Efficient synthesis of regioisomerically pure bis(trifluoromethyl)-substituted 3,4,9,10-perylene tetracarboxylic bis(benzimidazole).

By a new strategy, two trifluoromethyl groups were efficiently introduced to highly insoluble n-type semiconductor 3,4,9,10-perylene tetracarboxylic bis(benzimidazole) (PTCBI), and for the first time we obtained three pure regioisomers of bis(trifluoromethyl)-substituted PTCBI, whose optical properties are different from one another.