Structure and Energetics of Macromolecular Systems: POSS, Metal Clusters and other Oligomeric Molecules.

摘要

Work has been completed in three areas of research. The first is in characterization of polyhedral oligomeric silsesquioxanes (POSS) and their attachment to backbones of organic-based oligomers. Using ion mobility, we have structurally characterized a wide variety of POSS species attaining good agreement with x-ray structures when available. We have also characterized di- and tri-siloxanes, POSS cages covalently bound via oxygen bridges. Most recently we have been able to insert a fluoride ion into the cage which should make detection of larger POSS/oligomer systems feasible. The second area of research deals with organic oligomeric systems. We have focused on systems with potential for opto-electronic or organo-electronic device formation. Successful work has been completed on a series of polyphenyl vinylenes and several paracyclophanes. Finally, we have generated and characterized the structures and ligand binding energies of both anionic and cationic gold and silver clusters (n = 2 to 13). These systems have been shown to have size-dependent catalytic behavior for double bond oxidation in small alkenes when dispersed on titanium oxide surfaces. We have focused on C2H4 and CH3CHCH2 due to their industrial importance.