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

Abstract

Molecular and crystal structure of 3,3'-dimethoxybenzydine(2-hydroxybenzal)diimine, C₂₈H₂₄N₂O₄, 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/cm³, 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$---$C4ⁱ 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.