C. Pugh, V. Percec
Feb 1, 1990
Citations
0
Influential Citations
15
Citations
Journal
Polymer Bulletin
Abstract
Summary1,4-Bis[2-(4′,4″-diheptyloxyphenyl)ethynyl]benzene and 1,4-bis[2-(3′,3″-dimethyl-4′,4″-diheptyloxyphenyl)ethynyl]benzene were synthesized by a one pot phase transfer Pd(O)/Cu(I) catalyzed three step coupling of 1,4-diiodobenzene with 2-methyl-3-butyn-2-ol and the appropriate aryl halide. Both compounds display mesomorphic behavior similar to that of the analogous 1,2-(4,4′-dialkoxyaryl)acetylenes, except that the temperature window of each phase is stabilized, such that an enantiotropic mesophase is even observed in the derivative containing a methyl branch in the mesogen. Both compounds form mesomorphic EDA complexes with p-chloranil as electron acceptor, and display a depression of the nematic-isotropic transition temperature.