NMR studies of polydiacetylenes having alkyl chains. Molecular motions of precursor monomers and the polymers at various stages of the solid-state polymerization

摘要

Polydiacetylenes (PDAs) are synthesized from diacetylenes or more conjugated acetylenes having long chains with specific structures by the solid-state polymerization initiated by gamma-ray, UV or thermal activation. By using solid-state high-resolution C-13-NMR, we studied the molecular motions of the long alkyl chains (n-C14H29) Of the precursor monomers and the polymers for PDAs of a butadiyne (2A), an octatetrayne (4A), a dodecahexayne (6A) and a p-dibutadiynylbenzene (2A-Bz-2A). It is shown that the yields of the solid-state polymerization are related to the molecular motions of the precursor monomers, Since the polymers of 4A and 6A have conjugated acetylenic side chains, further reactions occurred, and the intramolecular rearrangement were also monitored by C-13-NMR. The changes of the C-13 spectra of the alkyl carbons are considered in detail in this paper. (C) 1998 Elsevier Science B.V. [References: 39]