Studies on crystals of d-, l-, and dl-alaninato nickel(II) complexes

Abstract

An attempt to link the heat of reaction obtained from analysis of UV spectra, bond energies deduced from crystallographic data and calorimetric measurements of [bis(D-, L-, and DL-alaninato)diaqua] nickel(II) dihydrate complexes to theoretical values obtained from calculation is described. The heat of reaction, which includes energy of ligand exchange in addition to crystal field stabilization energy of the three complexes, was calculated from changes in spectral shifts, bond lengths, and free energy between nickel(II) ion and the D-, L-, and DL-alanine complexed nickel(II) ion in aqueous solution. These investigations were done by UV-visible spectroscopy, X-ray crystallography, and isothermal calorimetry. The results reveal that the experimental heat of reaction based on the three mentioned parameters is in good agreement with the theoretical value. The results are found to be of considerable interest in its linking of spectrochemical quantities with thermodynamic functions.

Mixed Ligand Complexes of Co(II) and Ni(II) Containing Organic Acids and Amine Bases as Primary and Secondary Ligands

“…Amino acids form complexes with metal atoms and exhibit significant biological and enzymatic activities [2]. The synthesis, spectrochemical properties, structure, stability, thermochemical study, and characterization of complexes of Ni(II) with histidine, glycine, alanine, and other amino acids have previously been reported [3][4][5][6][7][8][9]. Standard molar enthalpies of formation of glycine and alanine in the gaseous phase on the basis of theoretical calculations have also been studied [10].…”