I.S. Ahuja

Complexes of copper(II) with nicotinic acid and some related ligands

SummaryCoordination compounds of copper(II) chloride, bromide, thiocyanate and sulphate with nicotinic acid, nicotinamide and isonicotinamide have been prepared and characterized by molecular conductance, magnetic susceptibility, electronic and i.r. spectral measurements down to 200 cm−1 in the solid state. Possible stereochemistries for these complexes in the solid state are discussed.

Uranyl nitrate and thiocyanate complexes with some pyridine N-oxides

Abstract The complexes formed by uranyl nitrate and thiocyanate with pyridine N-oxide, 2-methyl-, 3-methyl-, 4-methyl-; 2,6-dimethyl- and 4-cyano- pyridine N-oxides have been prepared. These complexes have been examined spectroscopically (down to 200 cm −1 ) in the solid state and the possible coordination arrangement around the metal atoms discussed.

2-, 3- and 4-cyanopyridine complexes with some zinc(II), cadmium(II) and mercury(II) salts

Abstract Complexes formed by some zinc(II), cadmium(II) and mercury(II) salts with 2-, 3- and 4-cyanopyridines have been prepared and characterized by molecular conductance and infrared spectral measurements down to 200 cm −1 . Possible structures for these complexes in the solid state are discussed.

STructural information on manganese(II), cobalt(II), nickeL(II), zinC(II) and cadmium(II) sulphate complexes with hexamethylenetetramine (a potentially tetradentate ligand) from their magnetic moments, electronic and infrared spectra

Abstract Coordination compounds formed by the interaction of hexamethylenetetramine (Hmta), a potentially tetradentate ligand, with manganese(II), cobalt(II), nickel(II), zinc(II) and cadmium(II) sulphates have been prepared and characterized from their elemental analyses, magnetic susceptibilities and electronic and infrared spectral studies down to 200 cm −1 in the solid state. The compounds isolated are: Mn(Hmta)SO 4 , Co(Hmta)SO 4 , Ni(Hmta)SO 4 , Zn(Hmta)SO 4 , and Cd(Hmta)SO 4 . It is shown that Hmta, though a potentially tetradentate ligand, acts only as a bidentate ligand bridging between two metal ions retaining the chair configuration of the uncoordinated molecule in all these complexes. Tentative stereochemistries of the complexes in the solid state are discussed. The ligand field parameters 10 Dq , B ,β and λ calculated for the manganese(II), cobalt(II) and nickel(II) complexes are consistent with their proposed stereochemistries.

2,2′-Bipyridylamine complexes with some zinc(II), cadmium(II) and mercury(II) salts

Abstract The complexes formed by some zinc(II), cadmium(II) and mercury(II) salts with 2,2′-bipyridylamine have been prepared and characterised by molecular conductance and infrared spectral measurements down to 200 cm −1 . Possible structures for these complexes in the solid state are discussed.

Electron spin resonance studies on some copper(II) complexes with a few nitrogen donors derived from pyridine

Abstract Electron spin resonance spectral studies have been made on copper(II) chloride, bromide, thiocyanate and sulphate complexes with some pyridine derivatives, viz. nicotinic acid (NA), nicotinamide (NICA) and isonicotinamide (INA) in solid and DMF-solution states to see the effect of different anions on the Spin-Hamiltonian parameters at the paramagnetic site for a particular ligand. The spectra of the complexes for a particular anion are almost comparable suggesting the same local symmetry for them. Analysis of the ESR data reveals axial symmetry for all the complexes, except Cu(NA) 2 SO 4 for which a rhombic symmetry is suggested. The study shows the interaction of solvent (DMF) molecules with copper(II) ion in the axial plane as evident from the differences in 295 and 77 K g | values. Moreover, the spectra are consistent with the complete absence or negligbly small copper(II)—copper(II) interactions (in few cases) in these complexes. The various Spin-Hamiltonian parameters calculated from ESR data indicate the presence of an unpaired electron in the d x 2 − y 2 orbital of the copper(II) ion with the additional possibility of a d xy ground state for Cu(NA) 2 SO 4 .

1,3-PROPANEDIAMINE, 1,4-BUTANEDIAMINE (PUTRESCINE) AND 1,5-PENTANEDIAMINE (CADAVERINE) COMPLEXES WITH ZINC(II), CADMIUM(II) AND MERCURY(II) HALIDES AND PSEUDOHALIDES

Abstract Coordination compounds formed by zinc(II), cadmium(II) and mercury(II) halides and pseudohalides with 1,3-propanediamine, 1,4-butanediamine (putrescine) and 1,5-pentanediamine (cadaverine) have been prepared and characterized by molecular conductance and infrared spectral measurements down to 200 cm−1. Possible structures for these complexes in the solid state are discussed.

Hexamethylenetetramine complexes with manganese(II), cobalt(II), nickel(II), copper(II), zinc(II) and cadmium(II) thiocyanates

Abstract Coordination compounds formed by the interaction of hexamethylenetetramine (Hmta), a potentially tetradentate ligand, with Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) thiocyanates have been prepared and characterized from their elemental analyses, magnetic susceptibilities, electronic and i.r. spectral studies down to 200 cm−1 as well as X-ray powder diffraction patterns in the solid state. The compounds isolated are: Mn(NCS)2(Hmta)2(EtOH)2, Mn(NCS)2(Hmta)2, Co(NCS)2(Hmta)2(EtOH)2, Co(NCS)2(Hmta)2, Ni(NCS)2(Hmta)2(EtOH)2, Ni(NCS)2(Hmta)2, Cu(NCS)2(Hmta)2, Zn(NCS)2(Hmta)2 and Cd(NCS)2(Hmta). It is shown that Hmta, though a potentially tetradentate ligand, acts only as a terminally bonded monodentate ligand or a bidentate ligand bridging between two metal atoms retaining the chair configuration of the uncoordinated molecule in all these complexes. The tentative stereochemistries of the complexes are discussed. The ligand field parameters 10 Dq, B, β, λ and ν2/ν1 calculated for the cobalt, nickel and copper complexes are consistent with their proposed stereochemistries.

Complexes of some bivalent cobalt, nickel, copper, zinc, cadmium and monovalent silver salts with 4,4′-BipyridylN,N′-dioxide

SummaryCoordination compounds have been prepared from 4,4′-hipyridylN,N′-dioxide (4,4′-BipyO2) and some hivalent metal halides, nitrates and thiocyanates as well as silver(1) nitrate.viz., Co(4.4′-BipyO2)2Cl2, Co(4.4′-BipyO2)Br2, Co(4,4′-Bi-pyO2)(NO3)2. Co(4,4′-BipyO2)2(NCS)2. Ni(4.4′-BipyO2)2Cl2. Ni(4,4′-BipyO2)(NO3)2, Ni2(4.4′-BipyO2)3(NSC)4. Cu(4,4′-BipyO2)(NO3)2. Zn(4,4′-BipyO2(NO3)2, Zn,(4.4′-BipyO2)3-(NCS)4. Cd(4.4′-BipyO2)(NO3)2, Cd(4.4′-BipyO2)2(NCS)2 and Ag(4,4′-BipyO2)(NO3). The products were characterized by magnetic susceptibility. electronic and i.r. spectral measurements down to 200 cm−1. Tentative stereochemistries for the complexes isolated in the solid state are proposed. The ligand field parameters 111 Dy. B. j3. )., and calculated for the cobalt. nickel and copper complexes are consistent with these stereochemistries.

Cadmium (II) nitrate complexes with some pyridine N-oxides

Abstract Coordination compounds formed by cadmium (II) nitrate with pyridine N-oxide, 2-methyl-, 3-methyl-, 4-methyl- and 2,6-dimethyl-pyridine N-oxides have been prepared and characterized by molecular weights and i.r. spectral measurements down to 200 cm −1 in the solid state. Possible structures for these complexes in the solid state are discussed.