50909-50-7Relevant articles and documents
Synthesis, characterization of azobenzene and cinnamate ester based calamitic liquid crystalline compounds and their photoresponsive properties
Selvarasu, Chinnaiyan,Kannan, Palaninathan
, p. 176 - 186 (2015)
A series of azobenzene-containing mesogens end-capped with cinnamoyl esters were synthesized and investigated its mesogenic and photochemical properties. Terminal substituents of the molecules were changed with various substituents like CN, Cl, H, CH
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.
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
, (2020/06/20)
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 of novel liquid crystalline and fire retardant molecules based on six-armed cyclotriphosphazene core containing Schiff base and amide linking units
Guan-Seng, Tay,Jamain, Zuhair,Khairuddean, Melati
, p. 28918 - 28934 (2020/08/25)
Nucleophilic substitution reaction between 4-hydroxybenzaldehyde and hexachlorocyclotriphosphazene, HCCP formed hexakis(4-formlyphenoxy)cyclotriphosphazene, 1. Intermediates 2a-e was formed from the alkylation reaction of methyl 4-hydroxybenzoate with alkyl bromide which further reduced to form benzoic acid intermediates. Further reaction of 2a-e and other substituted benzoic acid formed 3a-h, which then reduced to give subsequent amines, 4a-h. Other similar reaction was used to synthesis 4i. Condensation reaction between 1 and 4a-i yielded hexasubstituted cyclotriphosphazene compounds, 5a-i having Schiff base and amide linking units, and these compounds consist of different terminal substituents such as heptyl, nonyl, decyl, dodecyl, tetradecyl, hydroxy, carboxy, chloro, and nitro groups, respectively. Compound 5j with amino substituent at terminal end was formed from the reduction of 5i. All the intermediates and compounds were characterized using Fourier Transform Infrared (FT-IR), Nuclear Magnetic Resonance (NMR) and CHN elemental analysis. Mesophase texture of these compounds were determined using Polarized Optical Microscope (POM) and their mesophase transition were further confirmed using Differential Scanning Calorimetry (DSC). Only compounds 5a-e with alkoxy chains exhibited smectic A phase while other intermediates (1, 2a-e, 3a-h, and 4a-i) and final compounds (5f-j) are found to be non-mesogenic with no liquid crystal behaviour. The confirmation of the identity of the SmA phase was determined using XRD analysis. The study on the structure-properties relationship was conducted in order to determine the effect of the terminal group, length of the chains and linking units to the mesophase behaviour of the compounds. Moreover, the fire retardant properties of these compounds were determined using Limiting Oxygen Index (LOI) testing. Polyester resin with LOI value of 22.53% was used as matrix for moulding in the study. The LOI value increased to 24.71% when this polyester resin incorporated with 1 wt% of HCCP. Generally, all the final compounds showed a positive results with LOI value above 27% and the highest LOI value was belonged to compound 5i with 28.53%. The high thermal stability of the Schiff base molecules and the electron withdrawing group of the amide bonds and nitro group enhanced the fire retardant properties of this compound.
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.
Chiral ionic liquid crystals based on thiourea
Kirchhecker, Sarah,Bruce, Duncan W.
supporting information, p. 2053 - 2056 (2019/02/05)
Chiral ionic liquid crystals based on the S-methyl-N,N′-α-methylarylthiouronium cation have been prepared and studied. Most salts, interestingly including an example with the bistriflimide anion, display a SmA? phase with anion-dependent transition temper
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.
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).
Cluster phases of 4-cyanoresorcinol derived hockey-stick liquid crystals
Alaasar, Mohamed,Poppe, Silvio,Kerzig, Christoph,Klopp, Christoph,Eremin, Alexey,Tschierske, Carsten
supporting information, p. 8454 - 8468 (2017/09/02)
Here, we report the synthesis and investigations of hockey-stick liquid crystalline materials derived from 4-cyanoresorcinol as the central core unit. The effect of distinct linking groups (NN, COO, OOC) and the effect of inverting the direction of the cyano group on the resorcinol core with respect to the different side arms on the liquid crystalline properties were investigated. The self-assembly was characterized by polarising optical microscopy (POM), differential scanning calorimetry (DSC), X-ray diffraction (XRD), electro-optical and second harmonic generation (SHG) experiments and dielectric spectroscopy. It is found that depending on the alkyl chain length, nematic and smectic liquid crystalline phases were observed. All nematic phases exhibited by the compounds with the CN group adjacent to the shorter rod-like arm of the mesogen are NCybA phases composed of large non-tilted (SmA-type) cybotactic clusters, while inverting the direction of the cyano group leads to nematic phases composed of smaller cybotactic clusters (NCybC) with tilted-smectic correlations. The former compounds form additional non-tilted (SmA) and tilted smectic (SmC) composed of polar domains with a strong polar response. There is a transition from synclinic to anticlinic molecular arrangement (SmCs and SmCa phases) with decreasing temperature and mirror symmetry breaking in the SmCs phases. The synclinic-anticlinic transition is associated with a reduction of the polar domain size, being opposite to observations made for related bent-core compounds and is attributed to the combined effects of nano-segregation and entropy.
