Infrared spectrum of 2-hydroxyphenoxyl radical and photoisomerization between trans and cis 2-hydroxyphenyl nitrites

UV photolysis of 2-nitrophenol in an argon matrix produced 2-hydroxyphenoxyl radical through an intermediate of 2-hydroxyphenyl nitrite. Both syn-trans and syn-cis 2-hydroxyphenyl nitrite isomers were produced in annealing at 27 K after UV irradiation. The latter changed to the former upon visible-light irradiation.