CRYSTAL-STRUCTURES AND MOLECULAR PACKING OF TETRAKIS(ALKYLTHIO)-TETRATHIAFULVALENE (TTCN-TTF) .1. (N=3,4,6)

The crystal structures of tetrakis(alkylthio)tetrathiafulvalene TTC(n)-TTF (n=3, 4, 6) were determined by X-ray analysis. The structures of TTC(n)-TTF drastically changed between n=3 and 4. The TTC3-TTF molecule has a boat-like shape, like that of TTC1-TTF and TTC2-TTF. On the other hand, the TTC4-TTF and TTC6-TTF molecules have chair-like shapes, like that of TTC5-TTF, and columnar structures with intermolecular effective overlaps between the central pi-systems. These results can explain the drastic change in the electrical properties between n=3 and 4.