No abstract

Crystalline inclusion compounds of diol hosts 1 and 2 typical of a basic 2,2″-[1,1′:4′,4″]-terphenyl moiety with two attached 9-fluorenol or tertbutyl-substituted 9-fluorenol units and a variety of aprotic guest molecules have been prepared and studied with reference to their crystal structures. Common and differing structural features among one another and including previously described host−guest complexes of 1 and 2 with protic instead of aprotic guest species are distinguished, indicating potential uses in promising supramolecular inclusion formation and underscoring solvent inclusion.

In the crystal structure of 2,2′′-bis­(2,7-di­chloro-9-hy­droxy-9-fluoren­yl)-1,1′:4′,1′′-terphenyl as the tris­(tri­ethyl­amine) solvate, the diol host mol­ecule possesses a ‘folded’ mol­ecular conformation with inversion symmetry. Two of the three solvent mol­ecules form O—H⋯N hydrogen bonds and the third one forms C—H⋯N hydrogen bonds with the host compound.

Imitative of a supramolecular synthon moiety D comprising two 3,5-bis(hydroxymethyl) substituted benzoic acid moieties (2), the covalently linked surrogate molecule 1 has been designated and synthesized. Crystal structures have been compared including also substituted and molecularly elongated derivatives of 2. They show largely common structural features in planar geometry of the building units and layer formation in the crystal packing, while the hydrogen bonded patterns within the layers differ according to the structural molecular changes. Moreover, synthon robustness of the dimer carboxylic acid motif has been confirmed.