S. Jockusch, I. Koptyug, P. Mcgarry
Nov 26, 1997
Citations
1
Influential Citations
85
Citations
Quality indicators
Journal
Journal of the American Chemical Society
Abstract
The photophysics (2,4,6-trimethylbenzoyl)diphenylphosphine oxide (1) and bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide (4) have been investigated by fluorescence, phosphorescence, and low temperature time resolved electron spin resonance. Both 1 and 4 undergo α-cleavage to produce benzoyl and phosphorous centered radicals. The photochemistry of 1 and 4 has been investigated by nanosecond laser flash photolysis, picosecond pump-probe spectroscopy, and steady-state photolysis. The singlet states of 1 and 4 and the phosphorous centered radicals produced by α-cleavage were characterized directly by time resolved absorption spectroscopy. The triplet states of 1 and 4 were characterized indirectly by quenching with 1-phenylnaphthalene as a selective triplet quencher. The use of 1-phenylnaphthalene indicates that α-cleavage occurs mainly from the triplet states of 1 and 4. However, the observed rate of formation of phosphorous centered radicals derived from picosecond investigations is experimen...