Structures of 1-(3,4-Dihydroxyphenyl)-2-(3,4-dimethoxyphenyl)ethanone and Its Hydrate Complex

The title compounds, C16H16O5 (I) and C16H16O5 center dot H2O (II), were structurally characterized by single-crystal X-ray diffraction. Compound I crystallizes in monoclinic space group P2(1)/c with a = 10.5574(10), b = 8.3576(9); c = 16.5528(16) angstrom, beta = 91.762(3)degrees, Z = 4, R = 0.0524 and wR = 0.1084. The molecules are jointed into a chain by intermolecular O-H center dot center dot center dot O and C-H center dot center dot center dot O hydrogen bonds, which form layers parallel to (001). The chains run along the [110] and [1 (1) over bar0] directions alternatively layer by layer, and are assembled into a network by intermolecular O-H center dot center dot center dot O (carboxyl) hydrogen bonds. On the other hand, the hydrate complex (II) crystallizes in the triclinic space group P (1) over bar with a = 5.1451(2), b = 10.4583(4), c = 14.8267(5) angstrom, alpha = 70.900(2), beta = 82.478(2), gamma = 81.359(2)degrees, Z = 2, R = 0.0393 and wR = 0.0983. The molecules are linked into infinite two-dimensional ribbons by O-H center dot center dot center dot O (carbonyl) and solvent-bridged O-H center dot center dot center dot O hydrogen bonds.