Tetrafluoro and dichloro derivatives of thiophene-fused DCNQI- and TCNQ-type acceptors: A synthetic, electrochemical and crystallographic study

Novel thiophene-fused DCNQI derivatives 8 and 11 bearing four fluorine atoms have been obtained in good yield from the corresponding quinones by reaction with bis(trimethylsilyl) carbodiimide (ETC): The presence of four fluorine atoms leads to good acceptor molecules which form charge transfer complexes in solution with N,N'-tetlamethyl-p-phenylenediamine. The effect of chlorine atoms on the crystal packing in the analoguous thiophene-fused TCNQ derivatives 3a and 3b is also reported.