Highly stable photochromic crystalline material based on a close-packed layered metal–viologen coordination polymer

Abstract

Suitable combination of organic fragments N-(3-carboxyphenyl)-4,4′-bipyridinium and m-benzene dicarboxylate affords a new type photochromic metal–viologen coordination polymer with close packed arrangements. The aggregates build an interesting stable crystalline framework showing long lived color constancy. Repeating cycles of reversible color changes are observed for the molecular switch in air upon photoirradiation.