Effect of counter ions on the mesogenic ionic N-phenylpyridiniums

Abstract

Two series of ionic liquid crystals (ILCs) derived from N-phenylpyridinium 1–2 were prepared and their mesomorphic properties were investigated.

Ultrathin ionic liquid films on metal surfaces: adsorption, growth, stability and exchange phenomena

“…Ionic liquids (ILs) are a diverse and fascinating class of materials. As salts with comparably low melting pointsoften even below room temperature (RT)they combine typically very low vapor pressures with a large number of tunable chemical and physicochemical properties, depending on the numerous possible pairings of cations and anions [1][2][3][4][5][6][7][8][9][10][11][12][13]. One of the most successful applications involving bulk amounts of ILs is the BASIL TM process for the production of alkoxyphenylphosphines [14,15].…”

Recent synthetic advances in pyridine-based thermotropic mesogens

“…Furthermore, these studies revealed that the stabilities of smectic C and nematic phase increase as the mesogenic core length increases. Wang et al 44 synthesized two series of ionic liquid crystals, i.e. N-phenylpyridinium derivatives (98)(99)(100)(101)(102)(103)(104).…”

“…Smectic A phase with a homeotropic texture or focal conic texture was generally observed during the cooling cycle. Powder XRD studies also revealed that smectic A phases exist as monolayer structures for 136-141 or bilayer structures for 135a-c. Further, the melting temperatures (T mp ) remained at T mp ¼ 88. based mesogens with pyridinium-based mesogens (literature from Wang et al 44 ) and found that the bipyridinium-based mesogens exhibited wider DT SmA ranges and higher T cl values than the pyridinium-based mesogens. Decomposition before the clearing point was observed in the ionic salts with small anionic moieties, i.e.…”

Liquid Crystals Based on the N-Phenylpyridinium Cation—Mesomorphism and the Effect of the Anion

“…Recently, we reported the synthesis and mesomorphism of some polycatenar ionic mesogens based on N -phenylpyridinium triflates [ 15 ], noting related studies on calamitic N -phenylpyridinium salts [ 8 , 16 ] and some wedge-shaped N -phenylpyridium salts [ 17 ] by Lai et al The study was prompted both by a wish to compare truly ionic polycatenar mesogens with the polycatenar stilbazole silver(I) salts that we had reported over several years, and also to investigate how the different driving forces for mesophase formation between ionic mesogens (electrostatics) and polycatenar systems (chain/core interfaces and volumes) may be accommodated simultaneously. The study has since been extended to salts with different anions, the results of which are now reported.…”