Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals, Vol.356, 289-297, 2001
Role of the (O-H)(6) synthon in the construction of organic inclusion compounds
The racemic diol 5 crystallises from ethanol in the orthorhombic space group Cmca (a 19.05, b 14.93, c 10.12 Angstrom) as the cocrystalline solid 5 .C2H5OH. In contrast, the racemic diol 6 crystallises from benzene in the cubic space group Ia3 (a 19.85 Angstrom) as a clathrate compound. The principal supramolecular synthon involved in both cases is a cyclic hexamer of hydrogen bonded hydroxy groups, (O-H)(6). While the former cycle is almost planar, rather uncommonly the latter is cyclohexane-like in geometry. A major function of the (O-H)(6) cycle is to allow efficient packing between opposite enantiomers within the crystal lattice.
Keywords:hydrogen bonding;inclusion compounds;host-guest compounds;supramolecular synthons;hydroxy groups;enantiomeric packing