New molecular combinations for spontaneous mixed valence state formation between EDO-TTF derivatives and carboxylic acids

We observed mixed valence state (MVS) formation for the molecular combinations of newly synthesized oxygen substituted tetrathiofulvalene derivatives (ethylenedioxytetratiafulvalene, EDO-TTF) and carboxylic acids: long alkyl-chained EDO-TTF derivative (EDO-TTF-SC18) with acetic acid, and selenium analog of bis(ethlenedithio)tetrathiafulvalene (bis(ethylenedithio)tetraselenafulvalene, BEDO-TSeF) with stearic acid. As well as previous molecular combinations, the MVS formation is brought about by a spontaneous chemical reaction on the water surface. The present results indicate that the reaction proceeds in the wide variety of molecular combinations between EDO-TTF derivatives and fatty acids. Such simple and easy method of the conducting film preparation is useful to obtain ultra thin organic conducting layer which is applicable to molecular-based electronic devices.