Buy article online - an online subscription or single-article purchase is required to access this article.
organic compounds
The title compound, C8H10O2, was prepared from diacetyl by a high temperature and pressure reaction. Pseudosymmetry in the structure results in diffraction symmetry enhancement for half the reflections and the possibilility of twinning and stacking faults. The structure consists of two independent but pseudosymmetrically related P21/c substructures, each having centrosymmetric molecules on centres of inversion which are strongly hydrogen bonded to symmetry-related molecules to form layers perpendicular to c*. The structure may be described as an occupancy modulation, ordering a disordered parent structure in Pnma symmetry to form, upon change of axes, the P21/c structure reported. The hydroxyl H atoms have two site options corresponding to alternative hydrogen-bonding patterns and the methyl H atoms in one substructure are rotationally disordered.