Anthracene based bulky diol hosts.: Crystal structures of a free host and of inclusion compounds with dipolar guests

X-ray crystal structures are reported of a free host compound 1, comprising two diphenylmethanol terminal groups attached to a central 9,10-ethynyl substituted anthracene unit, and of three inclusion compounds of a fluoren-9-ol substituted analogous host 2 with acetone, dimethyl sulphoxide (DMSO) and dimethylformamide (DMF) as guest, respectively. Despite the presence of two hydroxyl groups in 1, there is no O-H...O hydrogen bond between the molecules in the guest free crystal-only weaker C-H...O interactions and van der Waals' type connections. In the inclusion compounds of 2, H-bonded 1:2 host-guest associates are formed, where each of the host hydroxyl groups binds to a guest oxygen atom. The orientations of the host-guest connections in these complexes vary, being E for acetone and Z for both DMSO and DMF guests, relative to the host anthracene unit. The DMSO and DMF inclusion compounds of 2 proved to be isostructural.