DI-ACETYLENIC, PSEUDO-DI-ACETYLENIC AND PSEUDO-TETRA-ACETYLENIC POLYMERS OF PLATINUM - SYNTHESIS, CHARACTERIZATION AND OPTICAL-SPECTRA

Reactions of Me3Sn-C = C-(C = C-)m-C = C-SnMe3 (m = 0, 1) (1, 2), Me3Sn-(C = C)m-p-C6H4-(C = C)m-SnMe3 (m = 1, 2) (3, 4) with the platinum metal halide complexes, [Pt(XnBu3)2Cl2] (where X = P (5), As (6) afford high molecular weight polymeric species, {Pt(XnBu3)2-C = C-(C = C-)m-C = C}n (7-10), and {Pt(PnBu3)2-(C = C)m-p-C6H4-(C = C)m}n (11, 12) in excellent yields. Investigations of the optical absorption and photoluminescence spectra of these complexes show extended pi-electron conjugation through the metal sites on the chain, with a lower pi-pi star energy gap for triacetylenic than for the diacetylenic polymeric complexes. Well-resolved vibronic structure associated with the -C = C-stretching frequency is observed for both absorption and emission, indicating strong electron-phonon coupling for the di- and triacetylenic polymers.