89027-81-6Relevant articles and documents
Rare-earth-containing magnetic liquid crystals
Binnemans, Koen,Galyametdinov, Yury G.,Van Deun, Rik,Bruce, Duncan W.,Collinson, Simon R.,Polishchuk, Arkadiy P.,Bikchantaev, Ildar,Haase, Wolfgang,Prosvirin, Andrey V.,Tinchurina, Larisa,Litvinov, Igor,Gubajdullin, Ajdar,Rakhmatullin, Ajdar,Uytterhoeven, Koen,Van Meervelt, Luc
, p. 4335 - 4344 (2000)
Rare-earth-containing metallomesogens with 4-alkoxy-N-alkyl-2- hydroxybenzaldimine ligands are reported. The stoichiometry of the complexes is [Ln(LH)3(NO3)3], where Ln is the trivalent rare-earth ion (Y, La, and Pr to Lu, except Pm) and LH is the Schiff base. The Schiff base ligands are in the zwitterionic form and coordinate through the phenolic oxygen only. The three nitrate groups coordinate in a bidentate fashion. The X-ray single- crystal structures of the nonmesogenic homologous complexes [Ln(LH)3(NO3)3], where Ln = Nd(III), Tb(III), and Dy(III) and LH = CH3OC6H3(2-OH)CH=NC4H9, are described. Although the Schiff base ligands do not exhibit a mesophase, the metal complexes do (SmA phase). The mesogenic rare-earth complexes were studied by NMR, IR, EPR, magnetic susceptibility measurements, X-ray diffraction, and molecular modeling. The metal complexes in the mesophase have a very large magnetic anisotropy, so that these magnetic liquid crystals can easily be aligned by an external magnetic field.
The influence of molecular flexibility on the mesogenic behavior of a new homologous series based on azo-azomethine: Synthesis, characterization, photoisomerization and DFT study
Jadeja, Rajendrasinh N.,Katariya, Kanubhai D.,Nakum, Kiran J.,Savani, Chirag J.
, (2021/10/05)
Through condensation of 2-hydroxy-4-n-alkoxybenzaldehyde (n = 2 to 8, 10, 12, 14, 16, 18) with (E)-4-((2,4-dimethylphenyl)diazenyl) benzene-1,3-diamine, new homologous series of rod shaped calamite liquid crystals based on azo-azomethine have been prepared. All synthesized compounds were characterized by FT-IR, 1H NMR, and 13C NMR spectroscopy. Use Differential Scanning Calorimeter (DSC) and Polarizing Optical Microscope (POM) to check the liquid crystal properties of all synthetic compounds. In the homologous series, all the compounds are mesogenic; some of them are in the nematic phase; some of them appear in the smectic A phase, and some appear in the nematic and smectic A phases. UV–vis pectroscopy was used to study the photoisomerization in chloroform. DFT (Density functional theory) level calculations and complete geometric optimization of all synthetic compounds are performed using B3LYP/6-31+G (d, p) basis sets.
Development of nematic and orthogonal smectic phases in short-core fluorinated hockey-stick shaped liquid crystal compounds
Upadhyaya, Kalpana,Ghosh, Sharmistha,Khan, Raj Kumar,Pratibha,Rao, Nandiraju V.S.
, (2019/11/26)
Here we report synthesis and investigations on novel short-core hockey-stick shaped molecules bearing a 4-n-alkyloxy-2-hydroxybenzylidene moiety at one end and polar fluoro-biphenyl moiety at the other end. The polar chloro and fluoro substituent at the lateral position of the core confers nematic and orthogonal smectic mesomorphism. The mesophase morphology is characterized by polarizing optical microscopy (POM), differential scanning calorimetry (DSC), X-ray diffraction (XRD), electro-optical study and dielectric spectroscopy. The fluorinated compounds 1b (n = 16) and 1c (n = 18) have long terminal hydrocarbon tail and show orthogonal smectic phases with antiferroelectric switching behaviour. The chlorinated compound 2e (n = 8) with relatively short terminal chain length exhibits only a monotropic nematic phase on cooling. The nematic phase is comprised of cybotactic clusters as confirmed by XRD and exhibits electro-optic switching. The compound 2i (n = 12) manifests a short range enantiotropic nematic and additional orthogonal smectic phase. Dielectric spectroscopy reveals polar correlations in the nematic and smectic phases.
Synthesis, characterization, and mesomorphic properties of some new Schiff base homologues series and their Cu(II) complexes
Nakum, Kiran J.,Katariya, Kanubhai D.,Jadeja, Rajendrasinh N.
, p. 1 - 13 (2021/02/02)
In present study, we have synthesized two homologous series of some new Schiff base of 4-n-alkoxy-2-hydroxy benzaldehyde (n = 2–8, 10, 12, 14, 16, 18) with 4-amino acetanilide and their corresponding Cu(II) complexes. A series of new Schiff base containing two aromatic rings have been synthesized and characterized by various spectroanalytical techniques including FT-IR and 1H NMR. The mesomorphic properties of these compounds were observed by optical polarized light microscopy (POM) and confirmed by differential scanning calorimetry (DSC) study. It has been observed that all the newly synthesized compounds exhibit wide range SmA phase.
Schiff base of 4-n-alkoxy-2-hydroxy benzaldehyde with 4-amino acetophenone and their Cu(II) complexes: synthesis, characterization and mesomorphic behavior
Nakum, Kiran J.,Katariya, Kanubhai D.,Jadeja,Prajapati
, p. 1 - 13 (2019/12/12)
New homologous series of Schiff’s base of 4-n-Alkoxy-2-hydroxy benzaldehyde (n = 2 to 8, 10, 12, 14, 16, 18) with 4-amino acetophenone and their Cu(II) metal complexes have been synthesized. The compounds were characterized using various spectroscopic techniques including FT-IR, 1H-NMR, 13C-NMR. Mesomorphic properties of these compounds have been investigated with polarizing optical microscope and differential scanning calorimeter. These compounds exhibit wide range SmA phase as confirmed by their typical optical texture under polarizing microscope.
Molecular modeling and snake venom phospholipase A2 inhibition by phenolic compounds: Structure-activity relationship
Alam, Md. Iqbal,Alam, Mohammed A.,Alam, Ozair,Nargotra, Amit,Taneja, Subhash Chandra,Koul, Surrinder
, p. 209 - 219 (2016/03/22)
In our earlier study, we have reported that a phenolic compound 2-hydroxy-4-methoxybenzaldehyde from Janakia arayalpatra root extract was active against Viper and Cobra envenomations. Based on the structure of this natural product, libraries of synthetic structurally variant phenolic compounds were studied through molecular docking on the venom protein. To validate the activity of eight selected compounds, we have tested them in in vivo and in vitro models. The compound 21 (2-hydroxy-3-methoxy benzaldehyde), 22 (2-hydroxy-4-methoxybenzaldehyde) and 35 (2-hydroxy-3-methoxybenzylalcohol) were found to be active against venom-induced pathophysiological changes. The compounds 20, 15 and 35 displayed maximum anti-hemorrhagic, anti-lethal and PLA2 inhibitory activity respectively. In terms of SAR, the presence of a formyl group in conjunction with a phenolic group was seen as a significant contributor towards increasing the antivenom activity. The above observations confirmed the anti-venom activity of the phenolic compounds which needs to be further investigated for the development of new anti-snake venom leads.
Design, synthesis and mesomorphic behaviour of a four-ring achiral bent-core liquid crystal in the nematic phase
Nafees, Amina,Sinha, Aloka,Rao, Nandiraju V. S.,Kalita, Gayatri,Mohiuddin, Golam,Paul, Manoj Kumar
, p. 43069 - 43079 (2016/05/24)
Bent-core nematics have attracted growing interest because of the unconventional properties and extraordinary effects exhibited by these liquid crystalline phases. In this report we design, synthesize and characterize four different four-ring achiral bent
Synthesis and mesomorphism of new chiral imines and copper(II) complexes
Paul, Manoj K.,Kalita, Gayatri,Laskar, Atiqur Rahman,Choudhury, Trirup D.,Rao, Nandiraju V.S.
, p. 219 - 226 (2013/05/08)
The synthesis, characterization and mesomorphic properties of a series of N-(2-hydroxy-4-n-alkyloxybenzylidene) 4′-amino-2-methylbutylcinnamate and their copper(II) complexes are reported. The imines exhibited smectic A (SmA) and chiral smectic C (SmC·) phases while their copper(II) complexes displayed SmA-SmC phase variant. The compounds have been characterized by elemental analysis and spectroscopic studies. The phase transition temperatures were detected by differential scanning calorimetry (DSC) analysis and the phases are confirmed by polarizing optical microscopy (POM). The chiral phase (SmC·) of the ligand disappeared on complexation. The unwinding of the helical superstructure of SmC· phase under the influence of electric field and the observed optical textures of SmC · phase are also discussed.
Nematic phases in achiral unsymmetrical four-ring bent-core azo compounds possessing strongly polar cyano and nitro moieties as end substituents: Synthesis and characterization
Debnath, Somen,Mohiuddin, Golam,Turlapati, Srikanth,Begum, Nazma,Sarkar, Dipika Debnath,Nandiraju Rao
, p. 447 - 455 (2013/10/08)
Achiral unsymmetrical four-ring bent-core liquid crystals with strongly polar cyano and nitro moieties as substituents at one end and alkyloxy group (butyl to dodecyl) at the other end have been synthesized by a simple and straight forward synthetic method. The four phenyl rings are connected through azo, ester and imine linkages respectively and bent unit is derived from 3-aminobenzoicacid with 2-methyl substituent in the transverse direction of the molecule. The molecular structure characterization is consistent with elemental and spectroscopic analysis data. The materials thermal behaviour and phase characterization have been investigated by differential scanning calorimetry and polarizing optical microscopy. All the compounds exhibit enantiotropic nematic phase over a wide temperature range. The light induced cis-trans isomerization is also discussed.
Synthesis, characterization and mesomorphic properties of unsymmetrical N-[4-(alkoxy)-2-hydroxybenzylidene]-N-(4-alkoxybenzylidene) azines and their copper (II) complexes
Pandey, Ashwini,Singh, Bachcha
experimental part, p. 123 - 133 (2012/05/05)
A new series of mesogenic unsymmetrical azines, N-[4-(alkoxy)-2- hydroxybenzylidene]-N-(4-n-alkoxybenzylidene) azines, ROC6H 4CHNNCHC6H3OHOR, where RCmH2 m+1 (m = 6, 8, 10, 12, and 14), and their copper (II) complexes has been synthesized. They were characterized by elemental analyses, Fourier transform infrared (FT-IR), 1H and 13C nuclear magnetic resonance (NMR) spectra, ultraviolet (UV)-visible, and magnetic susceptibility measurements. The copper (II) complexes are square planar. The mesomorphic properties of these compounds were investigated by differential scanning calorimetry and polarizing microscopy. The unsymmetrical azines with m = 6, 12, and 14 exhibit monotropic nematic, enantiotropic, and monotropic smectic A phases, whereas azines with m = 8 display enantiotropic nematic and m = 10 display both enantiotropic smectic A and nematic mesophases in the heating and cooling cycles. The copper (II) complexes of the azines are nonmesomorphic in nature with high clearing temperatures and displayed polymorphism (crystal-crystal transitions) in both the heating and cooling cycles.
