P.C. Jain

Ligational behaviour of 4-benzylamidothiosemicarbazide: Complexes of ruthenium(III), rhodium(III), palladium(II), osmium(VIII) and platinum(IV)

Abstract Complexes of Ru(III), Rh(III), Pd(II), Os(VIII) and Pt(IV) with 4-benzylamidothiosemicarbazide have been isolated and characterized. The magnetic and electronic spectral data show that the ruthenium(III), rhodium(III) and platinum(IV) complexes have pseudo-octahedral symmetry while the palladium(II) forms complex conforming the square-planar geometry. The ruthenium(III) complex reveals the anomalous magnetic behaviour which may possibly be attributed to a large spin-orbit coupling. Relevant ligand field parameters, wherever possible, have been evaluated. The IR spectral studies indicate the SN-bidentate nature of the ligand.

Rare earth chelates of α,β-unsaturated-β-ketoamines

Abstract A series of trivalent lanthanide chelates of α,β-unsaturated-β ketoamines, Ln(apo)3.H2O, Ln(mapo)3.H2O and Ln(anpo)3.H2O, where, Ln = La, Ce, Pr, Sm, Nd, Gd and Dy; apo = 4-amino-3-pentene-2-one; mapo = 4-methylamino-3-pentene-2-one, and anpo = 4-anilino-3-pentene-one, have been prepared and characterized by analyses, magnetic and spectral studies. The magnetic moment values of the new complexes show little deviation from Van Vleck values. The infrared study establishes the coordination of the ligand to the metal ions through the nitrogen and oxygen atoms.

Platinum metal complexes of 8-amino-7-hydroxy-4-methylcoumarin with osmium(VIII), osmium(IV) and platinum(IV)

Abstract Complexes of Os(VIII), Os(IV) and Pt(IV) with 8-amino-7-hydroxy-4-methyl-coumarin have been isolated and characterised. Magnetic, conductivity and electronic spectral data show that all the complexes have octahedral geometries. The osmium-(IV) complex reveals an anomalous magnetic behaviour which may possibly be attributed to a large spin-orbit coupling. Relevant ligand field parameters have been evaluated where possible. I.R. spectral studies have also been made.

Correlation in magnetic and spectral studies on cobaltous complexes of 8-amino-7 hydroxy-4 methylcoumarin

Abstract 8-Amino-7 hydroxy-4 methylcoumarin (AHMC) has been found to form two distinct complexes with cobalt(II), viz. Co[(C 10 H 8 NO 3 ) 2 (H 2 O) 2 ] H 2 O and Co[(C 10 H 8 NO 3 ) 2 (NH 3 ) (H 2 O)] 3H 2 O at pH 8·5 and 12·0 respectively. Magnetic studies on powder form of these complexes reveal rather low values of magnetic moment for high-spin octahedral complexes, a possible correlation of which has been sought in nephelauxetic ratio of these complexes. Other ligand field parameters have also been evaluated. The i.r. spectra of the complexes have been discussed.

Metal complexes of 8-amino-7-hydroxy-4-methylcoumarin. I. Chromium(III), iron(III), cobalt(III), nickel(II) and copper(II) complexes

8-Amino-7-hydroxy-4-methylcoumarin has been found to form distinct coloured complexes with CrIII, FeIII, CoIII, NiII, and CuII metal ions. These complexes have been isolated and characterized by analyses, magnetic, electronic and infrared spectral studies. All the complexes are octahedral except the copper(II) complex which has square planar stereochemistry. The values of splitting energy, ligand field stabilization energy, Racahs parameters and nephelauxetic ratio, have been evaluated in most of the cases. Iron(III) complex is trimeric in nature involving chlorine bridges as evidenced by i.r. studies. Also these studies indicate the coordination of ligand through nitrogen atom. The stability order for metal ions has been drawn on the basis of νassym(NH2) vibrations.