BEHAVIOR OF BIS(ALKYLTHIO)TETRATHIAFULVALENE DERIVATIVES OF LANGMUIR-BLODGETT-FILMS UPON IODINE EXPOSURE

New bis(alkylthio)tetrathiafulvalene (BEDTTTF) derivatives, possessing a strong amphiphilic character, have been synthesized with the goal of building Langmuir-Blodgett (LB) films. Their ability to function as building blocks for conducting LB films is discussed. The films initially appear to be insulating but undergo major (reversible) changes upon exposure to iodine vapor. Their behavior is followed by IR spectroscopy, and small-angle X-ray scattering experiments, before, during, and after iodination. Upon being exposed to iodine vapor, one of these films exhibits transient conducting behavior which was monitored with IR spectroscopy. The appearance of an entirely new phase was also checked by X-ray low-angle measurements. Moreover, this conducting state appears to be built through an intermediate dimer formation step. These results are discussed in the framework of redox potential and reaction speed and in connection with molecular geometry of the brick stone components.