Preparation and characterization of 14-[3,6-(didodecyl)-N-carbazolyl]tetradeca-10,12-diynoic acid LB multilayers

An amphiphilic diacetylene monomer containing an alkyl-substituted carbazole side group has been synthesized with the purpose of combining the electronic properties of polydiacetylenes with the charge-transporting properties of carbazole arrays. Langmuir-Blodgett multilayers have been prepared and characterized. The monomer film was polymerized by irradiation at 254 nm. X-ray diffraction revealed the presence of ordered structures with an interlayer spacing of about 63 Å in both the monomer and polymer films. A preferred orientation of the polymeric backbone parallel to the dipping direction was inferred from the dichroic ratio observed in the UV-Vis spectra in polarized light. The relevant anisotropic effect measured in this work is peculiar of this polymer, hence it is probably related to the stiffness of the alkylsubstituted carbazole ring. Investigations with scanning electron microscopy revealed a uniform thickness of the sample with smooth surface and an interlayer spacing in agreement with X-ray results.