16331-46-7Relevant articles and documents
Synthesis and Study of Novel Mesogenic Homologous Series: 4-(4′- n -alkoxy benzoyloxy)- n -propyl Cinnamates
Chauhan,Doshi,Sheth
, p. 157 - 165 (2015)
A novel homologous series of liquid crystals viz. 4-(4′-n-alkoxy benzoyloxy) n-propyl cinnamates comprising of 11 homologues has been synthesized. It is a middle ordered melting type of series with exhibition of smectic and nematic mesophases. The first to fifth members of the series are non-mesomorphic. Mesomorphic behavior commences from the sixth homologue. The octyloxy (C8) and decyloxy (C10) homologues are polymesomorphic. The smectic-nematic and nematic-isotropic transition curves behave in a normal manner except for the hexadecyl derivative, which slightly deviates from normal behavior (N-I). An odd-even effect was not observed for the N-I or Sm-N transition curves. The texture of nematic phase is threaded or Schlieren and that of the smectic phase is focal conic fan shaped of the smectic-A type. Transition temperatures and textures of mesophases were observed through an optical polarizing microscope equipped with a heating stage. Thermal stability and mesomorphic characteristics are compared with a structurally related series. Analytical and spectral data support the structure of the molecules.
Mesomorphism and Molecular Structure of Ester Homologous Series Containing Carboxy and Vinyl Carboxy Linking Groups
Chauhan,Doshi
, p. 166 - 175 (2015)
A novel homologous series 4-(4′-n-alkoxy benzoyloxy)-isopentyl cinnamates consisting of eleven homologs is reported. Mesomorphism commences from the hexyloxy homolog up to the hexadecyloxy homolog. The hexyloxy and hexadecyloxy derivatives are only enantiotropically nematogenic while, but the octyl, decyl, dodecyl, and tetradecyl homologs exhibit enantiotropic nematogenic and smectogenic mesophases. The rest of the homologs are nonmesogenic. The textures of nematic phase are threaded or Schlieren and that of the smectic mesophase is focal conic smectic A or C type. The transition curves of the phase diagram behave in a normal manner without the exhibition of an odd-even effect. Analytical and spectral data confirm the molecular structure of the homologs. Overall mesogenic phase temperature range varies from 11.0°C to 59.0°C. The average thermal stabilities of smectic and nematic are 122.25°C and 139.0°C, respectively. The series is predominantly nematogenic and partly smectogenic with a middle-ordered melting type and a considerable range of liquid crystallinity. Melting points and transition temperatures were determined using an optical polarizing microscope equipped with a heating stage. The mesomorphic properties are compared with structurally similar series.
Synthesis and characterization of new nematic liquid crystalline compounds-based thiophene units
Jia, Ying-Gang,Su, Dong,Guo, Zhi-Hao,Hu, Jian-She
, p. 91 - 102 (2016)
Four new liquid crystalline thiophene compounds (M1-M4) with a long flexible spacer were prepared. Their structures were characterized by Fourier transform infrared and proton nuclear magnetic resonance. The mesomorphism and thermal stability were investigated with differential scanning calorimetry, polarizing optical microscopy, and thermogravimetric analysis. The photo-physical properties were evaluated using ultraviolet/visible spectroscopy and photoluminescence. M1-M4 all showed thermotropic mesogenic properties with excellent thermal stability, and exhibited nematic threaded texture, droplet texture, and Schlieren texture on heating and cooling cycles. The effect of flexible spacer and terminal groups on mesomorphic and spectroscopic property is discussed. The experimental results demonstrated that the tendency toward melting temperature (Tm) decreased, while isotropic temperature (Ti) increased with increasing the flexible spacer length. In CHCl3 solution, these thiophene compounds displayed an intense broad absorption band peaking within 230-340 nm and a maximum fluorescent emission wavelength at 426-439 nm.
Mesomorphism dependence on molecular rigidity
Chauhan,Patel,Pandya,Doshi
, p. 47 - 54 (2016)
A novel ester homologous series of thermotropic liquid crystal (LC) has been studied with a view to understanding and establishing the relation between LC property and the molecular structure. The series consists of 11 members, the CCand Cmembers of the series are nonliquid crystals. LC properties commence from the Chomolog and continue up to the Chomolog as enantiotropic nematic and smectic in addition to nematic. Transition temperatures of the homologs were determined by an optical polarizing microscope equipped with a heating stage. Textures of nematic phase are threaded or Schlieren and that of smectic is focal conic of the type-A. Analytical and spectral data confirm the structures of homologs. Thermal stability for nematic is 93 °C and 136°C, respectively. The N-I and Sm-N transition curves of phase diagram do not exhibit odd-even effect. The N-I transition curve partly behaves in an abnormal manner. The Cr-I and Sm-N transition curves behave in normal manner. The LC behavior of the present series is compared with structurally similar known homologous series.
Rh(iii)-Catalyzed three-component cascade annulation to produce theN-oxopropyl chain of isoquinolone derivatives
He, Yuan,Liao, Xian-Zhang,Dong, Lin,Chen, Fen-Er
supporting information, p. 561 - 567 (2021/02/06)
Developing powerful methods to introduce versatile functional groups at theN-substituents of isoquinolone scaffolds is still a great challenge. Herein, we report a novel three-component cascade annulation reaction to efficiently construct theN-oxopropyl chain of isoquinolone derivativesviarhodium(iii)-catalyzed C-H activation/cyclization/nucleophilic attack, with oxazoles used both as the directing group and potential functionalized reagents.
Preparation method of polysubstituted diphenyl ketone
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Paragraph 0054-0057, (2021/09/21)
The preparation method comprises the following steps: (1) a compound represented by the formula II and a compound shown III as a raw material; and synthesizing the compound as shown IV. (2) The compound of Formula IV is subjected to Fries rearrangement to produce a compound of Formula V. (3) A compound of Formula V is subjected to a halogenation reaction in contact with a halogenation reagent to prepare a multi-substituted diphenyl ketone represented by Formula I. Wherein, X is selected from H, F, Cl, Br, I. R1 Selected H from F Cl, Br I are RO selected R from H, C1 - C6. X is selected from F, Cl, Br, and i. The present invention is capable of improving the yield and selectivity of the target product.