Synthesis and spectral properties of photochromic cyclopentenone diarylethenes with an additional π system in the ethene bridge

Photochromic diarylethenes with an additional p system in the ethene bridge were synthesized by the condensation of 2,3-bis(2,5-di- methyl-3-thienyl)cyclopent-2-en-1-one with aromatic aldehydes. Absorption bands maxima of the initial and cyclic forms of the substances were determined and their thermal stability was studied.