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Showing papers by "Bachcha Singh published in 2011"


Journal ArticleDOI
TL;DR: In this article, a series of mesogenic aroylhydrazone-based ligands, N-[4-(4′)-alkoxy)benzoyloxybenzylidene]-N′-[4″-alkoxybenzinoyl]hydrazine with either the same or different peripheral alkyl chains, and nickel(II) complexes of some of them have been synthesised.
Abstract: A new series of mesogenic aroylhydrazone-based ligands, N-[4-(4′-alkoxy)benzoyloxybenzylidene]-N′-[4″-alkoxybenzoyl]hydrazine with either the same or different peripheral alkyl chains, and nickel(II) complexes of some of them have been synthesised They were characterised by elemental analyses, Fourier transform infrared, proton and carbon nuclear magnetic resonance and ultraviolet-visible spectroscopy The mesomorphic properties of these compounds were investigated by differential scanning calorimetry and polarising optical microscopy All the aroylhydrazones, except those with no lateral chains on either end of the molecule and where m = n = 14, 16, exhibit a monotropic or enantiotropic smectic C mesophase, which are almost insensitive to the peripheral alkoxy chain length The square planar nickel(II) complexes of the ligands show only an isotropic phase at higher temperature (>175°C) and no mesogenic nature is observed Density functional theory calculations have been performed using the GAUSSIAN-03 p

11 citations


Journal ArticleDOI
TL;DR: A series of transition metal complexes K[MII(s-bqdi)2][FeIII(s -bqDI)2(CN)2]· 10H2O (s- bqdi,= semibenzoquinonediiminate, MII(2), Ni (3), and Cu (4)) have been synthesized.
Abstract: A new series of transition metal complexes K[MII(s-bqdi)2][FeIII(s-bqdi)2(CN)2] · 10H2O (s-bqdi = semibenzoquinonediiminate, MII = Co (2), Ni (3), and Cu (4)) have been synthesized. These complexes have been characterized by elemental analyses, FT IR, Far IR, FAB mass, UV-Vis, TGA, CV measurements, and powder XRD. The powder XRD patterns of 2, 3, and 4 show that they are isostructural with hexagonal primitive lattice structures. The coordination polymers display 1-D chain networks. Magnetic properties of the CoIIFeIII complex studied by a SQUID magnetometer reveal low-temperature antiferromagnetic interaction.

4 citations


Journal ArticleDOI
TL;DR: In this paper, the synthesis, characterization, and magnetic properties of a new series of dinuclear compounds MIIMIIL2(H2O)4 (where MII, M′II = Mn (1), Ni (2), Cu (3) and MII
Abstract: Synthesis, characterization, and magnetic properties of a new series of dinuclear compounds MIIM′IIL2(H2O)4 (where MII, M′II = Mn (1), Ni (2), Cu (3) and MII = Cu, M′II = Co (4), Ni (5); LH2 = 2,5-bis(4-carboxyphenylamino)-3,6-dichloro-1,4-benzoquinone) are reported. These complexes were characterized by elemental analyses, FAB mass spectra, thermogravimetric analysis, spectroscopic techniques (infrared, NMR, UV-Vis), and powder XRD studies. Magnetic properties investigated by SQUID magnetometer show antiferromagnetic coupling between the metal centers connected by the extensive π-delocalized ligand. Magnetic coupling constants (J) ranging from −1.01 to −3.01 cm−1 based on the Hamiltonian H = −2JS i S j have been obtained. The optimized geometry of the ligand derived from DFT is also reported.

3 citations