Thermotropic Liquid Crystalline Polymers Having Five-Membered Heterocycles as Mesogens, 7. Synthesis and Photoluminescent Properties of Semi-Rigid Thermotropic Liquid Crystalline Polyesters Based on a Quaterphenyl Analog of 2,2′-Bis(1,3,4-thiadiazole)

Synthesis and Properties of Liquid-Crystalline Semi-Rigid Polyesters Based on Isophthalates of Nitro- or Methoxyazobenzene and Dioxydiundecanols of Biphenyl or 2,5-Diphenyl-1,3,4-Thiadiazole

“…[24] We also reported that semi-rigid polyesters containing terphenyl analogue of 1,3,4-thiadiazole (2,5-diphenyl-1,3,4-thiadiazole) and the quaterphenyl analogue of 2,29-bi-1,3,4-thiadiazole in the main chain display thermotropic LC phases and emit blue and bluish green light in the solid states. [17,23,24] These facts led us to build up new multifunctional polymers composed of both azobenzene units in the side chain and calamitic mesogens in the main chain and to investigate their properties. They are expected to not only form thermotropic LC phases, but also show PL and EL properties.…”

“…atom instead of sulfur atom and being electron-transporting materials for electroluminescent (EL) devices, show interesting optical properties together with the LC properties. [17,23,24] Recently we found that thermotropic LC quaterphenyl analogues constituted of central 2,29-bi-1,3,4-thiadiazole ring exhibit EL spectrum with blue-emission. [24] We also reported that semi-rigid polyesters containing terphenyl analogue of 1,3,4-thiadiazole (2,5-diphenyl-1,3,4-thiadiazole) and the quaterphenyl analogue of 2,29-bi-1,3,4-thiadiazole in the main chain display thermotropic LC phases and emit blue and bluish green light in the solid states.…”

Preparation and properties of novel thermotropic liquid crystalline hyperbranched polyesters composed of five‐membered heterocyclic mesogen by A2 + B3 approach

“…Mochizuki et al found that linear LC polymers having 1,3,4‐oxadiazole units in the side chain emit fluorescent light and can be used as materials for the organic EL devices 19. Our previous papers described on synthesis of a series of linear polyesters comprising the 1,3,4‐thiadiazole ring as mesogens in the main chain, which display both the LC and PL properties, but their quantum efficiencies were low and the optical properties were found to be improved 20–26…”

Liquid crystalline homopolyesters having main chain calamitic mesogens and one or two side chain azobenzene moieties in the repeat units

“…We have also prepared a series of semi-rigid polyesters containing various aromatic derivatives of 1,3,4-thiadiazole (biphenyl [22,23], terphenyl [24,25], quarterphenyl [26,27], quinquephenyl [28] and distyrylbezene analogues [29]) in the main chain, and discovered that they show thermotropic LC properties arising from the good mesogenicity of aromatic 1,3,4-thiadiazole units, even though they have bent molecular structures (160 ‡).…”

“…Experimental 2.1. Characterization FTIR and 1 H NMR spectra were recorded as described previously [20][21][22][23][24][25][26][27][28][29]. DSC measurements, optical texture observations, X-ray diffraction (XRD) and molecular weight measurements by size exclusion chromatography (SEC) were carried out according to previously published procedures [20][21][22][23][24][25][26][27][28][29] …”