Poly(pyridinium salt)s with organic counterions derived from an aromatic diamine containing tetraoxyethylene units exhibiting amphotropic liquid-crystalline and photoluminescence properties
Several poly(pyridinium salt)s containing various organic counterions and tetraoxyethylene units in their backbones were synthesized by either ring-transmutation polymerization reaction of 4, 4'-(1, 4-phenylene)- bis(2, 6-diphenylpyrylium tosylate) with bis(2-(2-(4-aminophenoxy)ethoxy)ethyl) ether on heating in dimethyl sulfoxide or metathesis reaction of the tosylate polymer with the corresponding lithium or sodium salts in acetonitrile. Their chemical structures were determined by 1H-NMR and 13C-NMR spectroscopy, and elemental analyses. Their number-average molecular weights and polydispersity indices were in the range of 34, 000-52, 000 and 1.14-1.38, respectively, as determined by gel permeation chromatography. They were characterized both for their thermotropic and lyotropic liquid-crystalline properties by using differential scanning calorimetry and polarizing optical microscopy. As these polymers exhibited liquid-crystalline phase both in the melt and in solutions, they are classified as an amphotropic class of ionic polymers. Their light-emitting properties in a large number of organic solvents that ranged from nonpolar to polar solvents and in films cast from methanol and acetonitrile were also studied by using spectrofluorometry. © 2009 Wiley Periodicals, Inc.