IUCr journals


Acta Cryst. (2008). E64, o841 [doi:10.1107/S1600536808009677]

[Unit-cell diagram]Unit-cell diagram showing the O–H...O=C hydrogen-bonded chain along b. Adjacent layers along c are chirally pure with alternating chirality. This is indicated by light- and dark-green shading of C atoms.
The racemic molecules of this tricyclic compound undergo a considerable degree of enantiomer separation during crystallization. They assemble by means of O–H…O=C hydrogen-bonded interactions into parallel enantiomerically pure chains oriented along the b direction, and then further aggregation of these chains results in formation of homochiral layers in the ab plane. This type of crystallization outcome, midway between intimate mixing of the enantiomers and conglomerate formation, is a poorly understood phenomenon.

I.Y.H. Chan, R. Bishop, D.C. Craig, M.L. Scudder and W. Yue