Metastable Solution Structures of Spirobenzoselenazolinobenzopyrans and Their Negative Photochromic Properties

Abstract

Abstract A series of photochromic 6′-nitro-3-octadecylspirobenzoselenazolinobenzopyrans have been newly prepared and their solution structures of the colored form have been confirmed as 3-octadecylbenzoselenazolenium-2-trans-1′-cis-(5′-nitrostyryl-2′-oxide) by selective partial deuteration and NMR techniques. Photochromic repetition of these compounds for 50% fatigue attained the number more than ca. 800 times.