Estimation of Stability of Cadmium(II) Mono-Complexes with Monodentate and Bidentate Ligands by Models Based on 3χv Connectivity Index

Based on the quadratic function used previously for the estimation of copper(H) amino acid mono-complexes, we developed the model for the estimation of the stability constant K-1 of cadmium(II) complexes with five amino acids (glycine, alanine, 2-aminobutanoic, 2-aminopentanoic, and 2-aminohexanoic acid). The model gave R-2 = 0.960 and S.E. = 0.03. Also, for the first time we proposed (univariate linear) model for the estimation of K-1 of complexes with monodentate ligands, namely the Cd(II) complexes with methanoic, ethanoic, propanoic, 2-methylpropanoic, butanoic, 2-methylbutanoic, 2-hydroxyethanoic, 2-hydroxypropanoic and 2-hydroxybutanoic acid. The model is capable to discriminate monodentate from bidentate ligands; much better statistic was obtained (R-2 = 0.966 and S.E. = 0.05) if 2-hydroxybutanoic acid was assumed to be bidentate.