(4R,5R)-bis(diphenylhydroxymethyl)-2-spiro-1’-cyclohexane-1,3-dioxolane: an investigation of its host ability and selectivity behaviour in crystallization experiments from four heterocyclic guest solvents

The present investigation demonstrated that (4R,5R)-bis(diphenylhydroxymethyl)-2-spiro-1’-cyclohexane-1,3-dioxolane (TADDOL6) possessed the ability to form 1:1 host: guest inclusion compounds with dioxane, piperidine, morpholine and pyridine (DIO, PIP, MOR, PYR) when it was crystallized from these solvents. When mixed guests were employed as the crystallization solvent, TADDOL6 showed an overwhelming preference for PYR, and the host selectivity was noted to be in the order PYR > PIP > MOR > DIO. From SCXRD analyses, it was observed that each of the four organic guest solvents was held in the crystal of the complex by means of classical hydrogen bonding interactions with the host species, with PIP experiencing, statistically, the shorter of these. Hirshfeld surfaces were also considered and demonstrated that the preferred guest species, PYR, experienced the broader range of short contact types. Finally, thermal analyses also explained the host selectivity order: PYR, which was most favoured by TADDOL6, formed a complex with the greatest thermal stability of the four, while the complex with DIO, which was least preferred by TADDOL6, possessed the lowest stability.