The foci of this research include five areas of silicon and related organic chemistry. First, new materials containing positive charge on silicon, germanium, tin and phosphorus will be prepared. Second, methods will be employed to create a variety of stable carbocations, usually stabilized by silicon, at room temperature. Third, dendritic polysilanes will be prepared and tested for their conductive and nonlinear optical properties, and in one case as a molecular wire. Fourth, a new area of sulfur chemistry will be developed in which sulfur substituents are exploited to stabilize positive charge. Fifth, the practical properties of silicates will be used to synthesize a new class of materials that are largely self assembling, have considerable stability, offer vacancies and channels for inclusion of guests, and contain synthetically tunable groups that can enhance these properties. With this renewal award, the Organic and Macromolecular Chemistry Program is supporting the research of Dr. Joseph B. Lambert of the Department of Chemistry at Northwestern University. Professor Lambert will focus his work on incorporating silicon into normal analogues of carbon compounds or into novel structures to create molecules with potentially important properties. The properties may be of theoretical interest or they may offer new practical applications. The scope of the project is increased by including germanium, tin sulfur and phosphorus in the synthetic plan
