Rapheal,P F; Manoj, E; Prathapachandra Kurup, M R(Elsevier, 2007)
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Abstract:
Ten copper(II) complexes {[CuL1Cl] (1), [CuL1NO3]2 (2), [CuL1N3]2 · 2/3H2O (3), [CuL1]2(ClO4)2 · 2H2O (4), [CuL2Cl]2 (5), [CuL2N3] (6), [Cu(HL2)SO4]2 · 4H2O (7), [Cu(HL2)2] (ClO4)2 · 1/2EtOH (8), [CuL3Cl]2 (9), [CuL3NCS] · 1/2H2O (10)} of three NNS donor thiosemicarbazone ligands {pyridine-2-carbaldehyde-N(4)-p-methoxyphenyl thiosemicarbazone [HL1], pyridine-2-carbaldehyde-N(4)-2-phenethyl thiosemicarbazone [HL2] and pyridine-2-carbaldehyde N(4)-(methyl), N(4)-(phenyl) thiosemicarbazone [HL3]} were synthesized and physico-chemically characterized. The crystal structure of compound 9 has been determined by X-ray diffraction studies and is found that the dimer consists of two square pyramidal Cu(II) centers linked by two chlorine atoms.
Prathapachandra Kurup, M R; Manoj, E; Rohith, John P; Nethaji, M; Alex, Punnoose(Elsevier, July 16, 2009)
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Abstract:
An unusual copper(II) complex [Cu(L1a)2Cl2] CH3OH H2O H3O+Cl (1a) was isolated from a solution of a
novel tricopper(II) complex [Cu3(HL1)Cl2]Cl3 2H2O (1) in methanol, where L1a is 3-(2-pyridyl)triazolo
[1,5-a]-pyridine, and characterized with single crystal X-ray diffraction study. The tricopper(II) complex
of potential ligand 1,5-bis(di-2-pyridyl ketone) carbohydrazone (H2L1) was synthesized and physicochemically
characterized, while the formation of the complex 1a was followed by time-dependant monitoring
of the UV–visible spectra, which reveals degradation of ligand backbone as intensity loss of bands
corresponding to O?Cu(II) charge transfer
Prathapachandra Kurup, M R; Alex, Punnoose; Manoj, E(Elsevier, October 17, 2008)
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Abstract:
Ten new copper(II) complexes of five potential bisthiocarbohydrazone and biscarbohydrazone ligands
were synthesized and physico-chemically characterized. The spectral and magnetic studies of compounds
are consistent with the formation of asymmetric di-, tri- or tetranuclear copper(II) complexes of deprotonated
forms of respective ligands. The variable temperature magnetic susceptibility measurements of all
complexes showantiferromagnetic interactions between the Cu(II) centers, in agreement with very broad
powder EPR spectra. However, frozen solution EPR spectral studies are found in contradiction with the
solid-state magnetic studies and indicate that the complexes are not very stable in solutions; the possible
fragmentations of complexes are found in agreement with MALDI MS results. The EPR spectral simulation
of most of the compounds is in agreement with the presence of two uncoupled Cu(II) species in solution.