Orientation of methanol enclathrated in the β-hydroquinone lattice: an X-ray crystallographic study

Abstract

The crystal structure of a β-hydroquinone–methanol clathrate, 3C₆H₄(OH)₂·xCH₃OH (x= 0.887), has been determined. The encaged CH₃OH molecule has three preferred orientations related by three-fold rotation about the c axis. In each orientation, the C–O bond is tilted by 35° from c to facilitate interaction of the hydroxy-group with three phenolic oxygen atoms of a neighbouring [OH]₆ring. Crystals are rhombohedral, space group R3, with Z= 3 in a hexagonal unit cell of dimensions a= 16.621 (2), c= 5.562(1)Å. Refinement of 632 observed data yielded R 0.043.