Prathapachandra Kurup, M R; Reena, T A(Elsevier, March 15, 2010)
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Abstract:
Five copper(II) complexes [CuLCl]2·CuCl2·4H2O (1), [CuLOAc] (2), [CuLNO3]2 (3), [CuLN3] (4) and
[CuLNCS]·3/2H2O (5) of di-2-pyridyl ketone-N4-phenyl-3-semicarbazone (HL) were synthesized and
characterized by elemental analyses and electronic, infrared and EPR spectral techniques. In all these
complexes the semicarbazone undergoes deprotonation and coordinates through enolate oxygen, azomethine
and pyridyl nitrogen atoms. All the complexes are EPR active due to the presence of an unpaired
electron. EPR spectra of all the complexes in DMF at 77K suggest axial symmetry and the presence of
half field signals for the complexes 1 and 3 indicates dimeric structures
Description:
Spectrochimica Acta Part A 76 (2010) 322–327 doi:10.1016/j.saa.2010.03.011
Prathapachandra Kurup, M R; Suma, S; Sudarsana Kumar, M R; Siji, V L(Elsevier, February 26, 2010)
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Abstract:
Eight new transition metal complexes of benzaldehyde-N(4)–phenylsemicarbazone have been synthesized
and characterized by elemental analyses, molar conductance, electronic and infrared spectral
studies. In all the complexes, the semicarbazone is coordinated as neutral bidentate ligand. 1H NMR
spectrum of [Zn(HL)2(OAc)2] shows that there is no enolisation of the ligand in the complex. The magnetic
susceptibility measurements indicate that Cr(III), Mn(II), Fe(III), Co(II) and Cu(II) complexes are
paramagnetic and Ni(II) is diamagnetic. The EPR spectrum of [Mn(HL)2(OAc)2] in DMF solution at 77K
shows hyperfine sextet with low intensity forbidden lines lying between each of the two main hyperfine
lines. The g values calculated for the [Cu(HL)2SO4] complex in frozen DMF, indicate the presence of
unpaired electron in the dx2−y2 orbital. The metal ligand bonding parameters evaluated showed strong
in-plane bonding and in-plane bonding. The ligand and complexes were screened for their possible
antimicrobial activities.
Description:
Spectrochimica Acta Part A 76 (2010) 22–28 doi:10.1016/j.saa.2010.02.035
Prathapachandra Kurup, M R; Reena, T A(Springer, May 30, 2010)
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Abstract:
A new semicarbazone, HL has been synthesized
from quinoline-2-carboxaldehyde and N4-phenyl-3-
semicarbazide and structurally and spectrochemically
characterized. 1H NMR, 13C NMR, IR and electronic
spectra of the compound are studied. The existence of keto
form in the solid state is supported by the crystal structure
and IR data. The compound crystallizes into an orthorhombic
space group P212121. Intra and intermolecular
hydrogen bonding interactions facilitates unit cell packing
in the crystal lattice
Description:
J Chem Crystallogr (2010) 40:927–932
DOI 10.1007/s10870-010-9765-z
Prathapachandra Kurup, M R; Binu, Varghese; Sithambaresan, M; Suja, Krishnan; Sheeja, S R; Eringathodi, Suresh(Elsevier, 2011)
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Abstract:
An interesting series of nine new copper(II) complexes [Cu2L2(OAc)2] H2O (1), [CuLNCS] ½H2O (2), [CuLNO3]
½H2O (3), [Cu(HL)Cl2] H2O (4), [Cu2(HL)2(SO4)2] 4H2O (5), [CuLClO4] ½H2O (6), [CuLBr] 2H2O (7),
[CuL2] H2O (8) and [CuLN3] CH3OH (9) of 2-benzoylpyridine-N(4)-phenyl semicarbazone (HL) have been
synthesized and physico-chemically characterized. The tridentate character of the semicarbazone is
inferred from IR spectra. Based on the EPR studies, spin Hamiltonian and bonding parameters have been
calculated. The g values, calculated for all the complexes in frozen DMF, indicate the presence of the
unpaired electron in the dx2 y2 orbital. The structure of the compound, [Cu2L2(OAc)2] (1a) has been
resolved using single crystal X-ray diffraction studies. The crystal structure revealed monoclinic space
group P21/n. The coordination geometry about the copper(II) in 1a is distorted square pyramidal with
one pyridine nitrogen atom, the imino nitrogen, enolate oxygen and acetate oxygen in the basal plane,
an acetate oxygen form adjacent moiety occupies the apical position, serving as a bridge to form a centrosymmetric
dimeric structure