Versatile Synthesis of Soluble Multifunctional Thiophene Copolymers with NLO Activity

Functionalized second-order nonlinear optical (NLO) thiophene copolymers were synthesized. Two elegant syntheses based on the post-functionalization of polymeric precursors obtained by oxidative polymerization were developed, leading to copolymers that proved to be fully soluble in common organic solvents. The new materials were characterized by NMR, FT-IR, and UV-vis spectroscopies, gel permeation chromatography (GPC), and thermogravimetric analysis (TGA). Moreover, the NLO activity of the new materials, as determined by corona poling alignment and second harmonic generation (SHG) measurements, showed a good agreement between the second-order NLO coefficient and the chromophore concentration.