1-octadecyl- and 3,3-diphenyl-substituted photochromic indolinospirochromenes

Abstract

A number of photochromic indolinospirochromenes that contain an octadecyl substituent in the 1 position were synthesized. The introduction of an octadecyl group in place of a methyl group increases the stability of the merocyanine form in solution but does not change its spectral characteristics. On the other hand, the introduction of phenyl groups in place of methyl groups in the 3 position does not change the stability of the merocyanine but gives rise to a bathochromic shift of the long-wave absorption band.