SYNTHESIS AND PROPERTIES OF NEW BRIDGED TETRATHIAFULVALENES

The condensation reaction of dithiole phosphonium perchlorates 17 and 18a-c with 2-ethylselenodithiolium tetrafluoroborate 16 in the presence of triethylamine was employed for the high-yield synthesis of four new donors 7a-c, 9 of the tetrathiafulvalene series. The carbomethoxy groups of 7a-c were removed by basic hydrolysis followed by decarboxylation to give 8a-c. Electrochemical studies for seven new TTFs were carried out. An unusual effect resulting in an decrease of the first oxidation potential was observed for 7b. Some properties of the starting 4-mercapto-5-carbomethoxy-1,3-dithiole-2-thione (10) are reported.