| Abstract: | 1H n.m.r. spectra of the title polymers containing 0%, 57% and 100% cis double bonds and having various degrees of head-tail (HT) bias have been analysed. The olefinic protons give distinct signals for HH, HT and TT trans dyads, also for HT and TT cis dyads, but HH cis dyads are not present in any polymer. The ring protons adjacent to the double bonds also give distinct cis and trans signals as do the methyl protons. The latter give four lines, assigned to cc, ct, tc and tt double bond pairs, and their intensities indicate a somewhat blocky cis/trans distribution for polymers having a high cis content. There is no fine structure which can be positively assigned to ring tacticity effects. |
