Hydrogen bonding and C-H...O interactions in 2,2'-dihydroxy-5,5'-dimethoxybiphenyl-3,3'-dicarbaldehyde

The title dialdehyde, C16H14O6, crystallized in the centrosymmetric space group P1 with one molecule in the asymmetric unit. In this structure, one intermolecular and two intramolecular hydrogen bonds occur; the OD...OA distances are 3.030(2), 2.626(2) and 2.662(2) A. In addition, ten significant C-H...O interactions have C...O distances ranging from 3.342(2) to 3.741(3) A and C-H...O angles ranging from 117 to 167 degrees. The 11 intermolecular interactions link a molecule directly to eight neighbors and form a richly three-dimensional network. The dihedral angle between the best-fit planes of the benzene rings within a molecule (biphenyl twist angle) is 79.00(8) degrees. The dihedral angles between the carboxaldehyde-group planes and the best-fit planes of the rings to which they are attached are 4.7(10) and 2.6(10) degrees.