2-DIMENSIONAL ARRANGEMENT OF THIOPHENE - HIGHLY ORDERED STRUCTURES PREPARED BY THE LANGMUIR-BLODGETT TECHNIQUE

3-Thienylpentadecanoic acid was investigated as a Langmuir-Blodgett film-forming molecule at the air-water interface. It shows the typical pressure area isotherms of amphiphilic molecules on a variety of salt-containing subphases. On a Cd2+-containing subphase, the monolayers at the air-water interface were stable at 4-degrees-C for several hours, and the area of 0. 1 9 nm2 per molecule indicates a tight packing of the hydrocarbon chains. To fit in this close packing, the thiophene ring plane must be oriented predominantly perpendicular to the plane of the film. We succeeded in transferring monolayers and multilayers up to several hundred layers onto hydrophobic and hydrophilic substrates. The films were characterised with UV/VIS absorption experiments and with polarisation-dependent Fourier transform infrared absorption spectroscopy. The Langmuir-Blodgett layers show a very high degree of order at the molecular level.