TRIARYLMETHANOL HOSTS AND ANALOGS .9. CRYSTALLINE ALCOHOLIC INCLUSIONS OF SINGLY-BRIDGED TRIARYLMETHANOL HOSTS - SYNTHESIS, X-RAY CRYSTAL-STRUCTURES AND BINDING MODES OF 5 INCLUSION-COMPOUNDS

Five alcoholic inclusion compounds of singly-bridged triarylmethanol hosts have been synthesized and investigated by X-ray diffraction. In four cases recognition of the alcoholic guest by the host is characterized by a coupled system of hydrogen bonds in the form of closed loops. The centrosymmetric hydrogen-bonded rings, with full hydrogen bond saturation, are created by four -OH groups belonging to two host and two guest molecules. in the fifth complex, however, 'anomalous' hydrogen-bonded 2:1 host:guest associates are formed without full saturation of hydrogen bonds. In the crystals the hydrogen-bonded units are held together mostly by ordinary Van der Waals' forces, occasionally supported by electrostatic C-H ... O interactions.