Synthesis of Polyphosphazenes Bearing Covalently Linked Copper Phthalocyanine Units

Soluble poly(organophosphazenes) bearing covalently bound copper phthalocyanine side groups have been synthesized. The synthesis pathway involved the preparation of a high molecular weight poly-[bis(aryloxy)phosphazene] in which 90% of the side groups were phenoxy and 10% were o-dicyanoaryl units. Condensation of this species with a large excess of phthalonitrile, l,2-dimethyl-4,5-dicyanobenzene, 1,2-di-cyano-4,5-bis(phenoxymethyl)benzene, or 4,5-bis[(methoxyethoxy)methyl]-l,2-dicyanobenzene in DMF and in the presence of CuBr yielded open-chain polymers with phthalocyanine side groups covalently linked to the phosphazene chain. On the basis of UV/vis spectral data it was shown that the polymeric phthalocyanines did not aggregate in a variety of solvents. The synthesis of small-molecule, cyclic trimeric model analogues of these polymers has also been accomplished. The solubilities of these small-molecule cyclotriphosphazenyl phthalocyanines are much higher than those of the free phthalocyanines. The electrical conductivities of the iodine-doped trimeric and high-polymeric species, both as compressed pellets and as thin films, were in the range of 10^-4 Ω^-1 cm^-1for the cyclic trimers and 10^-5–10^-8 Ω^-1 cm^-1for the high polymers.