Enclathration of Picoline Isomers by (rac)-TADDOLs: Structures, Selectivity, and Thermal Analysis

In this investigation, we studied the preferences of three α,α,α′,α′-tetraphenyl-l,3-dioxolane-4,5-dimethanol (TADDOL)-derived host compounds toward the isomers of methyl-pyridines (picolines). Ten novel inclusion compounds were synthesized, and their structural and thermal properties were further characterized. Binary competition experiments were performed, and all three hosts discriminate between the picoline isomer guests. Interestingly, all three hosts display different preferences toward the isomers, and these results were rationalized by their resulting crystal structures and packing analysis and correlated to their differential scanning calorimetry (DSC) results. DSC results showed a correlation between the thermal stability of an inclusion compound and the preference of the host toward a given isomer.