Prediction of Stability Constants of Zinc(II) Complexes with 2-aminobenzamide and Amino Acids.

Ante Miličević,Nenad Raos

doi:10.17344/acsi.2015.1487

Ante Miličević, Nenad Raos

Open Access

https://doi.org/10.17344/acsi.2015.1487

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Abstract

We developed a model for the stability (log β(ZnLB)) of Zn(2+) mixed complexes (N = 16) with 2-aminobenzamide (L) and four amino acids (B) glycine, alanine, valine, and phenylalanine at 300, 310, 320, and 330 K. The model was based on the quadratic regression function of the molecular valence connectivity index of the third order, (3)χ(v), yielded S.E. = 0.02. We also developed an overall model for K(1), K(2) and β(ZnLB) of the same system at all of the four temperatures (N= 48). This model yielded S.E. = 0.05.

Highlights

Models based on graph theoretical indices rely on somewhat vague concepts, as do other models based on topological approaches in theoretical chemistry,[1,2] they have proved quite successful in many applications
Stability constants of copper(II) complexes with α-amino acids were reproduced with such a precision that it was even possible to evaluate the results of two electroanalytical methods (GEP and SWV) used for their measurement.[10]
In order to model the logarithm of stability constant, log βZnLB, (Eq 1, Table 1) of mixed Zn2+complexes with 2-aminobenzamide and amino acids (ZnLB), we used the quadratic function of 3χv (Figure 2): Table 1

Summary

Introduction

Models based on graph theoretical indices rely on somewhat vague concepts, as do other models based on topological approaches in theoretical chemistry,[1,2] they have proved quite successful in many applications. Graph theoretical indices correlate well with many physicochemical parameters[3,4,5,6] and biological activities (QSAR).[7,8] Our efforts to use topological indices, especially the valence connectivity index of the 3rd order, 3χv, in order to build regression models for the prediction of stability constants of coordination compounds[9] ended with varying success, depending on the nature of coordination compounds as well as on the quality of experimental data. Our method, despite being strictly empirical, enabled the analysis of coordination, i.e. it gave insight into the structure of the complex.[13,14] in other cases additional variables[15] and unusual forms of regression functions[16] had to be introduced in order to obtain an acceptable agreement between theory and experiment

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Conclusion