Theoretical and experimental study of donor-bridge-acceptor system: model 2-[5-(9H-fluoren-9-ylidenemethyl)thiophen-2-yl]-1,3,4-oxadiazole derivatives

The theoretical study of the titled model acceptor-bridge-donor molecular series based on 9H-fluoren-9-ylidenemethyl and 1,3,4-oxadiazole heterocycles is presented. The subunits are linked through a thienyl moiety, and the second alpha-site of oxadiazole was modified. The quantum chemical model indicated that the electron-donating properties of 9H-fluoren-9-ylidenemethyl were significantly supported or suppressed by the terminal substitution of 1,3,4-oxadiazole which affected the possible semiconductivity. Finally, the possible synthesis of selected molecules is described, and the prepared derivatives were fully characterized by H-1 NMR, C-13 NMR, IR, and elemental analysis together with optical and electrochemical measurements.