Formation and Structures of Dimeric Compounds from an (E)-5,5′-Diphenyl-2,2′,3,3′-tetrahydro-3,3′-bipyrrolylidene-2,2′-dione

Dimeric fluorescent compounds were formed from an (E)-5,5′-diphenyl-2,2′,3,3′-tetrahydro-3,3′-bipyrrolylidene-2,2′-dione by a treatment with acid anhydride and TFA. The structures of these compounds were clarified by X-ray analysis and spectral (UV-vis, 1H and 13C NMR) comparisons.