Evidence for the participation of an isomerization pathway in diazirine photolysis. Study of primary processes and energy partitioning

Abstract

CNDO/S calculations have allowed the band centred at 322.9 nm in the photolysis of diazirine to be considered as an A″â†�A′ transition. Correlation diagrams constructed using 3H-diazirine as a model and with the conservation of individual electronic angular momenta are used to explain some of the unusual features in the decomposition reactions of diazirines. Calculated energy-partitioning data indicate that there are two photodecomposition pathways with differing efficiencies in converting available energy into internal energy. Evidence shows that diazo-compounds are intermediates in diazirine photolysis and that the efficiency of this pathway accounts for 25% of the total reaction.