Novel poly(phenylene vinylenes) with well-defined poly(ε-caprolactone) or polystyrene as lateral substituents: Synthesis and characterization

New macromonomers containing dialdehyde functionalities placed at the middle or at the end of the chains were synthesized in two reaction steps. First, using ring-opening polymerization (ROP) of ε-caprolactone (CL) or atom transfer radical polymerization (ATRP) of styrene (St) in the presence of proper initiators provided well-defined low molecular weight polymers with dibromobenzene moieties. In the second step, using Suzuki couplings of these dibromobenzene functions with 4-formylphenyl boronic acid, macromonomers having 4,4′-dicarbaldehyde terphenyl moieties were obtained. Poly(phenylenevinylene)s (PPVs), with lateral subtituents PSt or PCL chains respectively, were synthesized by following a Wittig polycondensation in combination with bis(triphenylphosphonium) salts in the presence of potassium tert-butoxide. The resulting PPVs were soluble in common organic solvents at room temperature as were the starting macromonomers. All of the starting and intermediate polymers and the final PPVs were characterized by using ¹H and ¹³C NMR, IR, GPC, DSC, and TGA measurements. Optical properties of the polymers were followed by UV and fluorescence spectroscopy. The studied PPVs show a blue or green fluorescence in solution.