Synthesis, optical, electrochemical, and thermal properties of conjugated α-fluorenyl oligothiophenes

A series of new α-fluorenyl oligothiophenes up to the pentamer have been synthesized using Suzuki cross-coupling and bromination reactions. The optical, electrochemical, and thermal properties of these materials can be tuned by varying the number of thiophene rings. The longer oligomers (n ⩾ 4) were stable, crystalline, and unreactive to electrochemical oxidative dimerization.