A series of 2,5-diphenyl-3,4-distyrylcyclopenta-2,4-dienone (3a-i) and 2,5-diphenyl-3,4-bis((1E,3E)-4-phenylbuta-1,3-dienyl)cyclopenta-2,4-dienone (5) have been synthesized by the condensation of various (1E,5E)-1,[-diarylhexa-1,5-diene-3,4-dione (1a-i) and (1E,3E,7E,9E)-1,10-diphenyldeca-1,3,7,9-tetraene-5,6-dione (4) with 1,3-diphenylpropan-2-one (2) using sodium hydride in dichloromethane. Electronic absorption and emission spectral studies have shown an efficient π-interaction due to the extended conjugation in the cyclopentadienones (3a-i, 5). The electronic excitation in the near UV-region (250-390 nm) to strong emission near (500-690 nm), allowing these to consider as light-harvesting species.

Syeda Shaista Gillani, Munawar Ali Munawar, Khalid Mohammed Khan and Ch. Jamil Anwar