Showing papers by "Bachcha Singh published in 1999"
TL;DR: In this paper, the copper(n) complexes of the type [CuSO4(L)(H2O)2] were characterized by elemental analyses, dehydration studies, molar conductance, magnetic moments, electronic, ESR and infrared spectra.
Abstract: The copper(n) complexes of the type [CuSO4(L)(H2O)2].nH2O and [CuSO4(L1)].nH2O where L = acetophenone-benzoylhydrazone (ABH), isonicotinoylhydrazone (AINH), -salicyloylhydrazone (ASH), -p-aminobenzoyl (APABH) and L1 = acetophenone oxaloyldihydrazone (AODH), -malonoyl-dihydrazone (AMDH) and -succinoyldihydrazone (ASDH) and n = 0, 1 or 2, were prepared and characterized by elemental analyses, dehydration studies, molar conductance, magnetic moments, electronic, ESR and infrared spectra. The electronic and ESR spectra indicate a six-coordinate distorted octahedral geometry for all of the complexes in the solid state. ESR spectral data reveal an axial symmetry for the ABH, AINH and APABH complexes whereas the AODH, AMDH and ASDH complexes are isotropic. Most of the ligands are bidentate, coordinating through the >C[dbnd]O and >C[dbnd]N groups to the metal ion except AMDH and ASDH which act as quadridentate ligands bonding through two >C[dbnd]O and two >C[dbnd]N groups.
14 citations
TL;DR: In this paper, the chelating behavior of neutral N-salicylidene-2-aminobenzophenone-2, thenoylhydrazone (H2sabth) and deprotonated sabth has been investigated in the complexes of the types VO(Sabth), SO4, M(Sabath)Cl2, VO(SO4), VO(sabath), and MSAth, SO4 [M = Mn(II), Co(II, Ni), Ni, and Cu(II)].
Abstract: The chelating behaviour of neutral N-salicylidene-2-aminobenzophenone-2-thenoylhydrazone (H2sabth) and deprotonated sabth has been investigated in the complexes of the types VO(H2sabth)SO4, M(H2sabth)Cl2, VO(sabth) and M(sabth)(H2O)2 [M = Mn(II), Co(II), Ni(II) and Cu(II)]. The complexes have been characterized by elemental analyses, molar conductance, magnetic susceptibility, cyclic voltammetry, F.SR, electronic and IR spectral studies. The stereochemistry of the complexes is discussed.
1 citations
TL;DR: In this article, the magnetic susceptibility, IR and electronic spectra of the complexes were employed to establish the stereochemistry and mode of bonding of the hydrazones of 2-furoylhydrazone.
Abstract: Complexes having the chemical compositions Fc(HL)2Cl2 [Hi. = 2-acetylthiophene-2-furoylhydrazone (Hatfh), 2-acetylfuran-2-furoylhydrazone (Haffh), 2-acetylpyridine-2-furoylhydrazone (Hapfh)]; Fe(Hhafh)Cl(H2O) [H2hafh - o-hydroxyacetophenonc-2-furoylhydrazone); [Fe(II2dapfh)Cl]Cl [H2dapfh 2, 6-diacetylpyridinc bis(2-furoylhydrazone)]; FeL2(H2O)n [HL = Hatfh, Haffh, n = 2; L = Hapfh. n = 0]; Fe(hafh)(H2O)3 and Fe(dapfh)(H2O) have been prepared and characterized. The electrical conductivity indicates a non-ionic nature of the complexes except [Fe(H2dapfh)Cl]Cl which is a 1:1 electrolyte in solution. Magnetic susceptibility, IR and electronic spectra of the complexes were employed to establish the stereochemistry and mode of bonding of the hydrazones. Mossbauer spectra indicate that iron is in the +2 oxidation state in these complexes.
1 citations
Journal Article•
Journal Article•
TL;DR: The reaction of triethylene tetra amine and di et hyl oxalate yie ld a 12-membered macrocycle is described in this article, where the symmetry of th e ligand fi eld around the metal ions is indicated from the ion spectra.
Abstract: The reaction of triethylene tetra amine and di et hyl oxalate yie ld a 12-membered macrocycle. The co mplexes [Ln(tadd)CI 2(H 20h]CI (Ln(lII) = La, Pr, Nd, Sm, Eu , Gd, Tb and Dy; tadd = 1,4,7,1 O-tetraazacyclo dodecane-2, 3-d ione) have been sy nthesized by te mpl ate reacti(')n of the lanthanide ion. The complex [La(tadd)Cl 2(H 20 )2]CI react s with lanthanide ch lorides to yie l.d th e complexes of type [2{La( tadd)CI2(H20h}LnCI3(H20)2]CI2. The chemical compositions of both th e mono and trimetallic co mpl exes · have bee n establi shed from anal ytical, molar co nductance and FAB mass data. It is obse rved th at the macrocyd e is bonded in tetraki s fashion in the former complexes and hexaki s in the latter. Th e coordin ation number eight aro und the encapsul ated metal ion s and nin e around the exocycli c oxygen bonded metal ions are es tablished from IR and electronic spectra. The symmetry of th e ligand fi eld around the metal ions is indicated from th e emi ss ion spectra.
TL;DR: In this paper, the symmetry of the ligand field around the metal ions is indicated from the emission spectra, and the chemical compositions of mono and trinuclear complexes are established on the basis of analytical, molar conductance, electrospray (ES) and fast atom bombardment (FAB) mass data.
Abstract: The reaction of 1,8-diamino-3,6-diazaoctane and diethyl malonate in dry methanol yielded a 13-membered macrocycle. Complexes of the type [Ln(tatd)Cl2 (H2O)3]Cl [LnIII=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy; tatd=1, 5, 8, 11-tetra-azacyclotridecane-2,4-dione] have been synthesized by template condensation. The complex [La(tatd)Cl2 (H2O)3]Cl in methanol was reacted with lanthanide chlorides to yield the trinuclear complexes of type [2{La(tatd)Cl2(H2O)3}LnCl3]Cl2 [LnIII=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy]. The chemical compositions of mono and trinuclear complexes have been established on the basis of analytical, molar conductance, electrospray (ES) and fast atom bombardment (FAB) mass data. In mononuclear complexes the Ln3+ ion is encapsulated by four ring nitrogens and in trimetallic complexes the exo-carbonyl oxygens of two mononuclear units coordinate to the Ln3+ ions resulting in a polyhedron around the lanthanide ions. Thus the macrocycle is bonded in a tetradentate fashion in the former complexes and hexadentate in the latter. The coordination number nine around the encapsulated Ln3+ and seven around the exo-oxygen bonded Ln3+ ions are established. The symmetry of the ligand field around the metal ions is indicated from the emission spectra.