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ABSTRACT: Palladium(II), platinum(II), ruthenium(III) and iridium(III) complexes of general stoichiometry [PdL]Cl(2), [PtL]Cl(2), [Ru(L)Cl(2)]Cl and [Ir(L)Cl(2)]Cl are synthesized with a tetradentate macrocyclic ligand, derived from 2,6-diaminopyridine with 3-ethyl 2,4-pentanedione. Ligand was characterized on the basis of elemental analyses, IR, mass, and (1)H NMR and (13)C NMR spectral studies. All the complexes were characterized by elemental analyses, molar conductance measurements, magnetic susceptibility measurements, IR, mass, electronic spectral techniques and thermal studies. The value of magnetic moments indicates that all the complexes are diamagnetic except Ru(III) complex which shows magnetic moments corresponding its one unpaired electron. The macrocyclic ligand and all its metal complexes were also evaluated in vitro against some plant pathogenic fungi and bacteria to assess their biocidal properties.
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 02/2011; 78(5):1507-14. · 2.10 Impact Factor
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ABSTRACT: The lanthanide complexes derived from (3,5,13,15-tetramethyl 2,6,12,16,21-22-hexaazatricyclo[15.3.I(1-17)I(7-11)]cosa-1(21),2,5,7,9,11(22),12,15,17,19-decane) were synthesized. The complexes were found to have general composition [Ln(L)X(2).H(2)O]X, where Ln=La(3+), Ce(3+), Nd(3+), Sm(3+) and Eu(3+) and X=NO(3)(-) and Cl(-). The ligand was characterized by elemental analyses, IR, Mass, and (1)H NMR spectral studies. All the complexes were characterized by elemental analyses, molar conductance measurements, magnetic susceptibility measurements, IR, Mass, electronic spectral techniques and thermal studies. The ligand acts as a hexadentate and coordinates through four nitrogen atoms of azomethine groups and two nitrogen of pyridine ring. The lanthanum complexes are diamagnetic while the other Ln(III) complexes are paramagnetic. The spectral parameters i.e. nephelauxetic ratio (beta), covalency factor (b(1/2)), Sinha parameter (delta%) and covalency angular overlap parameter (eta) have been calculated from absorption spectra of Nd(III) and Sm(III) complexes. These parameters suggest the metal-ligand covalent bonding. In the present study, the complexes were found to have coordination number nine.
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 02/2010; 75(2):835-40. · 2.10 Impact Factor
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ABSTRACT: In the present paper, the lanthanide complexes derived from (1,5,8,12-tetraaza-2,4,9,11-tetramethyl cyclotetraaza-1,4,8,11-tetraene) were synthesized. The general composition of the complexes is [Ln(L)X 2 .H 2 O]X, where Ln = La, Ce, Nd, Sm and Eu and X = NO 3 – and Cl – . The ligand was characterized on the basis of elemental analyses, IR, Mass and 1 H NMR spectral studies. All the complexes were characterized by elemental analyses, molar conductance measurements, magnetic susceptibility measurements, IR, Mass, electronic spectral techniques and thermal studies. The ligand acts as a tetradentate chelate and coordinates through four nitrogen atoms of azomethine groups. The lanthanum complexes are diamagnetic while the other Ln III complexes are paramagnetic due to the presence of 4f n unpaired electrons. The spectral parameters i.e. nephelauxetic effect (β), covalency factor (b 1/2), Sinha parameter (δ%) and covalency angular overlap parameter (η) have been calculated from absorption spectra of Nd III and Sm III complexes. These parameters suggest the metal-ligand covalent bonding. In the present study, the complexes show the coordination number seven.
J. Indian Chem. Soc. J. Indian Chem. Soc. 09/2008; 85(85):783-791.
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ABSTRACT: Palladium(II) and platinum(II) complexes having the general composition [M(L)] X2 (where M=Pd(II) and Pt(II), L=3,4,12,13-tetraphenyl-2,5,11,14,19,20-hexaaza tricyclo [13.3.1.1.(6-10)] cosa-1(19), 2,4,6,8,10,(20),11,13,15,17-decaene (L1); 3,4,13,14-tetraphenyl-2,5,12,15-tetraaza tricyclo [11,0,0,(6-11)] cosa-1(16),2,4,7,9,6(11),12,14,17, 19-decaene (L2); 2,3,8,9-tetraphenyl-1,4,7,10-tetraaza cyclododeca-1,3,7,9-tetraene (L3) and X=Cl(-)) have been synthesized. The ligands were characterized on the basis of elemental analyses, IR, 1H NMR and EI mass spectral studies while that of the complexes were characterized on the basis of elemental analyses, molar conductance measurements, magnetic susceptibility measurements, IR, and electronic spectral techniques. All the complexes were found to be diamagnetic. The structures consist of monomeric units in which the Pd(II) and Pt(II) atoms exhibit square planar geometry.
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 03/2008; 71(2):720-4. · 2.10 Impact Factor
