Crystal structure of 3,3′-dimethoxybenzydine (2-hydroxybenzal)diimine

Molecular and crystal structure of 3,3′-dimethoxybenzydine(2- hydroxybenzal)diimine, C ₂₈ H ₂₄ N ₂ O ₄ , have been determined by single crystal X-ray diffraction study. The title compound is monoclinic, with a = 18.045(2) Å, b = 11.725(4) Å, c = 12.436(6) Å, β = 120.03(3)°, Z = 4, D _x = 1.32 g/cm ³ , μ(MoK _α ) = 0.089 mm ^-1 , and space group is C2/c. The structure was solved by direct methods and refined to a final R = 0.056 for 2325 reflections with I > 2σ(I). There is half independent molecule in the asymmetric unit. The molecule has a twofold symmetry on the mid point of the C4-C4 ⁱ bond. The N1=C8 imine bond length of 1.284(3) Å is typical of a double bond. The molecule of the title compound is not planar. There is a strong intramolecular hydrogen bond between hydroxy oxygen atom and imine nitrogen atom. The crystal structure is stabilized by a weak intermolecular hydrogen bond of the C-H ⋯ O type forming three-dimensional cage.