62435-37-4Relevant 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.
“Synthesis, Mesomorphic and DFT Studies of Chalcone Derived Room Temperature Liquid Crystal with Presence of Lateral Nitro and N, N-Dimethyl Amino Terminal Group”
Shukla, Devendra K.,Sharma, Vinay S.,Prajapat, Varsha,Patel
, p. 8 - 26 (2019/10/14)
In this present article, we wish to report on the liquid-crystalline properties of chalcone-ester based homologous series of compounds having aliphatic chain length in n-alkoxy group (n = 1 to 10, 12, 14, 16, 18). The present series consisted thirteen compounds, in which comp.C1 and C2 shows nonliquid crystalline properties, while comp.C3 to C7 display SmC phase and comp.C8 to C18 exhibits only nematic phase. Textural pattern of presently synthesized compounds are schlieren and threaded type. All this compounds were well characterized by elemental analysis, FT-IR and 1H NMR. Phase transition temperatures of present synthesised compounds were determined by optical polarising microscopy (POM), differential scanning calorimetric (DSC). Detailed XRD investigation endorses the presence of the nematic phase in higher homologues and SmC phase in lower homologues. It is shown that chalcone with ester as linking unit favors a calamitic liquid crystalline behaviour in molecules. To get more insights, the DFT based HOMO, LUMO studies are carried out which supports intramolecular charge transfer interactions in this class of mesogens. Chalconyl ester based compounds C3 to C12 shows antibacterial as well as antifungal activity compared with corresponding standard drugs.
Synthesis, characterization, crystal structure and liquid crystal studies of some symmetric naphthalene derivative molecules
Srinivasa,Palakshamurthy,Devarajegowda,Hariprasad
, p. 620 - 626 (2018/09/18)
The synthesis of a series of symmetrical liquid crystals having naphthalene as the central rigid core and attached to long chain flexible 4′-alkoxybenzoate moiety at positions 2,6 - of the aromatic ring are reported. The mesophase behavior of the molecules was investigated using differential scanning calorimetry (DSC), polarizing optical microscopy (POM) and X-ray diffraction studies. The studies reveal that the synthesized compounds exhibit stable enantiotropic mesophase of Smectic A (SmA) and Nematic (N) phase. The mesophase appearance is independent of the length of the alkyl chain. The molecular structure was determined by single crystal X-ray diffraction technique. The derivative with n-heptyloxy- flexible chain crystallizes under triclinic, P1ˉspace group with unit cell dimension a = 5.569(3) ? b = 10.540(5) ? c = 15.254(9) ? α = 73.434(18)o, β = 80.807(19)o and γ = 82.02(2)o, V = 843.1(8) ?3. The dihedral angle between the naphthalene ring system and the benzoate moiety is 63.63(2)o.
New chalcone based liquid crystals with allylidene amino linking unit: Synthesis and characterization
Sharma, Vinay S.,Sharma, Anuj S.,Jadeja, Upendra H.,Suthar, Deepak
, p. 64 - 81 (2019/02/24)
In this study, the synthesis, structural characterization and mesomorphic properties of newly thirteen calamitic shaped compounds derived from allylidene amino chalcone and 4-n-alkoxy benzoyloxy benzoic acid. Comp.H1 to H3 exhibited nonliquid crystalline nature, while comp.H4 to comp.H18 displayed enantiotropical smectic C phase. Phase transition temperatures of present synthesised compounds were determined by optical polarising microscopy (POM), differential scanning calorimetric (DSC) and powder X-ray diffraction (PXRD) techniques. Thermal stabilities of smectic to isotropic phase are 150.0 °C and temperature range of mesophase is in decreasing order from comp.H3 to comp.H18 respectively. The presences of SmC phase are the type of broken fan and needle type in present synthesized series. It is also shown that presence of chalcone amino allylidene central linking group favors a calamitic liquid crystalline behaviour in molecules with lower member to higher member aliphatic side chain in alkoxy group (-OR).
λ-Shaped mesogens based on chalconyl ester core having variable side chain: Synthesis and characterisation
Sharma, Vinay S.,Suthar, Deepak,Sharma, Anuj S.
, p. 100 - 118 (2019/02/24)
In present study, we have synthesized two newly chalconyl-ester core LCs having variable side chain and fixed disubstituted butoxy group at another terminal end. All this compounds were well characterized by elemental analysis, FT-IR, 1H NMR. The mesomorphic properties of these compounds were observed by optical polarized light microscopy (POM) and also confirmed by using differential scanning calorimetry (DSC) and X-ray diffraction pattern (XRD). Detailed XRD investigation endorses the presence of the nematic phase in higher angle region and SmC phase in lower angle region. In addition, it is found that all the prepared materials display enantiotropic LCs phases except first four members in series-1 and first member in series-2. Thermal stability of SmC and nematic phase of series-1 is higher as compare to series-2. To get more insights, the DFT based HOMO, LUMO studies are carried out which supports intramolecular charge transfer interactions and stability in this class of mesogens.
Benzimidazole based mesogenic Schiff-bases: Synthesis and characterization
Dubey, Ragini,Yerrasani, Rajasekhar,Karunakar,Singh, Angad Kumar,Gupta, Rupali,Ganesan, Vellaichamy,Rao
, p. 106 - 114 (2017/05/25)
Two homologous series of mesogenic Schiff-bases, N-4-((alkoxy)-(phenyl-3-hydroxy-4-(4-(5-methylbenzimidazol))-2-alkoxysalicylaldimine)benzoate (7a–d) and N-4′-(5-methyl-benzimidazole)-phenyl-4-alkoxysalicylaldimine (8a–d) incorporating benzimidazole moiety have been prepared and the molecular structures studied by FT-IR, NMR and ESI-MS spectrometry. Mesogenic behaviour was investigated by polarizing optical microscopy (POM), differential scanning calorimetry (DSC) and variable temperature powder X-ray diffraction (PXRD) techniques. Changing the spacer (ester-linked to non-ester linked) of the Schiff-base results in enhancement of thermal stability and phase transition temperature. The members of series-I show monotropic SmA while those of series-II reflect enantiotropic SmA mesomorphism. An electrochemical study of a representative Schiff base in each series (7d and 8c) showed an electrical band gap 1.26?eV and 1.22?eV respectively.
Calamitic-rod-shaped mesogens based on chalcone esters comprising varying alkoxy and lauryl ester chains: Synthesis, mesomorphism and computational study
Sharma, Vinay S.,Patel, Sunil B.,Sharma, Anuj S.,Patel
, p. 32 - 47 (2017/12/26)
In this studywe have synthesized a new class of compounds incorporating of chalconyl-ester and terminally substituted lauryl group. A series of new chalcones with three aromatic rings is synthesized and characterised 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 optical polarized light microscopy (POM) and confirmed by differential scanning calorimetry (DSC). It is found that all the prepared materials display enantiotropic LCs phases except first two homologue in present series. The lowermember comp. (C3 to C6) display only SmC phase while comp. (C7 to C12) shows smectic C as well as nematic phase. The higher member comp. (C14 to C18) display only nematic phase in heating and cooling condition. To get more insights, the HOMO, LUMO studies are carried out which supports intramolecular charge transfer interactions in this class of mesogens. (Figure presented.).
Lanthanide complexes of a mesogenic Schiff's base having 1,3,4-oxadiazole moiety: Synthesis and characterization
Karunakar,Yerrasani, Rajasekhar,Dubey, Ragini,Singh, Angad Kumar,Rao
, p. 377 - 382 (2016/07/26)
A liquid-crystalline Schiff's base (HL) having 1,3,4-oxadiazole moiety with an octyloxy substituent and a series of lanthanide(III) complexes [Ln(LH)3(NO3)3] (LnIII?=?La, Pr, Nd, Sm, Eu, Tb and Dy; HL?=?N-(4′-(5
Monolayer to Interdigitated Partial Bilayer Smectic C Transition in Thiophene-Based Spacer Mesogens: X-ray Diffraction and 13C Nuclear Magnetic Resonance Studies
Kesava Reddy,Varathan,Lobo, Nitin P.,Roy, Arun,Narasimhaswamy,Ramanathan
, p. 10831 - 10842 (2015/10/12)
Mesophase organization of molecules built with thiophene at the center and linked via flexible spacers to rigid side arm core units and terminal alkoxy chains has been investigated. Thirty homologues realized by varying the span of the spacers as well as the length of the terminal chains have been studied. In addition to the enantiotropic nematic phase observed for all the mesogens, the increase of the spacer as well as the terminal chain lengths resulted in the smectic C phase. The molecular organization in the smectic phase as investigated by temperature dependent X-ray diffraction measurements revealed an interesting behavior that depended on the length of the spacer vis-a-vis the length of the terminal chain. Thus, a tilted interdigitated partial bilayer organization was observed for molecules with a shorter spacer length, while a tilted monolayer arrangement was observed for those with a longer spacer length. High-resolution solid state 13C NMR studies carried out for representative mesogens indicated a U-shape for all the molecules, indicating that intermolecular interactions and molecular dynamics rather than molecular shape are responsible for the observed behavior. Models for the mesophase organization have been considered and the results understood in terms of segregation of incompatible parts of the mesogens combined with steric frustration leading to the observed lamellar order.
Side-on main-chain liquid crystalline polymers prepared by acyclic diene metathesis polymerization and thiol-ene click step-growth polymerization
Yang, Hong,Lv, You-Jing,Lin, Bao-Ping,Zhang, Xue-Qin,Sun, Ying,Guo, Ling-Xiang
, p. 1086 - 1098 (2014/03/21)
In this manuscript, we design and synthesize a series of X-shaped mesogenic monomers, bearing two terminal-alkene tails. Starting from these X-shaped monomers, acyclic diene metathesis polymerization and thiol-ene polyaddition are applied for the first time to prepare two series of side-on main-chain liquid crystalline polymers (LCPs), respectively. The mesomorphic behaviors and structure-property relationships of these new polymers are studied in detail by a combination of 1H NMR, GPC, TGA, DSC, POM, and XRD experiments. It turns out that the length of alkoxy terminal chains of the embedded mesogens and the length of the spacer connecting two adjacent mesogens on the polymer backbones markedly influence the mesomorphic properties. Furthermore, a side-on main-chain liquid crystalline elastomer fiber is prepared by crosslinking the LCP using a UV-sensitive bifunctional benzophenone crosslinker. In comparison with the pure polymer fiber's monodomain alignment, the crosslinked elastomer fiber however shows nonaligned polydomain structure, probably due to the order competitions between the mixed crosslinkers, mesogens, and polymer backbones. 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 1086-1098 A series of X-shaped mesogenic monomers bearing two polymerizable terminal-alkene tails are designed and synthesized. Starting from these X-shaped monomers, acyclic diene metathesis polymerization (ADMET) and thiol-ene click step-growth polymerization are applied to prepare two series of side-on main-chain liquid crystalline polymers, respectively. Copyright
