Reprinted from J. Photochem. Photobiol. A: Chem., 110, 243-246 (1997).

© Elsevier, 1997.

A Time-Resolved Spectroscopic Study of the Chemistry of 1,1-Dimethylsilene in Solution

Corinna Kerst, Rabah Boukherroub, and William J. Leigh*

Contribution from the Department of Chemistry, McMaster University, Hamilton, Ontario, Canada L8S 4M1

Abstract: Far-UV (193-nm) laser flash photolysis of nitrogen-saturated isooctane solutions of 1,1-dimethylsiletane allows the direct detection of 1,1-dimethylsilene, as a transient species which (at low laser intensities) decays with pseudo-first order kinetics (t ~ 10-µs) and exhibits a UV absorption spectrum with l_max ~ 255-nm. Characteristically rapid quenching is observed for the silene with methanol (k_MeOH = (4.9 ± 0.2) x 10⁹ M^-1s^-1), tert-butanol (k_BuOH = (1.8 ± 0.1) x 10⁹ M^-1s^-1), and oxygen (k_O2 = (2.0 ± 0.5) x 10⁸ M^-1s^-1). Arrhenius activation parameters for the reaction with methanol have been determined to be E_a = -2.6 ± 0.6 kcal/mol and log A = 7.7 ± 0.3.