Photochromism of 6′-cyanosubstituted spirooxazines in frozen alcohol matrices

Abstract

For three 6′-cyanosubstituted spironaphthooxazines, spectral characteristics of an open form and quantum yields of photoisomerization were determined both at room temperature and in frozen alcohol matrices. Spironaphthooxazines have demonstrated fairly high (0.01–0.02) quantum yields of open form appearance at 77 K. The observed peculiarities of the open form UV spectra were explained by the temperature dependence of the open form isomers distribution. Partial stabilization of the nonequilibrium isomers of an open form in the low-temperature matrices was revealed.