Poly(pyridinium salt)s with organic counterions derived from 3,3′-dimethylnaphthidine: thermal, liquid crystalline, and optical properties

Poly(Pyridinium Salt)s Containing 2,7-Diamino-9,9′-Dioctylfluorene Moieties with Various Organic Counterions Exhibiting Both Lyotropic Liquid-Crystalline and Light-Emitting Properties

“…Compared with their solutions spectra, their λ em peaks were found to exhibit hypsochromic (blue) shifts of 25, 38, 47, and 35 nm, respectively. The emission properties may be attributed to the fact that less ordered structures were built up during the film formation resulting in less π-π stacking in the solid-state of these polymers, which are in excellent agreements with the previously reported of this class of poly(pyridinium salt)s [4][5][6][7][9][10][11][16][17][18][19][20][21][22]. The blue shifts in these polymers, as opposed to red shifts in π-conjugated polymers including π-conjugated polyelectrolytes of ordered structures, may be related to the fact that the extensive face-to-face π-π stacking phenomena of aromatic moieties do not occur in these poly(pyridinium salt)s that lead to less ordered structures presumably because of repulsive interactions of positive charges in the backbones of the polymer chains.…”

“…Much of this behavior may be understood in terms of supramolecular hairy-rod type polymers [ 12 , 13 , 14 ]. Additionally, π-conjugated, and even non-conjugated ionic polymers exhibit lyotropic LC phases in both protic and aprotic solvents and light-emitting properties in both solution and solid-state depending on their chemical microstructures [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ]. They can be appropriately called functional ionic polymers as delineated (vide infra).…”

Over one century after discovery: pyrylium salt chemistry emerging as a powerful approach for the construction of complex macrocycles and metallo-supramolecules

“…Through the facile polymerization process by condensation reactions between bis-pyrylium salts and primary diamines, a variety of cationic pyridinium polymers were synthesized and simply purified by precipitation and washing. 11,12 Benefiting from their positive charges on the backbones and the aromatic structures, such poly(pyridinium salt)s 13,14 have displayed magnificent features, such as electrochromism 15,16 , photochromism 17 , thermochromism 18 , liquid-crystalline 19,20 and sensitive DNA detectability 21,22 , and attracted numerous attention in the fields of chemistry, physics and biology.…”