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On a new semi‐empirical electrotopological index for QSRR models
Author(s) -
Souza Érica Silva,
Kuhnen Carlos Alberto,
Junkes Berenice da Silva,
Yunes Rosendo Augusto,
Heinzen Vilma Edite Fonseca
Publication year - 2008
Publication title -
journal of chemometrics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.47
H-Index - 92
eISSN - 1099-128X
pISSN - 0886-9383
DOI - 10.1002/cem.1142
Subject(s) - mulliken population analysis , chemistry , quantitative structure–activity relationship , topological index , kovats retention index , partial charge , atom (system on chip) , atomic charge , carbon fibers , carbon atom , quantum chemistry , basis set , computational chemistry , thermodynamics , molecule , organic chemistry , density functional theory , stereochemistry , chromatography , gas chromatography , mathematics , algorithm , physics , alkyl , supramolecular chemistry , embedded system , composite number , computer science
A new semi‐empirical electrotopological index, I SET , for quantitative structure–retention relationships (QSRR) models was developed based on the refinement of the previously published semi‐empirical topological index, I ET . We demonstrate that the values of C i fragments that were firstly attributed from the experimental chromatographic retention and theoretical deductions have an excellent relationship with the net atomic charge of the carbon atoms. Thus, the values attributed to the vertices in the hydrogen‐suppressed graph of carbon atoms ( C i ) are calculated from the correlation of the net atomic charge in each carbon atom, which is obtained from quantum chemical semi‐empirical calculations, and the C i fragments for primary, secondary, tertiary and quaternary carbon atoms (1.0, 0.9, 0.8 and 0.7, respectively) obtained from the experimental values. This shows that I ET encoded this quantum physical reality and that it is possible to calculate a new I SET (the semi‐empirical electrotopological index) through the net atomic charge values obtained from a Mulliken population analysis using the semi‐empirical AM1 method and their correlation with the values attributed to the different types of carbon atoms. This demonstrates that the I SET encodes information on the charge distribution of the solute on which dispersive and electrostatic interactions between the solute (alkanes and alkenes) and the stationary phase strongly depend. Thus, this new method can be considered as an initial step towards forthcoming QSRR/QSAR studies. Copyright © 2008 John Wiley & Sons, Ltd.