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We report the synthesis and liquid crystalline properties of two new homologous series of calamitic liquid crystals containing a substituted pyrazole ring within the central core of 4-(4-n-alkoxybenzoyl)-5-methyl-2-phenyl-2,4-dihydro-3H-pyrazole-3-one and 4-(4-n-alkoxybenzoyl)-5-methyl-2-(4-methylphenyl)-2,4-dihydro-3H-pyrazole-3-one and characterization of the compounds done by elemental analysis, FT-IR, 1H-NMR, and mass spectrometry. Phase transition behavior of these compounds was assessed with the help of polarizing optical microscopy (POM) and differential scanning calorimetry (DSC). Both series show liquid crystalline properties from the heptyl homologue. Middle members of Series-A and Series-B exhibit nemetogenic behavior and higher homologues exhibit only smectogenic behavior. [ABSTRACT FROM PUBLISHER]

In order to investigate the influence of the central linkage and terminal substitutions on mesophase behaviour of liquid crystalline compounds we have synthesised six homologues series viz. 4'-(naphthalen-1-yldiazenyl)biphenyl-4-yl-4-alkoxybenzoate (Series-A), 4'-[(4-cyanophenyl)diazenyl]biphenyl-4-yl-4-alkoxybenzoate (Series-B), 4'-[(4-fluorophenyl)diazenyl]biphenyl-4-yl-4-alkoxybenzoate (Series-C), 4'-(naphthalen-1-yldiazenyl)biphenyl-4-yl(2E)-3-[4-alkoxyphenyl]prop-2-enoate (Series-D), 4'-[(4-cyanophenyl)diazenyl]biphenyl-4-yl(2E)-3-[4-alkoxyphenyl]prop-2-enoate (Series-E) and 4'-[(4-fluorophenyl)diazenyl]biphenyl-4-yl(2E)-3-[4-alkoxyphenyl]prop-2-enoate (Series-F). Series-A, -B and -C have azo-ester central linkages whereas Series-D, -E and -F have azo-cinnamate central linkages and naphthalene, 4-cyanophenyl and 4-fluorophenyl as terminal groups, respectively. All these compounds were characterised by elemental analyses and spectroscopic techniques (ultraviolet-visible, Fourier transform infrared, proton and carbon nuclear magnetic resonance and mass spectrometry. Their mesomorphic properties were measured by optical polarised microscopy and differential scanning calorimetry. All the derivatives are showing enantiotropic mesomorphism. [ABSTRACT FROM AUTHOR]

We synthesized and studied the coordinating behaviour of chalcone based ligands derived from DHA and n-alkoxy benzaldehyde and their complexes of VO(IV) and MoO(V). The chalcone ligands are characterized by elemental analyses, UV-visible, IR, (1)H NMR, and mass spectra. The resulting oxocation complexes are also characterized by elemental analyses, IR, (1)H NMR, electronic, electron spin resonance spectra, magnetic susceptibility measurement and molar conductance studies. The IR and (1)H NMR spectral data suggest that the chalcone ligands behave as a monobasic bidentate with O:O donor sequence towards metal ion. The molar conductivity data show them to be non-electrolytes. From the electronic, magnetic and ESR spectral data suggest that all the chalcone ligand complexes of VO(IV) and MoO(V) have distorted octahedral geometry., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Microwave synthesis, is green chemical method, simple, sensitive, reducing solvent amount and reaction time. The attempt was made to synthesize the unsymmetrical tetradentate N(2)O(2) ligands and their VO(IV) and MoO(V) unsymmetrical tetradentate Schiff base complexes by classical and microwave techniques using domestic microwave oven. The resulting unsymmetrical Schiff base ligands L(1)-L(3) characterized by different spectral methods. Their complexes with oxocations of VO(IV) and MoO(V) have been synthesized and characterized by elemental analyses, conductometric measurements, infrared and electronic absorption, (1)H NMR spectra, mass spectrometry, ESR spectra, magnetic susceptibility measurement and thermal study. The study suggests that the oxo metal ion is bonded to the ligand through the oxygen and imino nitrogen and the geometry around metal ion is distorted octahedral., (Copyright © 2011 Elsevier B.V. All rights reserved.)

The Schiff base tetradentate ligands N,N-bis-(3,5-dimethyl-1-p-tolyl-1H-pyrazol-4-ylmethylene)-ethane-1,2-diamine (H(2)L(1)), N,N-bis-(3,5-dimethyl-1-p-sulfonyl-1H-pyrazol-4-ylmethylene)-ethane-1,2-diamine (H(2)L(2)), N,N-bis-(3,5-dimethyl-1-p-tolyl-1H-pyrazol-4-ylmethylene)-benzene-1,2-diamine (H(2)L(3)) and N,N-bis-(3,5-dimethyl-1-p-sulfonyl-1H-pyrazol-4-ylmethylene)-benzene-1,2-diamine (H(2)L(4)) were prepared from the reaction between 5-oxo-3-methyl-1-p-tolyl-1H-pyrazole-4-carbaldehyde or 4-(4-formyl-5-oxo-3-methyl-pyrazol-1-yl)-benzenesulfonic acid and o-phenylenediamine or ethylenediamine. And these are characterized by elemental analysis, FT-IR, (1)H NMR and GC-MS. The corresponding Schiff base complexes of Mn(III) were prepared by condensation of [Mn(3)(mu(3)-O)(OAc)(6)(H(2)O)(3)].3H(2)O with ligands H(2)L(1), H(2)L(2), H(2)L(3) and H(2)L(4). All these complexes have been characterized by elemental analysis, magnetic susceptibility, X-ray crystallography, conductometry measurement, FT-IR, electronic spectra and mass (FAB) spectrometry. Thermal behaviour of the complexes has been studied by TGA, DTA and DSC. Electronic spectra and magnetic susceptibility measurements indicate octahedral stereochemistry of manganese (III) complexes, while non-electrolytic behaviour complexes indicate the absence of counter ion., (Copyright 2009. Published by Elsevier B.V.)

Synthesis and evaluation of six new oxovanadium (IV) complexes, formed by the interaction of vanadyl sulphate pentahydrate and the Schiff base, viz.; (HL(1))-(HL(3)) and (HL(4))-(HL(6)) such as 5-hydroxy-3-methyl-1(2-chloro)phenyl-1H-pyrazolone-4-carbaldehyde (I), 5-hydroxy-3-methyl-1(3-chloro)phenyl-1H-pyrazolone-4-carbaldehyde (II) and 5-hydroxy-3-methyl-1(3-sulphoamido)phenyl-1H-pyrazolone-4-carbaldehyde (III) with ethanol amine and propanol amine, respectively, in aqueous ethanol medium. The ligands and their Schiff base ligands have been characterized by elemental analyses, IR and (1)H NMR. The resulting complexes have been characterized by elemental analyses, IR, (1)H NMR, mass, electronic, electron spin resonance spectra, magnetic susceptibility measurement, molar conductance and thermal studies. The IR spectral data suggest that the ligand behaves as a dibasic bidentate with ON donor sequence towards metal ion. The molar conductivity data show them to be non-electrolytes. From the electronic, magnetic and ESR spectral data suggest that all the oxovanadium (IV) complexes have distorted octahedral geometry.