Robert C. West - US grants

This Organic and Macromolecular Chemistry project is directed towards the development of new carbon-silicon and carbon-boron synthetic methods, which will permit the preparation of unique, new, polymeric materials of theoretical and practical interest. New kinds of multiply bonded molecules of silicon and boron will be synthesized and characterized. The organosilicon and organoboron species to be prepared include (1) Disilynes and their polymerization products; (2) Stable 1,4- and 1,2- disilabenzenes; (3) Stable silanediimines; (4) Silynes; (5) Borenes and Diborenes; and (6) Boranones.

The Synthetic Organic Program will support the research of Dr. Robert West of the Department of Chemistry at the University of Wisconsin-Madison. Dr. West will continue his innovative studies of compounds compounds containing silicon, with a focus on compounds containing multiply-bonded silicon. The new types of multiply-bonded silicon compounds that will be synthesized and characterized include disilynes, silynes, silanamidides, silandiimines, sila(iso)nitriles and 1,2-disilabenzenes.

This award will provide supplementary support to enable Dr. Robin Tan of the University of Wisconsin, Madison, to conduct collaborative research with Dr. Masato Tanaka for 24 months at the National Chemical Laboratory for Industry in Tsukuba, Japan. Tan and Tanaka will utilize Tan's expertise in silicon chemistry to synthesize new organosilicon compounds. With future applications for lithography, new organosilicon compounds can be used to develop new polymeric materials. Tan and Tanaka propose a new method to synthesize organosilicon species by utilizing low valent metal complexes as catalysts. By varying the starting silicon and unsaturated organic compounds, they will be able to form many novel organosilicon compounds which will serve as important starting materials in the synthesis of silicon-based polymeric materials. Dr. Tanaka's experience in silicon-based polymeric materials and the instrumentation available in his laboratory will complement Dr. Tan's experience in synthesizing organometallic compounds.

Tan This award will provide supplementary support to enable Dr. Robin Tan of the University of Wisconsin, Madison, to conduct collaborative research with Dr. Masato Tanaka for 24 months at the National Chemical Laboratory for Industry in Tsukuba, Japan. Tan and Tanaka will utilize Tan's expertise in silicon chemistry to synthesize new organosilicon compounds. With future applications for lithography, new organosilicon compounds can be used to develop new polymeric materials. Tan and Tanaka propose a new method to synthesize organosilicon species by utilizing low valent metal complexes as catalysts. By varying the starting silicon and unsaturated organic compounds, they will be able to form many novel organosilicon compounds which will serve as important starting materials in the synthesis of silicon-based polymeric materials. Dr. Tanaka's experience in silicon-based polymeric materials and the instrumentation available in his laboratory will complement Dr. Tan's experience in synthesizing organometallic compounds. Dr. Tanaka's laboratory is participating in a national Japanese government project on silicon chemicals and silicon-based materials.

The focus of this research is the preparation of silaallenes, silynes, borasilenes and diborenes. Attempts will be made to prepare fullerenes containing one or more silicon atoms in the cage and to construct polymers containing fullerene clusters linked by siloxane or polysilane moieties. %%% With this renewal award the Synthetic Organic Program is supporting the research of Dr. Robert West of the Department of Chemistry at the University of Wisconsin, Madison. Professor West will focus his work on the synthesis of multiply-bonded silicon and boron compounds, the preparation of silicon derivatives of the fullerenes and polymers containing fullerene clusters.

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West
This project will support a program of research on organosilicon polymers. Materials to be synthesized and studied will include (a) new types of polysilanes with properties which may make them useful as fluorescent materials for radiation detection, as electroluminescent materials for display devices, as photoconductors, and as photorefractive materials for holographic data storage; (b) polysiloxanes which will complex alkali metal ions and may be useful as electrolytes in high energy-density batteries; and (c), polymers containing fullerene (C60) molecules which may be superior photoconductors and organic semiconductors.
In addition, the electronic properties of polysilanes will be investigated. UV, Raman, NMR and fluorescence spectroscopy, combined with thermal measurements and X-ray crystallography, will be employed to elucidate the effects of conformational change on the properties of polysilanes.
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This research is in the field of novel, silicon-based materials, which can have important potential applications in the areas of electronic and photonic devices.
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With the support of the Organic Synthesis Program, Professor Robert West, of the Department of Chemistry at the University of Wisconsin, studies the synthesis, structure, and bonding of multiply-bonded and low-coordinate silicon and germanium compounds. Specific classes of compounds under investigation include silynes, disilynes, metallole dianions, and metallacalicenes, as well as other compounds containing new types of double bonds between silicon or germanium and other atoms. Professor West is also exploring the chemistry of stable dicoordinate silicon compounds (silylenes) and their complexes with transition metals and the vaporization of carbon in the presence of silicon tetrachloride, producing silicon-containing fullerene derivatives.

Many questions remain unanswered about the nature of chemical bonding, particularly with regards to the bonding between elements other than carbon. Professor Robert West, of the Department of Chemistry at the University of Wisconsin, is supported by the Organic Synthesis Program for his studies of the synthesis and structure of compounds containing silicon and germanium atoms displaying unusual chemical bonding motifs. Of particular interest to Professor West are those compounds which display multiple bonds to these elements (e.g., silicon-carbon and silicon-silicon triple bonds) and those in which these elements bear fewer bonds than usual (e.g., dicoordinate silicon compounds). Finally, by inclusion of chemical sources of silicon atoms in the carbon vaporization synthesis of fullerenes ("Bucky balls"), Professor West is preparing silicon-containing fullerenes. Observations from each of these studies promise to afford fundamental advances in our understanding of the nature of chemical bonding.

With the support of the Organic and Macromolecular Chemistry Program, Professor Robert West, of the Department of Chemistry at the University of Wisconsin, Madison, is exploring mulitply-bonded and low-coordinate compounds of silicon and germanium. Professor West synthesizes new types of organosilicon and organogermanium compounds containing multiple bonds, including silynes (RSiCR'), germynes (RGeCR'), 1,3-disilaallenes (R2Si=C=SiR2), 1,3-digermaallenes (R2Ge=C=GeR2), polysilyne polymers [(RSi=CR')n], and silafullerenes such as C58Si2. He then studies the chemical reactions of these unusual molecules, including their activity as polymerization catalysts and as precursors to stable silylenium ions, and their halophilic reactions.

Although our understanding of the chemistry of compounds containing carbon has become quite sophisticated, the chemistry of carbon's closely related relatives, silicon and germanium, is comparatively undeveloped. Professor Robert West, of the Department of Chemistry at the University of Wisconsin, Madison, is studying the synthesis and reaction chemistry of a series of compounds in which one or more carbon atoms are replaced by silicon or germanium. These studies are of fundamental importance in developing our understanding of the chemistry of the other elements in the periodic table. In addition, the unusual structures of Professor West's target compounds promise potential advances in practical reaction chemistry, including polymerization reactions.

This project addresses the fundamental chemistry of unusual heavy-metal congeners of carbon compounds. Metallole dianions - five-membered ring compounds containing silicon, germanium or tin atoms - bear two negative charges which are delocalized over the rings. Reactions of these unique dianions are expected to give rise to a wide range of novel compounds containing metal-to-carbon double bonds, as well as to a remarkable series of stable diradicals, containing two unpaired electrons. The synthesis and chemistry of stable silylenes - compounds of silicon in the unusual oxidation state of 2 rather than the customary 4 - will also be explored. The process by which some stable silylenes serve as catalysts for the polymerization of unsaturated organic compounds will be investigated.

With this award, the Organic and Macromolecular Chemistry Program is supporting the research of Professor Robert West, of the Department of Chemistry at the University of Wisconsin - Madison. Although our understanding of the chemistry of compounds containing carbon has become quite sophisticated, the chemistry of carbon's closely related relatives, silicon and germanium, is comparatively undeveloped. Professor West is studying the synthesis and reaction chemistry of a series of compounds in which one or more carbon atoms are replaced by silicon, germanium or tin. These studies are of fundamental importance in developing our understanding of the chemistry of the other elements in the periodic table. In addition, the unusual structures of Professor West's target compounds promise potential advances in practical reaction chemistry, including polymerization reactions.