Synthesis and Novel Mesomorphic Properties of the Side-Chain Liquid Crystalline Polyacetylenes Containing Phenyl Benzoate Mesogens with Cyano and Methoxy Tails

摘要: The synthesis of side-chain liquid crystalline polyacetylenes containing phenyl benzoate mesogens with octyl spacers and cyano (2a) or methoxy tails (2b) is accomplished, the tuning molecular alignments 2b realized by simple mechanical perturbations. acetylene monomers, 10-[4-(4‘-R-phenoxycarbonyl)phenoxycarbonyl]-1-decynes [R = (1a), (1b)], are prepared two consecutive esterification reactions 10-undecynoic acid. None monomers crystalline, but 1a exhibits an unusual crystal−crystal transition at 70.5 °C, probably due to its strong intermolecular ⋮C−H···N⋮C− hydrogen bonding. polymerizations 1 initiated WCl6−Ph4Sn/dioxane complex yield yellow powdery polymers (2) Mw ca. 30 000, whose structures characterized NMR, IR, UV spectroscopy. mesomorphic behavior 2 investigated DSC, POM, XRD:  2a smecticity in a temperature range as wide over 100 °C (k 80.4 sA 194.8 i), while di...