Theoretical study of the ring-opening reactions of 2H-azirines - a classification of substituent effects

Based on CASSCF and CASPT2 calculations, the mechanisms of the photoreactions of 2H-azirines are discussed. A general classification of substituent effects on non-adiabatic singlet photoreactions is presented, and the effect of phenyl substituents on the photochemistry of 2H-azirine, including the wavelength dependence of the photochemistry of 3-phenyl-2H-azirine, is discussed in detail. Copyright (C) 2002 John Wiley Sons, Ltd.