Effect of Imino Nitroxyl and Nitronyl Nitroxyl Groups on the Photochromic Reactivity of Diarylethenes

Diarylethene derivatives having imino nitroxide and nitronyl nitroxide have been prepared to examine the effect of the radical substituents on
the photochromic reactivity of 1,2-bis(2-methyl-1-benzothiophen-3-yl)perfluorocyclopentene. These radical substituents reduce the quantum
yields of both cyclization and cycloreversion reactions. The nitronyl nitroxyl moiety is more effective to suppress the reactivity in comparison
with the imino nitroxide moiety.