Synthesis and Characterization of New Xanthene Derivatives, and Their Electrochemical Study

This work investigated the synthesis of biphenyl-3,3', 4,4'-tetracarboxylic dianhydride and benzophenone-3,3', 4,4'-tetracarboxylic dianhydride derivatives (3a-e and 6a-e) with different substituted phenols via Friedel-Crafts acylation reaction in the presence of dilute sulfuric acid. Dianhydride derivatives with 3-N, N'-dimethylamino phenol (3d and 6d) and resorcinol (3e and 6e) have been found to be highly fluorescent. The structures of all newly synthesized compounds were confirmed by the chromatographic, spectral and elemental data. Electrochemical study was done to determine to band gap energy, LUMO and HOMO levels energy. Band gap and LUMO energy levels were found to be lowest in xanthene derivatives substituted with 3-N, N'-dimethylamino group having value 2.24 and 4.85 eV respectively.