Clathrate design for dioxane inclusion involving singly bridged triarylmethanol hosts. Synthesis, X-ray crystal structures and thermal stabilities of five inclusion compounds

Abstract

A series of singly bridged triarylmethanols, with different substituents and modified bridging units, form crystalline inclusion compounds with dioxane. X-ray diffraction studies revealed hydrogen bonds between host and guest in all these structures, and in one case also a host-to-host hydrogen bond. Most crystals contain either 1 : 1 or 2 : 1 hydrogen-bonded host–dioxane complexes, dependent on the structural parameters of the host molecule. With both host–guest and host–host hydrogen bonds present, 4 : 1, host–dioxane units are formed. Some structures accommodate additional dioxane guests which are held by van der Waals forces. The stabilities of the different dioxane clathrates were studied by thermal analysis.