Bis(thioxo-diethylthiotetrathiafulvalenyl)ylidene, a new donor molecule with high electron-donating ability comparable to tetrathiafulvalene

A new donor molecule, bis(thioxo-diethylthiotetrathiafulvalenyl)ylidene (1) was obtained by the iodine oxidation of bis(tetraethylammonium) bis(2,3-di ethylthiotetrathiafulvalenyl-6, 7-dithiolato) zinc complex (3). The molecul ar skeleton of 1 except for the four ethyl groups is almost planar and sign ificant intramolecular S-S contact is present. The redox process of 1 is co mposed of four electron-transfer steps, of which the first step has almost the same redox potential (+0.40 V vs. Ag/AgCl) to that of tetrakis(ethylthi o)tetrathiafulvalene (TET-TTF). Very interestingly, 1 exhibited longest-wav elength electronic absorptions near 1100 nm.