Abstract:

Poly(p-phenylene ethylene)s containing laterally attached push-pull unit were synthesized by Sonogashira coupling reaction in the presence of different Pd catalysts（Pd(PPh₃)₄ and PdCl₂(PPh₃)₂,PPh:P(C₆H₅)₃). The structures and properties of the intermediate were identified by elemental analysis, IR, NMR, and so on. The polymers are soluble in common organic solvents and exhibits blue fluorescence. It has been found that the polymers prepared in the presence of different Pd catalysts have similar molecular mass and optical properties. The fact that the absorption maximum wavelength and emission maximum wavelength do not chang with the increase of the concentration of the polymers implies the electrostatic repulsion among the side chains can restrain the formation of aggregates. The optical study of the solid film of the polymers has supported the result.

Key words: Poly (p-phenylene ethynylene), aggregates, dipolar unit.