Bond-Coupled Electron Transfer Processes: Cleavage of Si−Si Bonds in Disilanes
journal contributionposted on 16.02.2005, 00:00 by Rabih O. Al-Kaysi, Joshua L. Goodman
Photooxidation of 1,1,2,2-tetra-tert-butyl-1,2-diphenyldisilane, 1, by triplet sensitizers in CHCl3/CCl4 solutions yields chlorosilane, 2, in high chemical yield. The quantum yield for formation of 2 depends on the energy of the ion radical pair formed following initial electron transfer. Dissociative return electron transfer (DRET) is proposed as the mechanism for the highly efficient Si−Si bond cleavage in 1. DRET may be a useful strategy for the fragmentation of other such bonds in di-, oligo-, and polysilanes as well as other group 4A compounds using a variety of sensitizers with different spectral properties.