Structure Reports Online

Volume 65, Part 6 (June 2009)

organic compounds

Acta Cryst. (2009). E65, o1241 [ doi:10.1107/S1600536809016547 ]

2,8-Dimethyltricyclo[5.3.1.1^3,9]dodecane-syn-2,syn-8-diol-propanoic acid (1/1)

Y. Mizobe, R. Bishop, D. C. Craig and M. L. Scudder

Abstract: The racemic title compound, C₁₄H₂₄O₂·C₃H₆O₂, crystallizes in the monoclinic space group P2₁/c as a 1:1 diol/carboxylic acid cocrystal, A-B. The lattice incorporates infinite chains of the alcohol-carboxylic acid-alcohol supramolecular synthon, (O-HO=C(R)-O-HO-H), in which the hydrogen-bonded molecules (A-B-A)_n surround a pseudo-threefold screw axis. The carboxylic acid group functions like an extended alcohol hydroxy group. Each diol, A, takes part in two such threefold screw arrangements, leading to a hydrogen-bonded layer structure, with adjacent layers containing diol molecules of opposite handedness. The central C atom of the propano bridge is disordered over two sites of occupancies 0.75 (1) and 0.25 (1). The methyl group of the propanoic acid molecule is disordered over two sites of occupancies 0.68 (1) and 0.32 (1).