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M R Prathapachandra Kurup

Publications and source records attributed to M R Prathapachandra Kurup.

13 recordsLinked to original sources

N-2-hydroxy-4-methoxyacetophenone-N'-4-nitrobenzoyl hydrazine: synthesis and structural characterization.

A new aroyl hydrazone, N-2-hydroxy-4-methoxyacetophenone-N'-4-nitrobenzoyl hydrazine was prepared by the condensation reaction of 2-hydroxy-4-methoxyacetophenone and 4-nitrobenzoyl hydrazine. Characterization of the compound was done by elemental analysis and electronic, infrared and NMR spectral analyses. The complete structural assignment of the compound was done by NMR studies by using COSY homonuclear and HSQC heteronuclear techniques. The crystal and molecular structure was determined by single crystal X-ray diffraction studies: crystallized in the monoclinic system, space group P2(1)/n, Z=4, a=7.3343(9)A, b=20.3517(9)A, c=10.1375(5)A, alpha=90.00 degrees, beta=95.735(7) degrees and gamma=90.00 degrees. From the crystal structure, it is concluded that the compound exists as the keto isomer in the solid state. There is a completely extended conformation in the central part of the molecule C5C8N1N2C10O2 with an E configuration at the double bond of the hydrazinic bridge.

Acetophenones↗

Spectral characterization and crystal structure of 2-benzoylpyridine nicotinoyl hydrazone.

The synthesis, spectral characterization and crystal structure of 2-benzoylpyridine nicotinoyl hydrazone (HL) is reported. Spectral techniques employed include 1H NMR, COSY homonuclear, HSQC heteronuclear correlation techniques, electronic and IR. The infrared spectrum suggests the existence of the compound in keto form in solid state, which is further established by the single crystal X-ray analysis. The compound crystallizes into a triclinic lattice with P-1 symmetry with two molecules per unit cell.

Crystallization↗

Spectral characterization of iron(III) complexes of 2-benzoylpyridine N(4)-substituted thiosemicarbazones.

Three iron(III) complexes (1-3) of 2-benzoylpyridine N(4)-phenyl thiosemicarbazone (HL1) and one iron(III) complex (4) of 2-benzoylpyridine N(4)-cyclohexyl thiosemicarbazone (HL2) were synthesized and characterized by means of different physicochemical techniques viz., molar conductivity measurements, magnetic susceptibility studies and electronic, infrared and EPR spectral studies. The analytical data and the molar conductance measurements of the complexes reveal that two molecules of the ligand and the anion are coordinated to the metal atom in all the four complexes. The magnetic moments of the complexes suggest that they are of low spin. From the infrared spectra of the ligands and the complexes it is confirmed that the ligands coordinate to iron(III) as an anion coordinating via the azomethine nitrogen, pyridyl nitrogen, and the thiolate sulphur. The EPR spectra of the complexes in the polycrystalline state at 298 and 110 K and in DMF solution at 110 K were recorded and all the spectra show three g values indicating that these complexes have rhombic distortion. All the iron(III) complexes in DMF solution at 110 K have similar anisotropic spectra with almost the same gav values, indicating that the bonding in all the complexes is similar and is unaffected by the coordination of the anion.

Electron Spin Resonance Spectroscopy↗

Structural and spectral perspectives of a novel thiosemicarbazone synthesized from di-2-pyridyl ketone and 4-phenyl-3-thiosemicarbazide.

A new thiosemicarbazone, HL is synthesized from di-2-pyridyl ketone and 4-phenyl-3-thiosemicarbazide and structurally and spectrochemically characterized. 1H NMR, 13C NMR, COSY, HMQC and IR spectra of the compound are studied and the proton magnetic resonance spectrum reveals some unprecedented observations. The thione form is predominant in the solid state, as supported by the crystal structure and IR data, while a thiol-thione equilibrium is proposed in the solution state by NMR studies. The compound crystallizes into a monoclinic lattice with space group C2/c and the ZE conformation is exhibited by the thiosemicarbazone. Intra- and intermolecular hydrogen-bonding interactions give rise to a two-dimensional packing in the crystal lattice.

Crystallography, X-Ray↗

Salicylaldehyde 4,4'-(hexane-1,6-diyl)thiosemicarbazone.

The title compound, C14H19N3OS, is in the thioketo form, with the thione S and hydrazine N atoms cis with respect to each other so that the S atom is involved in inter- and intramolecular hydrogen bonds simultaneously. Intermolecular C-H...S and C-H...O hydrogen bonds result in one-dimensional polymeric chains of molecules along the a axis. A weak C-H...pi ring interaction binds the polymeric chains together.

Aldehydes↗

[Di-2-pyridyl ketone N4,N4-(butane-1,4-diyl)thiosemicarbazonato-kappa3N,N',S]dioxovanadium(V).

The V(V) atom in the title complex, [V(C(16)H(16)N(5)S)O(2)], is five-coordinate in a highly distorted square-pyramidal geometry, with the pyridyl N, the azomethine N and the thiolate S atoms of the di-2-pyridyl ketone N(4),N(4)-(butane-1,4-diyl)thiosemicarbazone ligand and one oxo ligand occupying the basal coordination positions, while the second oxo ligand occupies the apical position. The molecules are interconnected by weak intermolecular interactions, mainly of the C-H...O type, involving the oxo atoms.

Journal Article↗

Bis(mu-phenyl 2-pyridyl ketone N4,N4-butane-1,4-diylthiosemicarbazonato)bis[chlorocopper(II)].

The title compound, [Cu2(C17H17N4S)2Cl2], exhibits a dimeric structure related by a centre of symmetry. The monomers are linked to each other by the longest Cu-S apical distance observed to date among Cu(II) square-pyramidal complexes of N4-substituted thiosemicarbazones. Each Cu(II) atom deviates from the coordination square plane, which contains the pyridyl and imine N atoms, the thiolate S atom and the Cl- anion, towards the S atom of the adjacent monomer. The dimers pack in a zigzag manner through the crystal.

Crystallization↗

Synthesis and spectral characterization of ternary complexes of oxovanadium(IV) containing some acid hydrazones and 2,2'-bipyridine.

An interesting series of heterocyclic base adducts of oxovanadium(IV) complexes have been synthesized by the reaction of vanadium(IV) oxide acetylacetonate with some hydrazones (H(2)L) in the presence of a heterocyclic base 2,2'-bipyridine. The compounds were characterized by analytical and different physico-chemical techniques like IR, electron paramagnetic resonance (EPR) and UV-Vis spectral studies and magnetic studies. The EPR spectra indicate that the free electron is in the d(xy) orbital. The coordination geometry around oxovanadium(IV) in all complexes is octahedral, with one dibasic tridentate ligand L(2-), and one bidentate heterocyclic base. The IR spectra suggest that coordination takes place through azomethine nitrogen and enolate oxygen from the hydrazide moiety and phenolate oxygen. The pyridyl nitrogens of the hydrazones, H(2)L(2) and H(2)L(4) are not involved in the coordination. The molar conductivities show that all the complexes are non-electrolytes. All electronic transitions were assigned. All the compounds are paramagnetic. EPR studies of all compounds suggest axial symmetry. The calculated bonding parameters indicate that in-plane sigma bonding is more covalent than in-plane pi bonding.

2,2'-Dipyridyl↗

Di-2-pyridyl ketone 4-methyl-4-phenylthiosemicarbazone.

The molecule of the title compound, C(19)H(17)N(5)S, adopts a Z configuration about the azomethine bond and exists as the thione tautomer. The overall structure of the molecule is distributed in four different planes. An intramolecular hydrogen bond involving the pyridyl N atom and the H atom attached to the hydrazine N atom leads to the formation of a six-membered ring.

Journal Article↗

2-Hydroxy-3-(4,5,6,7-tetrahydro-1H-imidazo[4,5-c]pyridin-5-ium-4-yl)benzoate monohydrate.

The title molecule, C(13)H(13)N(3)O(3).H(2)O, is in the form of a monohydrated zwitterion. The tetrahydropyridinium ring adopts an envelope conformation and is nearly coplanar with the plane of the imidazoline ring. The water solvate molecule plays an important role as a bridge between zwitterions, forming molecular chains running along the c direction, which are interconnected by N-H.O hydrogen bonds into molecular ribbons. The crystal packing is further stabilized by another N-H.O and one O-H.N hydrogen bond, which interconnect the molecular ribbons.

Journal Article↗

Di-2-pyridyl ketone N4,N4-(butane-1,4-diyl)thiosemicarbazone.

The title compound, C(16)H(17)N(5)S, is in the thione form and crystallizes with two independent molecules in the asymmetric unit. In both molecules, the pentamethyleneimine five-membered ring adopts an envelope conformation, and in one of the molecules this ring shows positional disorder. The thione S and hydrazine N atoms are in the Z configuration with respect to the C-N bond.

Journal Article↗

Bis[1-(pyridin-2-yl)ethanone-kappa N 4-phenylthiosemicarbazonato-kappa 2N4,S]manganese(II).

One half of the molecule of the title complex, [Mn(C(14)H(13)N(4)S)(2)], is related to the other half by a twofold axis passing through the Mn atom. This high-spin Mn atom is six-coordinated, in an octahedral geometry, by the azomethine N, the pyridyl N and the thiolate S atom of two planar 1-(pyridin-2-yl)ethanone N(4)-phenylthiosemicarbazone ligands. In the crystal, the molecules are interconnected by N-H.S and C-H.N interactions, forming a three-dimensional network.

Journal Article↗