Abstract: The photolytic processes of N-phenyl-α-naphthylamine and N-phenyl-β-naphtylamine in benzene solution have been studied by ESR method. Three intermediates, H·, C₆H₅(H)N· and C₁₀H·₇ free radicals, could be detected in the photoreaction system. It is interesting that the carbon-centered free radicals are produced in the processes of photolysis, which implies that the cleavage of C-N bond takes place and C₁₀H·₇ free radicals are produced. Furthermore, research results also show that the ratio of spin adductings can be changed by adjusting the relative concentration of spin trap and the addition of photosensitizer C₆H₅COC₆H₅. In order to ascertain the mechanism of photoreaction processes, some semi-empirical calculations of quantum chemistry were also carried out.

Key words: N-phenyl-naphthylamine, Photolysis, ESR, Cleavage energy