Comparison of photochromic properties and thermal stabilities of fulgide, fulgimide, and benzimidazole[1,2-a]pyrrolidine-2-one derivatives

New thermally stable photochromic fulgimides and benzimidazole[1,2-a]pyrrolidin-2-one derivatives of furylfulgide and thienylfulgide were prepared and their photochromic properties were investigated. Thermal stabilities of some of the new isomers in an alcoholic solution and in PMMA (poly(methyl methacrylate)) polymer films, and pyrolytic behaviors in inert atmosphere with TGA were compared.