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 FeCl<INF>3</INF>-based oxidative polymerization conditions in solvents such as CH<INF>3</INF>NO<INF>2</INF> and CCl<INF>4</INF> and their effects on the copolymers characteristics and solubility in CHCl<INF>3</INF> (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.