THE SYNTHESIS, REDOX PROPERTIES AND X-RAY CRYSTAL-STRUCTURES OF 2 NEWTETRATHIAFULVALENE-THIOPHENE DONORS

The functionalisation of tetrathiafulvalene with thiophene units is re ported via the synthesis of two multiredox compounds 4 and 5. The two molecules represent a fused structure (4) and a TTF-thiophene system d irectly linked by a single bond (5); both compounds are endowed with ' free' 2,5-positions within the thiophene ring, making them accessible to polymerisation reactions. The solution electrochemistry of 4 and 5 reveals the redox properties of the two components: a three-stage oxid ation process is seen in each case. Charge-transfer complexes have bee n prepared, using TCNQ or TCNQF(4) as the electron acceptor, with cond uctivities in the range of 10(-4) to 0.22 S cm(-1). Compounds 4 and 5 have been studied by X-ray crystallography; the former exhibits kappa- packing whilst the latter shows a high degree of conjugation between t he two donor moieties.