Estimation of Stability Constants of Copper(II) Complexes with α‐Amino Acids Using Connectivity Index 3χv. Common Model for the Binary and Ternary Complexes

Abstract

AbstractModels for estimation of the first (K1), second (K2), and overall stability constant (β2) of copper(II) chelates with naturally occurring amino acids, based on the valence connectivity index of the 3rd order (3χv), were improved by introduction of a square term and a new graph representation for mono‐complexes (MLcor). The models gave SE=0.07, 0.05–0.07 and 0.05–0.08 for lg K1, lg K2 and lg β2 constants, respectively; models that encompass both binary and ternary bis‐complexes included indicator variable. We also validated our models on the test set which included two mono‐, two binary and two ternary Cu(II) chelates with α‐aminobutanoic acid and α‐aminopentanoic acid, not included into the calibration. The absolute differences between experimental and predicted stability constants were in the range of 0.01–0.16.