Homogeneous isotopic exchange between nickel(II) and bis(diethyldithiocarbamato)nickel(II) complex

Isotopic exchange behaviour of bis(diethyldithio carbamate) nickel(II) complex with nickel(II) in chloroform and methanol medium was studied. The studies were carried out at different temperatures varying the concentration of both metal ion and the complex. The results show that the complex is labile in the kinetic sense. Increase in temperature increases the isotopic exchange rate. The increase in concentration also results in enhancement of the rate of reaction.     

Homogeneous isotopic exchange between nickel(II) and bis(resacetophenone oxime) nickel(II) complex

Isotopic exchange behaviour of bis(resacetophenone oxime) nickel(II) complex with nickel(II) in tri-n-butyl phosphate (TBP) and ethanol medium has been studied. The studies were carried out at different temperatures by varying the concentrations of both metal ion and the complex. Experimental observations showed that the complex is kinetically labile. Increase in temperature increases the isotopic exchange rate. Increase in concentration of either metal ion or complex results in significant increase of the reaction rate.     

Molecular motions in the solid state: the thermochromic nitro-nitrito Interconversion in nickel(II) bis(diamine) complexes

The NO(2)(-) ion, in the trans-octahedral [Ni(II)(N,N'-dimethylethylenediamine)(2)(NO(2))(2)](H(2)O) complex, coordinates the metal through the nitrogen atom (nitro form). On heating the solid complex, the anion rotates to give nitrito coordination (oxygen bound), according to a reversible process. The coordination mode of NO(2)(-) to Ni(II) is related to the steric interplay between the anion and the alkyl substituents on the diamine.     

Homogeneous isotope exchange between nickel(II) and bis(resacetophenone phenylhydrazone) nickel(II) complex

Isotope exchange behavior of bis-resacetophenone phenylhydrazone) nickel(II) complex with nickel(II) in tri-n-butyl phosphate and methanol medium has been studied. The studies were carried out at different temperatures varying the concentration of both metal ion and the complex. The results show that the complex is labile in the kinetic sense. Increase in temperature increases the isotope exchange rate. The increase in concentration also results in an enhancement of the rate of reaction.     

Hexaaquacobalt(II) bis(hypophosphite) and hexaaquacobalt(II)/nickel(II) bis(hypophosphite)

The title compounds, hexa­aqua­cobalt(II) bis­(hypophosphite), [Co(H₂O)₆](H₂­PO₂)₂, and hexa­aqua­cobalt(II)/nickel(II) bis(hypophosphite), [Co_0.5Ni_0.5(H₂O)₆](H₂PO₂)₂, are shown to adopt the same structure as hexa­aqua­magnesium(II) bis­(hypophosphite). The packing of the Co(Ni) and P atoms is the same as in the structure of CaF₂. The Co^II(Ni^II) atoms have a pseudo‐face‐centred cubic cell, with a = b～ 10.3 Å, and the P atoms occupy the tetrahedral cavities. The central metal cation has a slightly distorted octahedral coordination sphere. The geometry of the hypophosphite anion in the structure is very close to ideal, with point symmetry mm2. Each O atom of the hypophosphite anion is hydrogen bonded to three water mol­ecules from different cation complexes, and each H atom of the hypophosphite anion is surrounded by three water mol­ecules from further different cation complexes.     

Crystal structure of bis(iso-maleonitril-edithiolate)nickel(II) benzylpiperidinium

Bis(iso-maleonitriledithiolate)nickel(II) benzylpiperidinium, [BzPid]₂[Ni(i-mnt)₂] (1) is prepared and characterized by elemental analyses, UV, IR, molar conductivity, and single crystal X-ray diffraction. It is found that 1 crystallizes in the monoclinic space group P2₁/n with a = 9.551(1) Å, b = 16.520(2) Å, c = 11.004(1) Å, β = 96.60(1)°, V = 1724.6(3) ų, Z = 2. Consolidate the stacking of the molecules The electrostatic interaction between [Ni(i-mnt)₂]^2? anions and [BzPid]⁺ cations consolidates the stacking of the molecules.     

Simple non-empirical calculations of the zero-field splitting in bis(aquo) bis(malonato) nickel(II)

Summary A simple non-empirical method is applied to calculate the splittings of the ground state triplet, caused by the spin-orbit coupling, in bis(aquo) bis(malonato) nickel(II), allowing for a certain geometry variation. The calculations yield splittings on the order of 10–20 cm^–1. The comparison of exact (within model) and second-order perturbation theory calculations indicate that the spin Hamiltonian formalism is valid. The implications of the results for the theory of nuclear spin relaxation in paramagnetic complexes in solution are discussed.