Photoreactions of alkylated 2-pyridones

Abstract

Photoisomerisation and dimerisation reactions in solution have been studied with a series of alkylated 2- pyridones (1). The low quantum efficiencies for the photoisomerisation (0.01–0.07) are related to the short-lived singlet excited states (below 1 ns). The effects of temperature, solvent, and substrate concentration were also examined. The photodimerisation reactions of (1) are considered to involve preliminary association via strong dipole–dipole interaction rather than hydrogen-bonded pairing.