On the Solute-Stationary Phase Interaction in Gas-Liquid Chromatorgaphy. Evaluation on the Relative Retention Values for Mono- and Polyalkyo-Substituted Benzene Derivatives

The values of log γ for monosubstituted benzene derivatives can be expressed after regression analyses by a linear combination of the quantitative structure-activity relationship (QSAR) descriptors σs°, μ2/α, and σ±π. The inclusion of aniline series derivatives demands and additional descriptor pKa, ascribed to the CH/N interaction between the stationary liquid and the nitrogen lone pair. Furthermore, for all cases of polyalkylvenzene derivatives, the descriptor σs° is effective, and the number of vicinal type CH3-pairs represented at first by the descriptor ortho numver No can be transformed to the corrected σ+π, representing the CH/π type charge-transfer interaction between the substrate and the stationary liquid.