Laser flash photolysis of carbamates derived from 9-fluorenone oxime

Article abstract of DOI:10.1021/ja00118a021

The photochemistry of carbamates derived from 9-fluorenone oxime was investigated by laser flash photolysis and by product studies. Primary photocleavage of the excited carbamates leads to decarboxylation and concomitant generation of the 9-fluorenone ketimine-N-yl radical and an amino radical. In the case of 9-fluorenylideneamino N-(2,5-dimethoxyphenyl)carbamate the presence of 1,4-dimethoxybenzene in the product mixture as well as spectroscopic and kinetic evidence points to the intermediary formation of triplet (2,5-dimethoxyphenyl)nitrene, which in acetonitrile dimerizes to the corresponding azo compound. Analogously, the formation of trans-azobenzene upon photolysis of 9-fluorenylideneamino N-phenylcarbamate indicates the intermediacy of parent triplet phenylnitrene, which, until now, had not been observed in solution at ambient temperature.