Synthesis and characterization of 3-hexyl multisubstituted thienylene-phenylene polyazomethines

The synthesis and characterization of the series of polymers constituted by the periodic alternation of thienylenic and phenylenic moieties linked by azomethines groups are reported. The chemical structures were determined by H-1 NMR, FT-IR, mass, and GPC analyses; while the electronic properties in the neutral state were studied by UV-vis spectroscopy in both solution and the solid state. Thermal characterizations, performed on the polymer series, using TG and DSC analyses indicated stability up to 400 degrees C and no melting point also due to a postpolymerization process. The solid-state aggregation was investigated by XRD spectroscopy, revealing for the six-thienylenic-ring term a semicrystalline arrangement, after a proper annealing together with a nematic mesophase at temperatures higher than 180 degrees C.