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• 719261-06-0 nickel(II) carbonate 
• 56-40-6 glycine 

Relevant academic research and scientific papers

Potentiometric and Calorimetric Studies on Formation of Glycinato Complexes of Nickel(II) in Water and in an Aqueous Dioxane Solution

Protonation equilibria of glycinate (gly-) ion complex formation equlibria between nickel(II) and glycinate ions have been studied by potentiometry and calorimetry in water and in 0.2 mole fraction (55.0percentw/w) dioxane-water mixture, each containing 3 mol dm-3 LiClO4 as a constant ionic medium at 25 deg C.A series of mononuclear complexes, n>(2-n)+ (L = gly- and n=1-3) were found in both solutions and their formation constants, enthalpies and entropies were determined.It elucidated that the stepwise Gibbs energies of formation of the metal complexes varied in the sequence, ΔG01 02 03, and the stepwise enthalpies, ΔH01 > ΔH02 > ΔH03, and thus, the stepwise entropies markedly decreased in the order, ΔS01 > ΔS02 > ΔS03.The result was discussed in relation to changes in the metal-water and metal-ligand bond lengths within n(H2O)6-2n>(2-n)+ (n = 1-3) with n.As to the solvent effects, the formation constants of each metal complex increased with the addition of dioxane to water, the increase was caused by both enthalpies and entropies of formation of the complexes, the former mainly contributing to the formation of and the latter to + and -.The Gibbs energies of transfer of single species from water to the dioxane-water mixture were also evaluated.The enthalpy and entropy of transfer of any ionic species mostly compensated each other, so that the Gibbs energies of transfer of ions were rather small.

Fourier transform infrared spectrum, vibrational analysis and structural determinations of the trans-bis(glycine)nickel(II) complex by means of the RHF/6-311G and DFT:B3LYP/6-31G and 6-311G methods

The trans-bis(glycine)nickel(II) complex was synthesized, and the Fourier transform infrared spectra in the regions 4000-370 cm-1 and 700-30 cm-1 were measured. Band deconvolution analysis and the second derivative of the infrared spectrum were also performed. The determination of the geometrical structure in the trans position of the glycine ligands around Ni(II) for the trans-bis(glycine)nickel(II) complex as well as the vibrational assignment were assisted by RHF/6-311G and by Density Functional Theory calculations, DFT:B3LYP/6-31G and 6-311G basis sets. A full discussion of the framework vibrational modes was done using as criteria the geometry study of distorted structures generated for the vibrational modes. Incidentally, Normal Coordinate Analysis was carried out for the Ni(N)2(O)2 structural fragment. The calculated DFT spectra in the high- and low-energy regions agree with the observed ones.

ENTHALPIES OF TRANSFER OF SINGLE IONS AND METAL COMPLEXES FROM WATER TO AN AQUEOUS DIOXANE SOLUTION.

Enthalpies of solution of some 1:1 and 2:1 electrolytes were determined in water and in a dioxane-water mixture (the dioxane content; 0. 2 mole fraction or 55. 0% w/w) by calorimetry at 25 degree C. Enthalpies of transfer ( DELTA H//t**o) of single ions from water to the dioxane-water mixture were obtained by employing the extrathermodynamic tetraphenylarsonium tetraphenylborate (TATB) assumption. The enthalpies of transfer of the metal complexes examined increased almost linearly with an increase in the number of the ligands within the complexes.