129236-20-0Relevant academic research and scientific papers
Synthesis and liquid crystal properties of a novel homologous series 4-(4′-n-alkoxy benzoyloxy) benzyl benzoates
Patel, Brijesh H.,Doshi
, p. 61 - 69 (2015/10/28)
A novel homologous series consisting of 11 homologues is reported. Liquid crystal properties commence from the hexyloxy homologue and continue up to the tetradecyloxy homologue as enantiotropic nematic mesomorphism only. The rest of the homologues (including hexadecyloxy homologue) are not liquid crystalline. None of the homologues show smectogenic mesophase formation. The texture of the nematic mesophase is of a threaded or Schlieren type. The transition temperatures of the homologues were determined by optical polarizing microscopy equipped with a heating stage. Transition curves of a phase diagram behave in normal manner except for the tetradecyloxy homologue which adopts an unexpected trend of propagation. An odd-even effect is absent for nematic-isotropic transition curve. Analytical and spectral data support the molecular structure of the homologues. The average thermal stability of the series is 78.8°C. Mesomorphic/nematogenic phase length varies from 2.0°C to 13.0°C. The liquid crystal behavior of the present series is compared with structurally similar other known series. Thus, the present series is enantiotropically nematogenic only without exhibition of any smectogenic character with a low melting type, whose mesomorphic phase length is relatively short.
A new series of two-ring-based side chain liquid crystalline polymers: Synthesis and mesophase characterization
Mohan Reddy, Goddeti Siva,Narasimhaswamy, Tanneru,Jayaramudu, Jarugala,Sadiku, Emmanuel Rotimi,Raju, Konduru Mohana,Ray, Suprakas Sinha
, p. 667 - 675 (2013/07/26)
A new series of side chain liquid crystalline polymers containing a core, a butamethylenoxy spacer, ester groups, and terminal alkoxy groups were synthesised and their structures were confirmed. The core was constructed with two phenyl rings and an ester linking unit. All the polymers were characterised by hot-stage polarising optical microscopy, differential scanning calorimetry, variable temperature X-ray diffraction, thermogravimetric analysis, and gel permeation chromato-graphy. The polymers were found to be liquid crystalline. The nematic and smectic A (SA) phases were observed for the homologues with short-terminal chains (C2 and C6), whereas the homologues with longer chains (C8 to C12) exhibited a smectic C phase. The thermal stability of the polymers was found to be in the range of 293 to 326°C and the molecular weights of the polymers were found to vary from 6×103 to 1.3×104.
Molecular Structure and Liquid Crystalline Properties: The Effect of the Terminal Hydroxy Group on Mesomorphic Properties
Sakurai, Y.,Tamatani, A.,Teshima, K.,Kusabayashi, S.,Takenaka, S.
, p. 163 - 172 (2007/10/02)
The thermal properties of 4-hydroxyphenyl 4-(4-alkoxybenzoyloxy)benzoates (1), 4-(4-alkoxyphenoxycarbonyl)phenyl 4-hydroxybenzoates (2), 4-(4-alkoxybenzoyloxy)phenyl 4-hydroxybenzoates (3), 4-hydroxyphenyl 4-(4-alkoxyphenoxycarbonyl)benzoates (4) and some
Thermal and X-Ray Diffraction Studies of Some Liquid Crystals Having a Nitro Group at the Lateral Position
Takenaka, S.,Sakurai, Y.,Takeda, H.,Kusabayashi, S.,Sugiura, H.,Morita, H.
, p. 59 - 70 (2007/10/02)
3-Nitrophenyl 4-(4-octyloxy- and 4-(4-nonyloxybenzoyloxy)-benzoates (compound 1), 4-(4-octyloxyphenoxycarbonyl)phenyl 3-nitrobenzoate (compound 2), 4-(4-octyloxy- and 4-(4-decyloxybenzoyloxy)phenyl 3-nitrobenzoates (compound 3), and 3-nitrophenyl 4-(4-octyloxy- and 4-(4-nonyloxyphenoxycarbonyl)benzoates (compound 4) have been prepared.All the compounds show smectic A and nematic phases, where the molecular arrangement in the smectic A phase is dependent on the orientation of the ester linkages.The smectic A phase for compounds 1 and 3 has a monolayer rearrangement of the molecules, while the smectic A phase for compound 3 also involves a small contribution of a partially bilayer nature near the smectic A-nematic transition.The smectic A phase for compound 2 has a bilayer arrangement, and compounds 4 probably the bilayer one.A dipole correlation within the smectic A phases has been discussed. - Keywords: polar liquid crystals; smectic A modification; x-ray diffraction; lateral substituent effect.
