Synthesis and characterization of three-arm star-shaped conjugated poly(3-hexylthiophene)s: Impact of the core structure on optical properties

Three-star-shaped conjugated polymers containing poly(3-hexylthiophene) arms and either a triphenylamine or triphenylbenzene core were prepared. The results show the critical role of the core structure on the aggregation of polymers chains and hence optical properties of the star-shaped polymers. Moreover, the star-shaped P3HTs exhibited the lower the Shrinking Factor, g' comparingwith their linear P3HT. Star-shaped molecules consisting of regioregular poly(3-hexylthiophene) (P3HT) chains as the arms, attached to either a propeller-like triphenylamine or a planar triphenylbenzene core, have been synthesized via Suzuki coupling. The structures of the three-arm star-shaped poly(3-hexylthiophene) (s-P3HT) materials obtained were studied using Fourier transform infrared, 1H and 13C NMR, XRD, gel permeation chromatography and DSC. The s-P3HT polymers were soluble in common organic solvents and exhibited number-average molecular weights of 6000-7200gmol-1. Their optical properties in solutions and in solid state films were investigated using the UV-visible absorption and photoluminescence techniques, and were compared with those of linear P3HT. © 2015 Society of Chemical Industry.