MIXED LANGMUIR-BLODGETT-FILM BASED ON TETRAKIS(HEXADECYLTHIO) TETRATHIAFULVALENE WITH STEARIC-ACID

A new TTF derivative tetrakis(hexadecylthio)-tetrathiafuivalene (THT-T TF) as a Langmuir-Blodgett film material is synthesized. The molecular behavior at the air-water interface is studied by admixture different molar numbers of stearic acid (SA) and a possible molecular reorganiz ation is discussed according to the occupied area per THT-TTF molecule at different SA molar numbers. THT-TTF molecules form dimers, monolay er and intermediate. The ultraviolet (UV) spectra prove this point qua ntitatively. After iodine oxidation, THT-TTF is not oxidized completel y to the cation radical THT-TTF+ from Raman spectra. The formation of triiodide chains has been proved by Raman spectra and UV absorption sp ectra. Intercalation of the triiodide chain in the bilayers induces th e alkyl chains rearrangement and a large reduction in layer thickness. The investigation of conductivities shows that the conductivities are proportional to the THT-TTF molar fraction and that there is a small percolation threshold at PHI = 0.50, which means that THT-TTF is a 2D molecular system. The maximum conductivity reaches 0.9 S cm-1.