Hydrogen bonding. Part 18. Gas–liquid chromatographic measurements for the design and selection of some hydrogen bond acidic phases suitable for use as coatings on piezoelectric sorption detectors

Abstract

A number of involatile liquids based on 4,4′-isopropylidenediphenol (bisphenol-A) or other bisphenols have been prepared as candidate coatings for piezoelectric sorption detectors. The liquids have been used as GLC stationary phases, and gas–liquid partition coefficients of a series of solutes have been obtained for these phases. Application of the linear solvation energy equation below has revealed that two particular liquids (8 and 9) possess very large hydrogen bond acidities coupled to rather small hydrogen bond basicities, and hence might be suitable as coatings with selectivity towards solutes that are hydrogen bond bases. One other compound (10) is not suitable as a coating because it is a solid at room temperature, but it has very considerable hydrogen bond acidity, and may be suitable as a novel GLC stationary phase. In the linear solution log K=c+rR₂+sπ₂^H+aα₂^H+bβ₂^H+l log L¹⁶ energy equation above, K is the gas–liquid partition coefficient for a series of solutes on a given phase, and the explanatory variables R₂, π₂^H, α₂^H, β₂^H and log log L¹⁶ are solute parameters that we have described before. A term by term analysis of the equation can be used to evaluate quantitatively how specific solute–solvent interactions influence the magnitude of the various log K values.