Investigation on different procedures in the oxidative copolymerization of a dye-functionalized thiophene with 3-hexylthiophene

For the purpose of preparing materials for nonlinear optics applications, a 3-ethylthiophene bearing an NLO-active chromophoric group as a substituent at the end of the ethylic chain was copolymerized with 3-hexylthiophene. Different FeCl3-based oxidative polymerization conditions in solvents such as CH3NO2 and CCl4 and their effects on the copolymers characteristics and solubility in CHCl3 (i.e., the copolymer's soluble fraction) were examined. This work allowed to achieve a satisfactory chloroform-soluble fraction of the copolymer, still containing a notable amount of NLO-active group, and to tune to some extent the main characteristics of the copolymer; moreover, the behavior of the monomers−solvent−oxidant system was investigated.