The electronic spectrum of nitrosomethane, CH 3 NO

Abstract

A spectrum of a metastable molecule has been observed in the region 6000 to 7100 Å after flash photolysis of t -butyl nitrite. The analysis of this spectrum strongly suggests that the absorption is due to a π * — n (N) transition of nitrosomethane, and that the largest geometry change on electronic excitation is an increase by about 8° in the CNO angle. Unusual vibrational features in this spectrum are interpreted in terms of a decrease in the barrier to torsion of the CH 3 group about the CN bond from 940 ± 200 cm -1 in the ground state to 290 ± 50 cm -1 in the excited state.