A comparative Study of Molecular Lipophilicity Indices of Some Formyl- and Acetylpyridine-3-Thiosemicarbazone Derivatives and Various Computed Descriptors
A comparative Study of Molecular Lipophilicity Indices of Some Formyl- and Acetylpyridine-3-Thiosemicarbazone Derivatives and Various Computed Descriptors
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Onisor, C.
(EN)
Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείας
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Onisor, C.
(EN)
Retention indices for formyl- and acetylpyridine-3-thiosemicarbazone derivatives were determined by RP-HPTGC experiments and were performed with methanol-water mixtures in different volume proportions as mobile phase on two stationary phases of different polarity: RP-18F(254s) and RP-18WF(254s)plates. The correlation coefficients obtained on the RP-18W stationary phase are somewhat higher than hose obtained on the RP-18 plates and it can be concluded that the methanol concentration in the mobile phase have a larger influence on the interactions of the compounds with the RP-18 stationary phase than with the RP-18W stationary phase. In order to describe the relationship between the chromatographic retention indices of investigated compounds (RMo, b, phi(o) and scores corresponding to the first principal component) and the computed physico-chemical and topological descriptors, a multivariate regression analysis was performed. Excellent structure-retention index models show the suitability of these descriptors in the structure-retention index correlation. In all cases, the path/walk 5 Randic shape index, the highest occupied and the lowest unoccupied molecular orbital play a dominant role in determining retention indices on both stationary phases with different polarities, and RP-18W phase denotes the contribution of the specific polarizability.
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