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ISRN Physical Chemistry
Volume 2012 (2012), Article ID 260171, 11 pages
http://dx.doi.org/10.5402/2012/260171
Research Article

A QSPR Study for the Prediction of the pKa of N-Base Ligands and Formation Constant Kc of Bis(2,2′-bipyridine)Platinum(II)-N-Base Adducts Using Quantum Mechanically Derived Descriptors

1Physics Department, Faculty of Sciences and Arts, Harran University, Osmanbey, 63300 Sanliurfa, Turkey
2Chemistry Department, Faculty of Sciences and Arts, Harran University, Osmanbey, 63300 Sanliurfa, Turkey
3Primary Science Education Department, Faculty of Education, Akdeniz University, Dumlupinar Bulvari, 07058 Antalya, Turkey

Received 9 July 2012; Accepted 29 July 2012

Academic Editors: J. G. Han and W. P. Hu

Copyright © 2012 Selami Palaz et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Quantitative structure-property relationship (QSPR) study on the acid dissociation constant, pKa of various 22 N-base ligands including pyridines, pyrimidines, purines, and quinolines has been carried out using Codessa Pro methodology and software. In addition, the formation constant, Kc of these ligands with Pt(II) (bpy = 2,2′-bipyridine) ion has also been modelled with the same methodology. Linear regression QSPR models of pKa and Kc were established with descriptors derived from AM1 calculations. Among the obtained QSPR models of pKa presented in the study, statistically the most significant one is a four parameters linear equation with the squared correlation coefficient, values of ca. 0.95 and the squared cross-validated correlation coefficient, values of ca. 0.89, and external the squared correlation coefficient, values of ca. 0.97. Statistically the most significant QSPR model of Kc is also a four parameters linear equation with the squared correlation coefficient, values of ca. 0.75 and the squared cross-validated correlation coefficient, values of ca. 0.55, and external the squared correlation coefficient, values of ca. 0.81. An analysis of descriptors that involved in the pKa models indicate that reactivity index and charge distribution related descriptors play major roles to model acid dissociation constant of ligands of N bases.