73011-79-7Relevant academic research and scientific papers
Synthesis of aromatic liquid crystals with asymmetric diester based on rod-like multi-ring system by two-step esterification method
Zheng, Min-Yan,Wei, Yong-Sheng,Geng, Wei,Gu, Yuan-Zi
, p. 19 - 27 (2016/07/14)
A novel method of two-step esterifications was developed to synthesize compounds with asymmetric double ester groups. By using this method, six rod-like double ester compounds were prepared with p-hydroxy benzaldehyde, p-hydroxy benzoic acid bicyclohexyl carboxylic acid, cyclohexyl benzoic acid and biphenyl carboxylic acid substituted by n-propyl and n-pentyl as main reactants. The structures and properties of target compounds were confirmed by IR, MS, 1H NMR, elemental analysis, differential scanning calorimetry (DSC) and hot stage polarizing optical microscope (HS-POM). Typical yields of the target molecules were more than 70%. All the molecules have mesophases with the textures of nematic type, indicating a rod-like molecule with a longer rigid skeleton can keep its mesophases. There was no clearing point observed for any of the derivatives before they decomposed so that the temperature ranges of the mesophases could not be determined. The energy differences between frontier molecular orbitals (HOMO-LUMO) (Eg) of the compounds were calculated by cyclic voltammetry (CV). The terminal ring system has an obvious influence on the energy levels and the energy gaps (Eg).
Synthesis of multiring azo-benzoic acid liquid crystalline molecules and their special photosensitive property
Zheng, Min-Yan,Wei, Yong-Sheng,Geng, Wei,Guo, Nai-Ni,Zhang, Ping
, p. 1 - 13 (2015/03/18)
10 new rod-like azo benzoic acid liquid crystals belonged to three series have been prepared, in which trans-cyclohexyl benzene, biphenyl or bi-trans-cyclohexyl carboxylic acid mesogenic cores with ethyl, n-propyl, n-butyl or n-pentyl substituents were connected with azo benzoic acid. Meantime, a simple method was developed in synthesizing compounds bearing both ester and carboxyl groups in one-step reaction. All these compounds have been characterized on the basis of their spectral data, differential scanning calorimeter (DSC) and hot stage polarizing optical microscope (HS-POM). All these compounds have higher thermo-stability. 8 of these compounds have liquid crystalline properties. Their temperature ranges of mesophase have not been obtained, resulting from all the compounds decomposed before their clearing points. Although these compounds are photosensitive in solution under illumination of UV light (365nm), they can't do trans-cis isomerization in their mesophses, indicating the super stabilities of the trans isomer in mesophase.
Multirings aromatic aldehyde liquid crystal with azo linkage and their photosensitivity in mesophase
Zheng, Min-Yan,Wei, Yong-Sheng,Gu, Yuan-Zi,Wang, Shan
, p. 151 - 164 (2014/07/07)
Ten new rod-like aromatic aldehyde liquid crystalline molecules with azo linkage were synthesized, in which bi(trans-cyclohexyl), cyclohexyl phenyl, and biphenyl carboxylic acid mesogenic cores with terminal ethyl, n-propyl, n-butyl, and n-pentyl substituents were esterified with azo benzoic aldehyde. These molecules were designed in an attempt to construct a series of new azo liquid crystalline molecules to investigate the influence of ultraviolet (UV) light on their mesophase. All compounds have been characterized on the basis of their spectral data, differential scanning calorimeter (DSC), and hot stage polarizing optical microscope (HS-POM). All these compounds exhibited liquid crystalline phase that belonged to nematic and photosensitive properties. Their temperature ranges of mesophase are from 101°C to 150°C. Under irradiated 365 nm UV light, they showed photosensitivity in the solvent of methanol. Observed under HS-POM, the UV light also did change the textures of these compounds. The result showed that terminal ethyl is enough for these molecules to exhibit wider temperature range of mesophase, and these new molecules have photosensitivities observed under illumination of UV light not only in solution but also in mesophase due to the change of their structures from trans isomer to cis one.
Mesomorphic compound, liquid crystal composition containing same, liquid crystal device using same and display apparatus
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, (2008/06/13)
A mesomorphic compound represented by the following formula (I): wherein R1 and R2 respectively denote a linear or branched alkyl group having 3-18 carbon atoms capable of including one or non-neighboring two or more methylene groups
Synthesis and Properties of Phenyl Cyclohexyl Ferroelectric Liquid Crystals
Yongmao, Sun,Hongping, Yu,Humin, Zhao,Liangyu, Wang
, p. 87 - 97 (2007/10/02)
In this work, twelve compounds: S(+)-4-4'-(4''-trans-n-alkylcyclohexyl)benzoates; S(+)-4-4'-(4''-trans-n-alkylcyclohexyl)benzoates, where alkyl = C5-C10 were synthesized.The effect of the alkyl c
The Synthesis and Transition Temperatures of Novel Low Molar Mass Cholesteric Materials Derived from (R)-2-(4-Hydroxyphenoxy)propanoic Acid
Booth, Christopher J.,Gray, George W.,Toyne, Kenneth J.,Hardy, Judith
, p. 31 - 58 (2007/10/02)
A comprehensive series of (R)-2-(4-substituted-phenoxy)propanoates and (R)-2-(4-substituted-phenoxy)propanonitriles have been prepared.A wide variety of 4-substituents and ester functions have been examined to determine how the position of the chiral centre affects the cholesteric phase formation in these classes of materials; the synthesis of these novel materials, their transition temperatures and a procedure for assessing their optical purity are described and discussed.Mesogenicity is significantly depressed if the chiral centre is placed centrally within the molecule.
SYNTHESIS OF TRANS-4-ALKYL-1-PHENYLCYCLOHEXANES AND THEIR DERIVATIVES
Bezborodov, V. S.,Bubel', O. N.,Konovalov, V. A.,Ptashnikov, Yu. L.
, p. 1479 - 1483 (2007/10/02)
The alkylation of benzene by 1-alkanoyl-2-chlorocyclohexanes and 1-alkanoyl-1-cyclohexenes leads to the formation of cis- and trans-4-alkanoyl-1-phenylcyclohexanes, the yields of which increase with increase in the reaction temperature. trans-4-Alkyl-1-phenylcyclohexanes were obtained from 4-alkanoyl-1-phenylcyclohexanes and also from the products from the reaction of 4-alkylcyclohexanones with phenylmagnesium bromide.Some mesomorphous derivatives of these hydrocarbons were synthesized.
