Novel Macromolecular Materials for Electronic and Optical Applications

摘要

A series of thiophene containing poly(arylene ethynylene) have been synthesizedand their molecular structures and PL properties have been characterized. A convenient synthetic route has been developed to prepare bis(3-alkylthienyl)ethyne (5) in high yield. Various attempts have been made to use (5) as an essential building block for developing novel poly(arylene ethynylene) materials. Regioregular poly(3-hexyl-2,5-thienylene ethynylene) (P3HTE) have been synthesized inorder to compare the steric interaction in the corresponding polymers. Asystematic study has been carried out to evaluate the regioregularity effect of the polymer structure on the PL properties. P3HTE of a head-to-tail chain sequence showed stronger PL intensity than the corresponding polymer with a head-to-head chain sequence, although they exhibit the essentially same absorbance. The quantum efficiency of P3HTEs were found to increase sharply with the conjugation length of themolecules when the chain length is shorter than the tetramer. Further extending the conjugation length beyond the tetramer appeared to shift the fluorescence emission band to a longer wavelength, but to have little effect on the quantum efficiency of the molecule. Several alternating