Synthesis and Optical Properties of Soluble Conjugated Poly(p-Diethynylbenzene)s

A series of novel poly(p-diethynylbenzene)s (PDB) has been prepared by the oxygen-coupling polycondensaton of aryl acetylenes, for the first time. Different side chains including n-decyloxy, n-oclyl, methoxy, and methyl groups were attached to the rigid-rod polymer main chain in order to change the band gap of the polymer. The polymers have good solubility in organic solvents and narrow MWD (∼1.5). Like poly(p-phenyleneethynylene)s (PPEs), poly(p-diethynylbenzene)s (PDBs) have high photoluminescence in solution and the solid state. The photoluminescence quantum yields of PDBs are can reach 12.5%. The studies of UV and photoluminescence indicate that aggregation and intermolecular interactions influence the photophysical properties. The electrochemical study showed the polymers have a good electron-accepting property (Eox = l.l∼1.4 V vs SEC) induced by the electron-withdrawing effect of the triple bonds.