Mixed conducting Langmuir-Blodgett films of a novel charge-transfer complex TBT-TTF-Cu(dmit)2

A new charge-transfer complex, TBT-TTF-Cu(dmit) 2 (where TBT-TTF is tetrakis(benzylthio)tetrathiafulvalene), as a LB film material is synthesized. The LB films are constructed by using a 1:1 molar mixture of this complex with stearic acid (SA). The degrees of charge transfer are determined to be 0.18 and 0.11 according to Raman frequencies of ν C-S and ν C=C before and after iodine oxidation. It is shown that the latter mixed-valence compound is formed after continuous changes induced by the iodine intercalation, which leads to the new conducting phase. The existence of triiodide chains has been proved by Raman frequencies and UV absorption spectra. The results of conductivity measurements show that the conductivities increase with an increase in TBT-TTF-Cu(dmit) 2 molar fraction and that the LB films exhibit conductive anisotropy