Synthesis of a novel [60]fullerene pearl-necklace polymer, poly(4,4 '-carbonylbisphenylene trans-2-[60]fullerenobisacetamide)

A novel [60]fullerene pearl-necklace polymer, poly(4,4'-carbonylbisphenylen e trans-2-[60]fullerenobisacetamide), was synthesized by a direct polyconde nsation of trans-2-[60]fullerenobisacetic acid with 4,4'-diaminobenzophenon e in the presence of large excesses of triphenyl phosphite and pyridine. In the present polymer, [60]fullerene pearls and diamine linkers were attache d to each other by methano-carbonyl connectors. The molecular weight M-w of the polymer was determined to be 4.5 x 10(4) on the basis of the TOF-MS, a nd a GPC analysis of the polymer using polystyrene standards showed a weigh t-average molecular weight of 5.3 x 10(4). The UV-vis spectrum of the resul tant polymer in N,N-dimethylacetamide (DMAc) exhibited a broad absorption ( lambda(max) 310 nm, epsilon 2.1 x 10(4) L.mol(-1).cm(-1)), tailing to longe r wavelengths, and a fluorenscence peak centered at 550 nm was observed in DMAc. There was observed a large downfield-shift of the cyclopropane methyn e proton in the H-1-NMR spectra from 4.57 ppm of the ethyl ester to 5.78 pp m of the polyamide. These observations indicate that the present; polyamide is a high-molecular-weight; [60]fullerene pearl-necklace polymer and that the cyclopropane rings are efficient to make the [60]fullerene cages and th e diamine components conjugatable. (C) 1999 John Wiley & Sons, Inc.