39649-71-3Relevant articles and documents
Anhydrous proton conduction in liquid crystals containing benzimidazole moieties
Tan, Shuai,Wei, Bingzhuo,Liang, Ting,Yang, Xiaohui,Wu, Yong
, p. 34038 - 34042 (2016)
A homologous series of biphenyl benzoate-based compounds with an alkthio chain bearing a benzimidazole moiety at the termini was synthesized by a nucleophilic substitution reaction. The compounds exhibited smectic A and nematic phases over a temperature range of 173-116 °C during the cooling process. A partially interdigitated bilayer order developed in the smectic assemblies and hydrogen-bonding between the benzimidazole moieties extended along the plane parallel to the smectic layer. Electrochemical characterization revealed that the liquid crystal phases favoured anhydrous proton conduction in the benzimidazole compounds and a proton conductivity of 4.4 × 10-5 S cm-1 was achieved at 173 °C. The temperature dependence of the proton conductivities approximately followed the Arrhenius law and the proton conduction in the benzimidazole liquid crystals was assumed to be dominated by the proton hopping mechanism.
Development of tribenzamide functionalized electrochemical sensor for femtomolar level sensing of multiple inorganic water pollutants
Ashiq, Muhammad Naeem,Kokab, Tayyaba,Manzoor, Alia,Nisar, Jan,Shah, Aamir Hassan,Shah, Afzal,Siddiqi, Humaira Masood
, (2020)
A novel tribenzamides derivative N-{4-[2-(1,3-Benzoxazolyl)]phenyl}-3,5-N,N′-bis(4-hexyloxybenzoyl)benzamide (BOC6), containing three amide groups, was successfully synthesized and characterized through multiple spectroscopy techniques. The ultrasensitive electrochemical platform was developed by fabrication of glassy carbon electrode (GCE) with synthesized multifunctional tribenzamide appended BOC6 for the removal of water pollutants. The performance of the engineered sensor was studied by its electrochemical characterization with cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and square wave anodic stripping voltammetry (SWASV). The modifier played a facilitating role between the GCE surface and the target metal ions by bringing analytes closer to transducer surface resulting in appearance of intense electrochemical signals. Under pre-defined optimized conditions of SWASV, the BOC6 modified electrode was able to attain distinct oxidative current signals of thallium, arsenic, and mercuric ions simultaneously in one voltammogram scan. The sharp electrochemical signal and peak potential shift of thallium (Tl), arsenic (As) and mercury (Hg) oxidation at ?0.79 V, ?0.06 V and 0.22 V respectively, versus reference electrode Ag/AgCl evidence the electrocatalytic role of BOC6/GCE as compared to bare GCE at ?0.68 V, ?0.01 V and 0.3 V, respectively. Moreover, it was found to sense femtomolar concentration of aforementioned toxic ions, much lower than the world health organization (WHO) and environmental protection agency (EPA) guidelines for drinking water [1]. The limit of detections (LODs) obtained on for Tl(I), As(III), and Hg(II) detection were 2.19 fM, 1.97 fM, and 2.52 fM, respectively. Conclusively, the designed electrode was portable, cost effective, resistant to the interference species, highly stable and gives repeatable and reproducible voltammograms of analytes via strong interactions with target ions even in real water samples.
Synthesis and characterization of novel rod-like ester-based liquid crystalline homologous series: Effect of tert-butyl tail on mesomorphism
Thakur, Shavi,Patel, Hemant N.
, p. 76 - 89 (2021/04/14)
A new rod-like homologous series consisting twelve compounds with central ester linkage and terminal tert-butyl group, tert-butyl [4-(4’-n-alkoxybenzoyloxy)benzoates] has been synthesized and characterized through standard spectroscopic techniques like UV, FT-IR, 1HNMR, DSC, POM, and XRD. Methoxy and ethoxy derivatives are nonmesogenic. Nematic mesophase commences as enantiotropy from propyloxy derivative and persists up to the octadecyloxy derivatives. Smectic A mesophase commences as monotropy from propyloxy to the octadecyloxy derivatives. The mesomorphic properties of present series are compared with other structurally related series to evaluate the effect of terminal tert-butyl group on mesomorphism. Two derivatives are subjected to in?vitro antimicrobial activity.
Dependence of mesomorphism on terminal polar group in novel azoester series
Kher, Seema N.,Prajapati,Makwana,Chandra, Raviprakash S.
, p. 44 - 53 (2019/10/14)
Novel homologous series 4-(4′-n-alkoxy benzoyloxy) napthyl azo 4″–bromo benzenes, consisted of 11 members of a series. All the 11 members (ethoxy to hexadecyloxy) except hexadecyloxy are only enantiotropically nematogenic without exhibition of any smectogenic character. Transition temperatures and the textures are determined by an optical polarizing microscopy equipped with a heating stage. Textures of a nematic phase are threaded or schlieren. Analytical and spectral data supported the molecular structure of homologs. Transition curves viz., solid-nematic and nematic-isotropic showing phase behavior of the mesophase in a phase diagram behave in normal manner. Alternation of transition temperatures is exhibited by N–I transition curve. Thus, novel series is entirely nematogenic and high ordered melting type. Thus, synthesis of a novel azoester homologous series is carried out with a view to understand and establish the effect of molecular structure on Liquid crystal (LC) behaviors of a substance.
Study of Y-shaped liquid crystalline materials with polar nitro substituent
Dixit, Sandhya
, p. 77 - 84 (2018/06/27)
A new homologous series of Y-shaped liquid crystals namely 4-Nitro-[2′4′bis (4″-n-alkoxybenzoyloxy)] phenyl bisazobenzenes have been synthesized and its thermotropic properties studied on the hot stage of a polarizing microscope. The compounds consist four phenyl rings joined through ester and bisazo linkages with alkoxy and nitro as terminal substituents. The structures of synthesized compounds were confirmed by spectroscopic techniques such as FTIR, 1HNMR as well as elemental analysis. The compounds were found to exhibit enantiotropic nematic and smectic mesophases. The role of molecular shape, size and polarity of functional groups in the mesophases formation is discussed.
Design and characterization of novel bis-benzamide liquid crystalline materials
Iqbal, Asma,Siddiqi, Humaira Masood,Akhter, Zareen,Qaiser Fatmi, Muhammad
, p. 135 - 141 (2017/09/23)
A new homologous series of symmetric, bent-shaped bis-benzamide dimers have been prepared. Several 1,n-bis(p-aminophenoxy)alkanes (n = 3, 5, 9,10,11) were employed as spacers and p-hexyloxy tails have been synthesized and appended to the spacers by amide linking groups. Different important parameters were explored using computational analysis by semi empirical method. The experimental results were correlated with theoretical studies and relationship between molecular structure and mesogenic behavior has been established. The mesomorphic properties of the resultant dimers were characterized by differential scanning calorimetry (DSC) and polarized optical microscopy (POM) equipped with a hot stage. Change in mesomorphic properties with change of methylene spacers was observed. Enantiotropic mesogenic behavior was exhibited by D3A6, D10A6 and D11A6 and the needle like and blurred schleiren textures were observed. It was observed that increased methylene spacers chain length decreased the melting temperatures. Thermogravimetric analysis revealed the thermal stability of dimers upto 360 °C.
Mesomorphism dependence on terminal polar group in the nonlinear novel azoester series
Kher, Seema N.,Prajapati,Chandra, Raviprakash S.,Makwana
, p. 1 - 9 (2019/02/24)
Synthesis of a novel azoester homologous series is carried out with a view to understand and establish the effect of molecular structure on liquid crystal (LC) behaviors of a substance. Novel series consists of ten LC substances. All the homologs are enantiotropically nematogenic without exhibition of smectic property. Transition and melting temperatures, textures of LC are determined by an optical polarizing microscopy equipped with a heating stage. Textures of nematic phase are threaded or schlieren. Transition curves of a phase diagram behaved in normal manner. Nematic–isotropic transition curve exhibited odd–even effect. Analytical and spectral data supported and confirmed the structures of homologues.
Dependence of mesomorphism on geometrical shapes of isomeric and nonisomeric series of chalconyl esters
Patel, Priya K.,Shah
, p. 168 - 177 (2017/03/08)
A meta substituted chalconyl ester homologous series: RO?C6H4?COO?C6H4(meta)?CO?CH?CH?C6H4?OC12H25(n)(para) is synthesized and studied with a view to understanding the effect of molecular substitution at meta position in a molecular structure on thermotropic liquid crystal properties. The novel homologous series consists of thirteen homologues (C1 to C18). All the homologues except the nonliquid crystal homologues C1, C2, C3 are enantiotropic nematic with the absence of smectic properties. The transition and melting temperatures were determined by an optical polarizing microscopy (POM) equipped with a heating stage. Textures of a nematic phase are threaded or Schlieren. Transition curves (Cr-N/I and N-I) behave in normal manner except homologues between C10 and C14 of N-I curve, which show negligible deviation from normal and a smooth descending tendency. The N-I transition curve exhibits an odd-even effect up to C10 homologue and then the odd-even effect disappears for higher homologues. Analytical and the spectral data support the molecular structures. Thermal stability for nematic is 107.3°C and the mesophase lengths range between 13.0°C and 35.0°C at the C18 and C12 homologues respectively. Group efficiency order for nematic is derived on the basis of thermal stability as ?OC12H25(n) (linear) > ?OC12H25(n) (nonlinear) > ?OC16H33 (nonlinear).
Identification of highly potent N-acylethanolamine acid amidase (NAAA) inhibitors: Optimization of the terminal phenyl moiety of oxazolidone derivatives
Li, Yuhang,Chen, Qi,Yang, Longhe,Li, Yanting,Zhang, Yang,Qiu, Yan,Ren, Jie,Lu, Canzhong
supporting information, p. 214 - 221 (2017/08/16)
N-acylethanolamine acid amidase (NAAA) is a cysteine hydrolase that participates in the deactivation of fatty acid ethanolamides, such as palmitoylethanolamide (PEA). NAAA inhibition may provide a potential therapeutic strategy for the treatment of diseases in which higher PEA level is desired. In the present study, we reported the structure-activity relationship (SAR) studies for oxazolidone derivatives as NAAA inhibitors. A series of substituents or alkyl replacements for the terminal phenyl ring of oxazolidone derivatives were examined. The results showed that the inhibition potency of these oxazolidone derivatives towards NAAA depends on the sizes, flexibility, and lipophilicity of the terminal groups. SAR results suggested that small lipophilic 3-phenyl substituents or hydroxy-containing 4-phenyl substituents were preferable for optimal potency. Furthermore, the distal aliphatic replacement is also preferred for high inhibitory potency. Rapid dilution and kinetic analysis suggested that oxazolidone derivatives with different terminal phenyl moieties inhibited NAAA via different mechanisms. This study identified several highly potent NAAA inhibitors, including 1a (F215, IC50 = 0.009 μM), 1o (IC50 = 0.061 μM) and 2e (IC50 = 0.092 μM), and also determined structural requirements of oxazolidone derivatives for potent inhibition against NAAA.
Mesomorphism dependence on central bridge (-COO-CH2-) and terminal end group (-Br)
Marathe, Rajesh B.,Doshi
, p. 122 - 131 (2016/02/19)
A novel series of liquid crystalline (LC) ester materials has been synthesized and studied with a view to understanding the effects of molecular structure on LC behavior. The homologous series of eleven members is entirely enantiotropically smectogenic without exhibition of a nematic phase. Transition temperatures and the texture of smectic phase was determined by an optical polarizing microscope equipped with a heating stage (POM). Transition curves (Cr-Sm and Sm-I) showing phase behavior in a phase diagram behave in a normal manner. Textures of smectic phase are focal conic fan shaped of the type Smectic-A or Smectic-C. An odd-even effect is exhibited by the Sm-I transition curve. The average thermal stability for smectic is 91.2°C and the mesogenic phase length ranges between 3.6°C and 39.3°C. Thus, the novel smectogenic homologous series is a middle-ordered melting type whose LC phase is relatively middle ordered. The LC properties of the present series are compared with a structurally similar homologous series. Analytical and spectral data support the molecular structures.
