113840-33-8Relevant academic research and scientific papers
The synthesis, mesomorphic and dielectric investigation of new unsymmetrical bent-core mesogens derived from 3-hydroxybenzoic acid
Ocak, Hale,Ahlatc?o?lu ?zerol, Esma,?elikel, Fulya ?a?la,Okutan, Mustafa,Bilgin Eran, Belk?z
, p. 3899 - 3911 (2020/05/26)
Abstract: The synthesis, mesomorphic and dielectric investigation of new unsymmetrical bent-core mesogens derived from 3-hydroxybenzoic acid central core with linked two rodlike units carrying (S)-3,7-dimethyloctyloxy group and an n-alkyloxy chain at both terminals are presented. The liquid crystalline properties of the new unsymmetrical bent-core materials have been investigated by polarizing optical microscopy and differential scanning calorimetry. New compounds with the reversed ester linking unit exhibit a monotropic or enantiotropic columnar mesophase at lower temperatures as compared to analogs with a straight chain depending on the presence of the branched (S)-3,7-dimethyloctyloxy terminal chain. Dielectric measurements for one of the bent-core mesogens, 3-[[4-[[4-(octyloxy)benzoyl]oxy]benzoyl]oxy]benzoic acid 4-[[4-((S)-3,7-dimethyloctyloxy)phenoxy]carbonyl]phenyl ester (OBDPE), have been carried out on the angular frequency range from 25.12 to 50265k?rad/s at different temperatures. Thanks to dielectric measurements, real and imaginary dielectric constant, conductivity mechanism and dielectric relaxation mechanism of OBDPE were obtained. Graphic abstract: [Figure not available: see fulltext.].
New chalcone based liquid crystals with allylidene amino linking unit: Synthesis and characterization
Sharma, Vinay S.,Sharma, Anuj S.,Jadeja, Upendra H.,Suthar, Deepak
, p. 64 - 81 (2019/02/24)
In this study, the synthesis, structural characterization and mesomorphic properties of newly thirteen calamitic shaped compounds derived from allylidene amino chalcone and 4-n-alkoxy benzoyloxy benzoic acid. Comp.H1 to H3 exhibited nonliquid crystalline nature, while comp.H4 to comp.H18 displayed enantiotropical smectic C phase. Phase transition temperatures of present synthesised compounds were determined by optical polarising microscopy (POM), differential scanning calorimetric (DSC) and powder X-ray diffraction (PXRD) techniques. Thermal stabilities of smectic to isotropic phase are 150.0 °C and temperature range of mesophase is in decreasing order from comp.H3 to comp.H18 respectively. The presences of SmC phase are the type of broken fan and needle type in present synthesized series. It is also shown that presence of chalcone amino allylidene central linking group favors a calamitic liquid crystalline behaviour in molecules with lower member to higher member aliphatic side chain in alkoxy group (-OR).
New hockey stick shaped amino allylidene (?N?CH?CH?CH) based compounds: Effect of linkage group on mesomorphic properties
Sharma, Vinay. S.,Vekariya, Rajesh. H.,Sharma, Anuj. S.,Patel
, p. 84 - 98 (2017/09/25)
Two nonlinear hockey stick shaped homologous series based on three linking groups have been synthesized and characterized by elemental analyses and spectroscopic techniques. The mesomorphic properties of these compounds were observed by polarizing optical microscopy (POM) and differential scanning calorimetry (DSC). In this present investigation, we have synthesized two homologous series viz. 2-((3-phenyl allylidene) amino) phenyl 4-((4-n-alkoxy benzylidene) amino) benzoate (series-1) and 4-((2-((3-phenyl allylidene) amino) phenoxy) carbonyl) phenyl-4-n-alkoxy benzoate (series-2). Both the series are differing with respect to first linking group. In series-1, comp.C4-C18 shows nematic as well as smectic phase while in series-2, comp.C10-C16 shows smectic and nematic phase while comp.C4-C18 shows only nematic phase.
Synthesis and mesomorphic properties of calamitic shaped molecules with chalconyl-ester and lateral fluoro substituents
Sharma, Vinay S.,Sharma, Anuj S.,Vekariya, Rajesh H.,Patel
, p. 32 - 44 (2018/03/21)
In this study we have synthesized a new class of compounds incorporating of chalcones and laterally substituted fluoro group. A series of new chalcones with five aromatic rings is synthesized and characterised by elemental analyses and spectroscopic techniques such as Fourier transform infrared [FT-IR] and proton magnetic resonance magnetic resonance [1H NMR] spectroscopy. The mesomorphic properties of these compounds were observed by optical polarized light microscopy (POM) and confirmed by differential scanning calorimetry (DSC). It is found that all the prepared materials display enantiotropic LCs phases except first three homologue in present series. The lower homologues (n = 4 to 12) display SmC and nematic phase while, in higher homologues (n = 14 to 18) only SmC phase were seen in heating and cooling condition.
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.
BENT-CORE LC DECORATED GOLD NANOCLUSTERS
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, (2011/04/18)
Novel thiol-terminated bent-core liquid crystals (LCs) are used to decorate gold nanoparticles. Thioacetate or xanthate/xanthogenate functional groups are used to effect the attachment of the LCs to the gold nanoparticles. Such bent-core decorated nanoparticles may be dissolved in bent-core liquid crystal host media to provide polarizable systems which respond quickly to applied electric fields and exhibit other interesting and useful optical and electro-optic behaviour.
Synthesis and characterization of symmetrical eight aromatic ring containing bent-shaped material derived from benzophenone
Majumdar,Ghosh,Chakravorty
, p. 63 - 72 (2011/09/13)
A new family of symmetrical eight aromatic ring-containing bent-shaped mesogens in which the central elbow is a ketone has been synthesized and characterized. The effect of the side chain on the mesomorphism has been studied. All the bent derivatives were found to exhibit mesomorphism. The higher homologues of the series exhibit the B1 phase and the lower homologues of the series show the B6 phase. Copyright Taylor & Francis Group, LLC.
Chiral smectic *C mesogens having ester and amide central linkages
Tandel,Vora
, p. 103 - 116 (2008/09/20)
Ten members of a chiral homologous series 4-(4'-n-alkoxy benzoyloxy benzoyl)4''- S- (+) 2-methyl butoxy anilides were synthesized in multiple step synthesis. Series exhibits chiral smectic *C and cholesteric mesophases. In this series, n-propyl to n-dodecyl derivatives exhibit smectic *C and cholesteric mesophases. n-Tetradecyl and n-hexadecyl derivatives exhibit only smectic *C phases. The plot of transition temperatures versus number of carbon atoms in alkoxy chain exhibits odd-even effect for cholestric-isotropic transition temperatures. The effect of amide linkage and chirality is discussed in detail. High-temperature cholestric phases exhibit vivid colors. Two compounds were analyzed by calorimetric study (C12 and C14) to confirm the transition temperatures of which was observed under polarizing microscope. The mesogenic behavior of the series compared with other series where amide central linkage differs in its position. The mesogenic thermal stability is compared with other related homologous series. The result indicates that amide linkage enhances smectic as well as cholesteric thermal stability but enhancement in smectic phase is much higher. Compounds are characterized by elemental analysis, IR spectral data, Mass spectral data, DSC, NMR, and microscopic study.
Bent-core liquid crystal (LC) decorated gold nanoclusters: Synthesis, self-assembly, and effects in mixtures with bent-core LC hosts
Marx, Vanessa M.,Girgis, Hidy,Heiney, Paul A.,Hegmann, Torsten
supporting information; experimental part, p. 2983 - 2994 (2010/02/27)
We present the first synthesis of a series of thiol-, thioacetate-, and xanthate-terminated bent-core derivatives, as well as the preparation of gold nanoclusters using the thiol-terminated bent-core compounds. The mesomorphic properties of the bent-core compounds have been investigated by polarizing optical microscopy (POM), differential scanning calorimetry (DSC), small angle X-ray scattering (SAXS), and electro-optic tests. From this series, the mono-xanthate derivatives form rectangular or hexagonal columnar phases, and the mono-thiol derivative with shorter alkyl chains forms a metastable, likely smectic, phase. All other bent-core compounds and intermediates exclusively form disordered or multi-layer lamellar crystalline solid modifications. High-resolution transmission electron microscopy (HR-TEM) images of the bent-core functionalized gold nanoclusters prepared from the thiol-terminated derivatives, taken after slow evaporation of the solvent, provide evidence for the formation of self-assembled nanocluster arrays. Upon dispersion of these gold nanoclusters in two structurally related bent-core LC hosts (one forming a SmCPA, and the second with a terminal double bond displaying a Colr phase), a shift in the surface plasmon resonance was observed indicating a LC host-dependent aggregation of the nanoparticles. Finally, we report initial results on the effects of different concentrations of these nanoclusters on the thermal properties as well as the applied voltage/current response of the parent SmCPA host.
Symmetric bent-core mesogens with m-carborane and adamantane as the central units
Pociecha, Damian,Ohta, Kiminori,Januszko, Adam,Kaszynski, Piotr,Endo, Yasuyuki
supporting information; experimental part, p. 2978 - 2982 (2010/03/26)
Several members of two homologous series of symmetric bent-shaped compounds with either m-carborane or adamantane (1[n] or 2[n], n = 9-13) in the central position were synthesized and investigated by optical, calorimetric, X-ray diffraction, and electro-o
