Fused π-conjugated imidazolium liquid crystals: synthesis, self-organization, and fluorescence properties

Abstract

Fused π-conjugated imidazolium compounds bearing two or three long alkoxy chains and various counter anions were systematically prepared following our reported synthetic route.

Liquid crystal ionic self-assembly and anion-selective photoluminescence in discotic azatriphenylenes

“…29 Essentially most iLCs so far reported, possess one or two alkyl tails connected to either a small ionic moiety or a rod-like core, and for most of them, show smectic phases, 17,[32][33][34][35][36][37] with only a few cases displaying columnar phases. 38,39 In contrast, studies of ionic discotic liquid crystals (iDLCs) with a discotic core and displaying columnar mesophases, [40][41][42] are however only just emerging, and only few examples have been reported so far. DLCs with polycyclic aromatic hydrocarbon (PAH) cores [5][6][7][8]10,[12][13][14][15] are indeed of interest since they spontaneously self-organize into columnar mesophases, and possess one-dimensional electronic charge hopping pathway along the molecular columns with fast charge carrier drift mobility.…”

“…Overall, few examples of conjugated core-charged iDLCs with heterocyclic cores containing oxygen, nitrogen or sulfur atoms have been reported. [40][41][42] The synthesis of novel iDLCs is still facing big challenges, as the construction of charged heterocyclic aromatic hydrocar-bons is rendered more difficult by more complex synthetic methodologies based on coupling reactions of variable effi cien-cies, and their extremely tedious purifications. 42 Here, we report a simple molecular design and straightforward synthesis of the azatriphenylene molecular unit, i.e.…”

“…[40][41][42] The synthesis of novel iDLCs is still facing big challenges, as the construction of charged heterocyclic aromatic hydrocar-bons is rendered more difficult by more complex synthetic methodologies based on coupling reactions of variable effi cien-cies, and their extremely tedious purifications. 42 Here, we report a simple molecular design and straightforward synthesis of the azatriphenylene molecular unit, i.e. N-heterocyclic aro-matic, 2, and of the corresponding series of quaternized salts 3 and 4 (Scheme 1) with anions such as Br , I , NO 3 , BF 4 , PF 6 , triflate (CF 3 SO 3 -TfO ), bis(trifluoromethylsulfonyl)-imide (Tf 2 N ), tosylate (TsO ), saccharinate (sac ), D and L camphorsulfate (CS ), alkylsulfonates (C n H 2n+1 SO 3 ), and alkyl-sulfates (C n H 2n+1 SO 4 ).…”

The Fluorescence Behavior Studies and Applications of Two D‐π‐A Type Imidazolium Analogs

“…[10][11][12][13] In addition, imidazolium moiety was an excellent recognition group for some anions or biomolecules that used in fluorescence probes. It has been widely used in constructing the conjugated cationic luminophores.…”

“…Imidazolium moiety possessed the positive charge, and exhibited the strong electron‐withdrawing ability. It has been widely used in constructing the conjugated cationic luminophores . In addition, imidazolium moiety was an excellent recognition group for some anions or biomolecules that used in fluorescence probes .…”