TETRATHIAFULVALENE-SUBSTITUTED AND DITHIAFULVENE-SUBSTITUTED MESITYLENES, NEW PI-DONOR MOLECULES WITH 3-FOLD SYMMETRY AND THE FORMATION OF AN UNPRECEDENTED NEW CLASS OF ELECTROACTIVE POLYMERS

Novel pi-donor molecules with 3-fold symmetry are built on the 1,3,5-benzene core, substituted with three identical moieties, i.e. -CH=CH(TTF) (8) (TTF = tetrathiafulvalene), -CH2S((TTF)Me3) (9), 1,4-dithiafulven-6-yl (10a,b), and 6-methyl-1,4-dithiafulven-6-yl (11a,b). Cyclic voltammetry experiments demonstrate that oxidation of 10a,b gives rise to the precipitation of an electroactive polymer on the electrode, while 9 can be reversibly oxidized to 9(3+) and 9(6+). Electrocrystallization of 9 in the presence of TBA2(Mo6Cl14) affords crystals Of (9(2+)).Mo6Cl142-, whose magnetic properties are investigated by EPR. 10a crystallizes in the monoclinic system, space group P2(1)/c, with a = 3.986(1) angstrom, b = 21.312(2) angstrom, c = 20.473(2) angstrom, beta = 94.24(1)degrees, and Z = 4. 11a crystallizes in the monoclinic system, space group P2(1)/a, with a = 10.919(4) angstrom, b = 17.175(2) angstrom, c = 11.481(1) angstrom, beta = 97.86(2)degrees, and Z = 4. Columns of planar molecules of 10a are exquisitely interlocked to create a dense (d(calcd) = 1.61 g cm-3) solid whereas no stacking pattern is observed in the structure of the nonplanar, puckered molecule 11a (d(calcd) = 1.44 g cm-3). MO calculations demonstrate that, because of their meta orientation, the three dithiolyidene fragments in 10a and 11a are nearly independent.