Pure Appl. Chem., 2003, Vol. 75, No. 8, pp. 999-1020
doi:10.1351/pac200375080999
σ Bonds: Electronic structure, photophysics, and photochemistry of oligosilanes*
H. A. Fogarty, D. L. Casher, R. Imhof, T. Schepers, D. W. Rooklin, and J. Michl**
Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO 80309-0215, USA
Abstract:
The making and breaking of σ bonds is an integral part of almost all photochemical reactions. Yet, the electronic states of σ electrons are not nearly as well understood as the states of π-electron systems. Efforts in our laboratory to enhance the current state of their understanding are described, using the specific example of oligosilanes. We address the intrinsically cyclic nature of σ delocalization and its dependence on chain length and conformation, both in terms of theory and spectroscopic experiments, from the simplest disilane chromophore to the spectral properties of the individual conformers of permethylated heptasilane. We also describe a new low-energy luminescence from certain conformers of permethylated oligosilanes.
*Lectures presented at the XIXth IUPAC Symposium on Photochemistry, Budapest, Hungary, 1419 July 2002. Other presentations are published in this issue, pp.9991090.
**Corresponding author.
All articles from the XIXth IUPAC Symposium on Photochemistry, Budapest, Hungary, 14–19 July 2002.