorganic building units. In addition, their crystallinity makes it possible to determine their structures via the X-ray diffraction method. This dissertation will focus on the chemistry and applications of two kinds of metal-organic materials, namely, metal-organic frameworks (MOFs) and metal-organic polyhedra (MOP). MOFs are coordination polymers. Their permanent porosity makes them a good “gas sponge”. In the first section, an isoreticular series of MOFs with dendritic hexa- carboxylate ligands has been synthesized and characterized structurally.
    [Show full text]
  • Computational Chemistry
    518 CHIMIA 2012, 66, No. 7/8 Computational Chemistry doi:10.2533/chimia.2012.518 Chimia 66 (2012) 518–531 © Schweizerische Chemische Gesellschaft ComputationalChemistry ComputationalChemistry Computational Chemistry,Talk 155 Computational Chemistry,Talk 156 ExploringPhotoinduced Intermolecular Electrontransferwith Local Control Theory in Trajectory-based Nonadiabatic Dynamics Molecular Dynamics Simulations B. F. E. Curchod1,T.J.Penfold1,2,3,U.Rothlisberger1,and I. Tavernelli1 A. Gamiz-Hernandez1,E.Vauthey2,M.Meuwly1 1Laboratory of Computational Chemistry and Biochemistry, Ecole Poly- technique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland 1UniversityofBasel/DepartmentofChemistry, Klingelbergstr. 80, CH-4055 2Laboratoire de Spectroscopie Ultrarapide, Ecole Polytechnique Fédérale de Basel, Switzerland Lausanne, CH-1015 Lausanne, Switzerland 2UniversityofGeneva/DepartmentofPhysicalChemistry, 30 quaiErnest- 3SwissFEL, Paul Scherrer Inst., CH-5232 Villigen, Switzerland. Ansermet, CH-1211 Geneva 4, Switzerland In the last years, linear-response time-dependent density functional theory (LR-TDDFT) has become widely used for the calculation of vertical elec- Understandingthe dynamics of photoinduced chemical processes involving tronic excitation energies of medium to large size molecular systems in gas electron transfer(ET)isacrucialstep for the designofnew technologies and condensed phases. In addition, excited state LR-TDDFT forces and such as efficient solar energy conversion devices. Photoinduced ET pro- nonadiabatic couplings have also
    [Show full text]
  • Exciton Radiative Lifetime in a Monoatomic Carbon Chain
    Exciton radiative lifetime in a monoatomic carbon chain Stella Kutrovskaya,1,2,3 Sevak Demirchyan,1,2 Anton Osipov,3,4 Stepan Baryshev, 5 Anton Zasedatelev,5,6 Pavlos Lagoudakis,5,6 and Alexey Kavokin1,2,6,7,8 1 School of Science, Westlake University, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China 2 Institute of Natural Sciences, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China 3 Department of Physics and Applied Mathematics, Stoletov Vladimir State University, 600000 Gorkii street, Vladimir, Russia 4 ILIT RAS | Branch of FSRC \Crystallography and Photonics" RAS,1 Svyatoozerskaya, Shatura, 140700, Moscow region, Russia 5 Skolkovo Institute of Science and Technology, 30 Bolshoy Boulevard, bld. 1, 121205 Moscow, Russia 6 Physics and Astronomy, University of Southampton, Highfield, Southampton, SO171BJ, United Kingdom 7 Russian Quantum Center, Skolkovo IC, Bolshoy Bulvar 30, bld. 1, Moscow 121205, Russia 8 NTI Center for Quantum Communications, National University of Science and Technology MISiS, Moscow 119049, Russia Linear carbon-based materials such as polyyne and cumulene oligomers provide a versatile platform for nano- physics and engineering. Direct gap quasi-1D polyyne structures are promising for the observation of strong and unusual excitonic effects arising due to the two-dimensional quantum confinement. Recently, we reported on the observation of sharp exciton peaks in low temperature photoluminescence spectra of polyyne chains [1]. Here, we analyse the time-resolved optical response of this system. We extend the non-local dielectric response theory to predict the exciton radiative lifetime dependence on the bandgap value and on the length of the chain.
    [Show full text]
  • Gaining Knowledge of Single Carbon Chains
    Gaining knowledge of single carbon chains J.P. Boersma, [email protected] With thanks to: Mikhail Akhukov, Annalisa Fasolino Theory of condensed matter, Radboud University Nijmegen June 29, 2011 Contents 1 Abstract 2 2 Introduction 3 3 Computational Methods 4 4 Results & Discussion 5 4.1 Periodic & isolated carbon chains . 5 4.2 Periodic carbon chain with ribbon . 9 4.3 Isolated carbon chains with hydrogens . 10 5 Conclusion 15 6 Future Plans 16 References 17 1 1 Abstract There is not much knowledge of the behavior of nanosized parts of graphene. One interesting question is whether carbon ribbons or chains could be used to connect graphene parts and serve as a current conductor. Therefore we did calculations on 'single' graphene ribbons (benzene stripes) at first, which point out that the stripes aren't stable. Two periodic chains are formed. Instead of periodic chains we did mostly calculations on finite carbon chains, which are more relevant for our question. Previous research has shown that these chains are stable [1]. We studied the convergence of energies, distances and distance alternation in chains with periodic and free boundary conditions and in carbon chains with varying termination. These terminations were one, two or three hydrogens or a graphene ribbon. The bond lenghts, binding energies and charge densities were determined for these chains. From these properties we can conclude that adding termination to isolated carbon chains causes more alternation in bond lengths. There is a difference in formation energies and bond lengths between an even and odd number of carbon atoms in a chain and thus a difference in stability with the chain with an even number of carbon atoms being the stablest chain.
    [Show full text]
  • Linear Carbon Chains: Ultimate 1D Crystals
    Linear carbon chains: ultimate 1D crystals Alexey Kavokin International Center for Polaritonics This work has been done by A. Kucherik M. Portnoi, R. V. Samyshkin, Stella Kutrovskaya Hartmann A. Osipov, S. Arakelyan A and A Povolotsky M. Scarselli M. De Crescenzi P. Lagoudakis, A. Zasedatelev, S. Baryshev International Center for Polaritonics Growth and Fabrication Unit Quantum Nanoscience Lab Theory group Quantum Materials Lab The outline • Carbyne: an elusive allotrope of carbon • Laser ablation and stabilisation of C-chains • Deposition on a substrate • TEM and X-ray analysis, Raman spectra • Low-temperature photoluminescence reveals strong exciton features! • Conclusions Carbon hybridization and resulting nano-objects 5 Carbyne: the ultimate one-dimensional crystal Cummulene (=C=C=)n 2010 Polyyne 1996 (-C≡C-)n An elusive allotrope of carbon The most robust of all known crystals! Carbyne: high expectations CUMULENE AND POLYYNE ARE SEMICONDUCTORS CUMULENE POLYYNE The band gap predicted for infinite chains: cumulene (=C=C=)n - 0.41eV (under high pressure) polyyne (-C≡C-)n - 1 eV (atmospheric pressure) ACS-NANO, 7(11), 10075 (2013); Synthetic Metals, 17, 557(1987); Nat. Commun. 6, 6636 (2015) 8 The problem: Freestanding linear chains of over 6 atoms are theoretically unstable to bending and folding They need to be stabilized! Our method of the carbyne synthesis -CΞC- Graphene decomposition into the polyyne chains LASER HEATING OF CARBON TARGET 2 1 c B a a r n b d y y n e 1. Jagdish Narayan and Anagh BhaumikJournal of Applied Physics 118, 215303 (2015); 2. M. C. Downer et al, International Journal of Thermophysics, Vol. 14, No.
    [Show full text]
  • Jupiter's Ammonia Clouds—Localized Or Ubiquitous?
    ARTICLE IN PRESS Planetary and Space Science 53 (2005) 498–507 www.elsevier.com/locate/pss Jupiter’s ammonia clouds—localized or ubiquitous? S.K. Atreyaa,Ã, A.S. Wonga, K.H. Bainesb, M.H. Wongc, T.C. Owend aDepartment of Atmospheric, Oceanic, and Space Sciences, The University of Michigan, Ann Arbor, MI 48109-2143, USA bJet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA cAstronomy Department, University of California, Berkeley, CA 94720, USA dInstitute for Astronomy, University of Hawaii, Honolulu, HI 96822, USA Received 10 November 2003; received in revised form 9 April 2004; accepted 13 April 2004 Available online 8 February 2005 Abstract From an analysis of the Galileo Near Infrared Imaging Spectrometer (NIMS) data, Baines et al. (Icarus 159 (2002) 74) have reported that spectrally identifiable ammonia clouds (SIACs) cover less than 1% of Jupiter. Localized ammonia clouds have been identified also in the Cassini Composite Infrared Spectrometer (CIRS) observations (Planet. Space Sci. 52 (2004a) 385). Yet, ground- based, satellite and spacecraft observations show that clouds exist everywhere on Jupiter. Thermochemical models also predict that Jupiter must be covered with clouds, with the top layer made up of ammonia ice. For a solar composition atmosphere, models predict the base of the ammonia clouds to be at 720 mb, at 1000 mb if N/H were 4 solar, and at 0.5 bar for depleted ammonia of 2  10À solar (Planet. Space Sci. 47 (1999) 1243). Thus, the above NIMS and CIRS findings are seemingly at odds with other observations and cloud physics models. We suggest that the clouds of ammonia ice are ubiquitous on Jupiter, but that spectral identification of all but the freshest of the ammonia clouds and high altitude ammonia haze is inhibited by a combination of (i) dusting, starting with hydrocarbon haze particles falling from Jupiter’s stratosphere and combining with an even much larger source—the hydrazine haze; (ii) cloud properties, including ammonia aerosol particle size effects.
    [Show full text]
  • Carbon Allotrope, Cyclo[18]Carbon
    This is the author’s version of the work. It is posted here by permission of the AAAS for personal use, not for redistribution. Published in Science First release: 15 Aug 2019, DOI: 10.1126/science.aay1914 An sp-hybridized molecular carbon allotrope, cyclo[18]carbon Katharina Kaiser,1† Lorel M. Scriven,2† Fabian Schulz,1 Przemyslaw Gawel,2* Leo Gross,1* Harry L. Anderson2* 1 IBM Research–Zurich, Säumerstrasse 4, 8803 Rüschlikon, Switzerland 2 Department of Chemistry, Oxford University, Chemistry Research Laboratory, Oxford, OX1 3TA, United Kingdom † These authors contributed equally. *Corresponding authors. Email: [email protected]; [email protected]; [email protected] Abstract: Carbon allotropes built from rings of two-coordinate atoms, known as cyclo[n]carbons, have fascinated chemists for many years, but until now they could not be isolated or structurally characterized, due to their high reactivity. We generated cyclo[18]carbon (C18) using atom manipulation on bilayer NaCl on Cu(111) at 5 Kelvin by eliminating carbon monoxide from a cyclocarbon oxide molecule C24O6. Characterization of cyclo[18]carbon by high-resolution atomic force microscopy revealed a polyynic structure with defined positions of alternating triple and single bonds. The high reactivity of cyclocarbon and cyclocarbon oxides allows covalent coupling between molecules to be induced by atom manipulation, opening an avenue for the synthesis of other carbon allotropes and carbon-rich materials from the coalescence of cyclocarbon molecules. 1 The discovery of fullerenes (1), carbon nanotubes (2), and graphene (3), all of which consist exclusively of 3-coordinate carbon atoms, has sparked a new field of synthetic carbon allotropes (4, 5).
    [Show full text]
  • Data-Driven UPLC-Orbitrap MS Analysis in Astrochemistry
    life Article Data-Driven UPLC-Orbitrap MS Analysis in Astrochemistry Alexander Ruf 1,∗ , Pauline Poinot 2, Claude Geffroy 2 , Louis Le Sergeant d’Hendecourt 1 and Gregoire Danger 1,* 1 Laboratoire de Physique des Interactions Ioniques et Moléculaires (PIIM), Université Aix-Marseille, Saint Jérôme—AVE Escadrille Normandie Niemen, 13013 Marseille, France; [email protected] (A.R.); [email protected] (L.L.S.d.) 2 Institut de Chimie des Milieux et Matériaux de Poitiers (IC2MP), Université de Poitiers, UMR CNRS 7285, 86073 Poitiers, France; [email protected] (P.P.); [email protected] (C.G.) * Correspondence: [email protected] (A.R.); [email protected] (G.D.); Tel.: +33-491288285 (G.D.) Received: 30 March 2019; Accepted: 23 April 2019; Published: 2 May 2019 Abstract: Meteorites have been found to be rich and highly diverse in organic compounds. Next to previous direct infusion high resolution mass spectrometry experiments (DI-HR-MS), we present here data-driven strategies to evaluate UPLC-Orbitrap MS analyses. This allows a comprehensive mining of structural isomers extending the level of information on the molecular diversity in astrochemical materials. As a proof-of-concept study, Murchison and Allende meteorites were analyzed. Both, global organic fingerprint and specific isomer analyses are discussed. Up to 31 different isomers per molecular composition are present in Murchison suggesting the presence of ≈440,000 different compounds detected therein. By means of this time-resolving high resolution mass spectrometric method, we go one step further toward the characterization of chemical structures within complex extraterrestrial mixtures, enabling a better understanding of organic chemical evolution, from interstellar ices toward small bodies in the Solar System.
    [Show full text]