Nitrene-carbene rearrangement during photolysis of 2-azido-1,3,5-triazines in argon matrices

It was shown using IR spectroscopy and ESR spectroscopy that UV irradiation of 2-azido-4,6-dichloro-1,3,5-triazine isolated in solid argon resulted in triplet 4,6-dichloro-1,3,5-tri-azinyl-2-nitrene ( D = 1.384 cm −1 , E = 0.004 cm −1 ), whose further photochemical transformation included the consecutive formation of 3-didehydro-1,2,4,6-tetraazepine, 2-chloro-1-diazochloromethyl-2-isocyanocarboimide, and presumably triplet 2-chloro-1-chloromethyl-idene-2-isocyanocarboimide and isocyanodichloroacetonitrile. The photolysis of 2-azido-4,6-dimethoxy-1,3,5-triazine and 2-azido-4,6-di(dimethylamino)-1,3,5-triazine affords photo-chemically stable triplet 4,6-dimethoxy-1,3,5-triazinyl-2-nitrene ( D = 1.436 cm −1 , E = 0.0044 cm −1 ) and 4,6-bis(dimethylamino)-1,3,5-triazinyl-2-nitrene ( D = 1.468 cm −1 , E = 0.0042 cm −1 ) as the final products.