Photoinduced α-Cleavage of 2-Azido-2-phenyl-1,3-indandione at Cryogenic Temperatures.

ABSTRACT

To expand the utility of α-cleavage at cryogenic temperatures, we investigated the photoreactivity of 2-azido-2-phenyl-1,3-indandione (1). EPR spectroscopy revealed that irradiating 1 in 2-methyltetrahydrofuran (mTHF) matrices forms alkylnitrene 32, which has zero-field splitting parameters (D/hc = 1.5837 cm-1; E/hc = 0.0039 cm-1) typical of an alkylnitrene. IR spectroscopy demonstrated that irradiating 1 in argon matrices results in the concurrent formation of 32, imine 3, benzocyclobutenedione 4, and benzonitrile 5.