62718-63-2Relevant academic research and scientific papers
“Effect of the linking unit on the calamitic-shaped liquid crystal: a comparative study of two homologous series of benzoate and cinnamate linked compounds”
Kashyap, Dinesh,Patel, Sunil,Prajapat, Varsha,Sharma, Vinay,Vasava, Dilip
, p. 58 - 70 (2019/08/28)
Two homologous series based on three linking groups have been synthesized and well characterized 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 using optical polarized microscopy (POM) and confirmed by differential scanning calorimetry (DSC) analysis. In this present investigation, we have synthesized two homologous series viz. (E)-4-(3-(4-(tetra decanoyloxy) phenyl) acryloyl) phenyl-4-n-alkoxy benzoate (Series-1) and 4-((E)-3-(4-(((E)-3-(4-n-alkoxy phenyl) acryloyl) oxy) phenyl)-3-oxo prop-1-en-1-yl) phenyl tetradecanoate (Series-2). Both of the series are differing with respect to the first linking group. All the homologous in following series displays LC properties on heating as well as cooling condition except first four homologous (C1 to C4) in series-1 and six homologous (C1 to C6) in series-2. To get more insights, the HOMO, LUMO studies are carried out which supports intramolecular charge transfer interactions in this class of mesogens.
Bowl-shaped fluorescent liquid crystals derived from 4-: Tert butyl calix[4]arene and trans cinnamic acid derivatives
Sharma, Vinay S.,Singh, Hemant Kumar,Sharma, Anuj S.,Shah, Akshara P.,Shah, Priyanka A.
, p. 15575 - 15584 (2019/10/19)
A new family of bowl-shaped molecules with a calix[4]arene rigid core appended by four-side and two-side substitution with trans 4-n-alkoxy cinnamic acid has been synthesized and well characterized. The LC behaviours of the novel materials were studied by using optical polarising microscopy, differential scanning calorimetry and high-temperature powder X-ray diffraction methods to confirm the smectic organization. It is found that all of the prepared materials display enantiotropic LC phases in the present series-1 (1d4-1, 1d5-l, 1d8-1, 1d10-l, 1d12-l, 1d14-l) and series-2 (1d4-1l, 1d5-ll, 1d8-1l, 1d10-ll, 1d12-ll, 1d14-ll). The electrochemical behaviour shows the higher reactivity of the proposed derivatives, which is in good agreement with the DFT values. The relationship between the structure and the mesomorphic behaviour of the compounds in both series is discussed. These synthesized supramolecular compounds show blue luminescence in solution as well as in solid thin films under long wavelength UV light. To get more insights, HOMO and LUMO studies were carried out, which support intramolecular charge transfer interactions in this class of mesogens.
Mesomorphism dependence on central bridge and tail ended polar group
Ranchchh, Avani R.,Chavda, Kavita,Bhanderi, Roshani,Patel, Suman,Bhoya
, p. 33 - 42 (2019/02/24)
A novel azoester homologous series of laterally and terminally substituted viz, RO–C6H4–CH=CH–COO–C6H3–(CH3) –N=N–C6H4–Cl is synthesized, characterized and studied with a view to understand and establish the relation between molecular structure and thermotropic liquid crystalline property of its homologs. Series consists of twelve homologs. LC properties commence from very first member of a series and continue up to last homolog as enantiotropic nematic with absence of smectic property even in the monotropic condition. Transition temperatures of homologs were determined by polarizing optical microscopy equipped with a heating stage. The transition curves Cr?N and N?I behaved in normal manner. Thermal stability for nematic is 196.7?C whose mesophaselength ranges from 35°C to 131°C.
Mesomorphism dependence on molecular rigidity and flexibility
Ranchchh, Avani R.,Bhoya
, p. 43 - 51 (2019/02/24)
A novel homologous series of liquid crystalline properties is synthesized and studied with a view to understand the effect of molecular structure on its thermotropic properties. Novel homologous series consisted of thirteen homologs. All the homologs are enantiotropically smectogenic with absence of nematic property even in the monotropic condition. Textures of the homologs as observed through an optical hot stage polarizing microscopy. The mesophase temperature range vary minimum from 6.0°C to a maximum 37.0°C at the methyloxy and propyloxy derivatives of a series respectively with its thermal stability (Sm–I) 127.0°C. Transition curves of a phase diagram behaved in normal manner. Odd–even effect is observed for Sm–I transition curve.
“Dependence of Mesomorphism in Combination with Fluoro and Chloro Groups”
Ranchchh, Avani R.,Tharesha, Bhavna R.,Bhoya
, p. 49 - 58 (2019/07/03)
A novel azoester homologous series with chloro lateral group and a fluoro terminal end group was synthesized and characterized for mesomorphic properties. It consists of thirteen azo ester derivatives from trans-4-n-alkoxy cinnamic acid with 4-hydroxy-3-chloro phenyl azo-3-chloro-4-fluoro benzene. Mesomorphic property commences from C4homologue as smectic.C1 to C3 member of the series are non-mesomorphic. C4 to C18 homologous are enantiotropic smectic A phase. The nematic mesophase is totally absent. Texture and transition temperatures of the homologues are determined by an optical polarizing microscopy equipped with heating stage. 1H NMR, IR spectra, mass spectra, of some member is included. The spectroscopic analysis supports the molecular structure. A phase diagram is used to illustrate the mesomorphic behaviour across the series. Mesophaselength for smectic is varying from18.0°C to 69.00C. Mesomorphic properties of the novel azoester series are compared with structurally similar series.
Molecular flexibility dependence on mesogenic behaviors of isomeric and nonisomeric series
Rakhasia,Ranchchh, Avani R.,Bhoya
, p. 159 - 167 (2017/03/08)
A novel homologous series containing vinyl ester and azomethane central bridges and n-alkoxy as well as 3″,4″-dimethyl groups as flexible terminal/lateral groups viz. RO?C6H4?CH = CH?COO?C6H4?N?CH?C6H3-(CH3)2 have been synthesized and studied with a view to establishing the relation between molecular structure and thermotropic liquid crystal (LC) properties with reference to molecular flexibility within the series. The series consists of twelve homologues (C1 to C16). C6 and C7 homologues are smectogenic plus nematogenic and C8 to C16 homologues are only smectogenic, and the rest of the homologues (C1 to C5) are nonmesomorphic. Transition temperatures and the textures of the homologues were determined using an optical polarizing microscope equipped with a heating stage (POM). The textures of a nematic phase are threaded or Schlieren and that of a smectic phase are of the A or C type. Analytical, thermal and spectral data support the molecular structures. Smectic and nematic thermal stabilities are 116.85°C and 147.5°C, respectively. Whose Sm?N/I and N-I mesophase lengths are varied between 15°C to 21°C and 25°C to 62°C, respectively. The novel compounds are compared with structurally-similar series.
Synthesis, characterization, and mesomorphic investigation of vinyl ester-substituted chalcones and effect of lateral ?NO2 and ?OCH3 group
Sharma, Vinay S.,Patel
, p. 241 - 251 (2017/03/08)
A novel homologous series of α-4-(4′-n-alkoxy cinnamoyloxy) phenyl β-2″-nitro, 3″–4″ di methoxy benzoyl ethylenes, H2n + 1CnO?C6H4?CH?CH?COO?C6H4?CO?CH?CH?C6H2(NO2) (OCH3)2 (n = 1–8, 10, 12, 14, 16, 18) has been synthesized. All these compounds have been characterized by suitable spectroscopic techniques. C1 homologue is nonmesogenic, while C2 homologue shows enantiotropic nematogenic property and the rest of the homologous (C3?C18) displayed enantiotropically smectogenic plus nematogenic phase. Phase transition temperatures and textures of the LC phase were determined by an optical polarizing microscopy (POM) equipped with a heating stage. The mesomorphic properties of these compounds were confirmed by differential scanning calorimetry (DSC) analysis.
Mesomorphic study of novel chalconyl-ester-based nonisomeric series: Synthesis and characterization
Sharma, Vinay S.,Patel
, p. 13 - 27 (2017/03/08)
A newly designed homologues series: 3-(3-(4-(Dimethylamino) phenyl) acrylonyl) phenyl 3-(4-n-alkoxyphenyl) acrylate has been synthesized and studied through chalconyl ester linking group at (meta) position. The series consists of 13 compounds, in which C1 to C4 homologue are nonliquid crystal, while C5 to C18 exhibit nematic phase, and C12 to C18 shows smectic and nematic phase with enantiotropically manner. Mesophase image of present compounds are rod like, needle and threaded type textures investigated by POM. All this compounds were characterized by elemental analysis, FT-IR and 1H NMR. The mesomorphism is measured by POM, DSC, and molecular packing is determined by XRD technique. The following synthesized chalconyl ester-based compounds C5 to C12 shows antibacterial as well as antifungal activity compared with corresponding standard drugs. Analytical and spectral data confirmed the molecular structures of homologous series.
Study the effects of terminal side chain and –nitro group on mesomorphic behaviour of cinnamate-chalconyl based liquid crystal
Sharma, Vinay S.,Patel
, p. 1 - 12 (2017/03/08)
The influence of the terminal side chain and lateral nitro on mesomorphism due to the flexibility and polarity of lateral group is investigated. A new homologues series is synthesized to accomplish this aim. The C1 to C3 homologue are nonmesomorphic, while the rest of the homologues exhibit enantiotropic nematic and smectic properties. The texture of the nematic mesophase is of threaded, Schlieren and droplets type. All these compounds were characterized by elemental analyses and spectroscopic techniques of FTIR and 1H Nuclear magnetic resonance (NMR). The phase behaviour was studied by polarizing optical microscopy (POM), differential scanning calorimetry (DSC), and X-ray diffraction techniques.
Tuning the mesomorphic properties of nonisomeric chalconyl-ester bases homologous series: The effect of tail group
Sharma, Vinay S.,Patel
, p. 40 - 51 (2017/03/08)
The mesomorphic properties of nonlinear chalconyl ester homologous series can be tuned in a predictable fashion with tail groups (-OC16H33) substituents on the terminal side. Novel series consisted thirteen members (C1–C8, C10, C12, C14, C16, C18). C1 to C5 homologues are nonliquid crystal, C6 to C14 homologues shows nematic mesophase enantiotropically, while C16, C18 exhibits smectic as well nematic properties. The texture of the nematic mesophase is of fan shaped, schlieren and nematic droplets type. All these compounds were characterized by elemental analyses and spectroscopic techniques such as [FTIR] and 1H Nuclear magnetic resonance [NMR] spectroscopy. The mesomorphic properties of these compoundswere observed by optical polarized light microscopy (POM) and differential scanning calorimetry (DSC).
