Crystallographic and conformational analyses of zwitterionic form of (E)-2-methoxy-6-[(2-morpholinoethylimino)methyl]phenolate

Abstract

The single crystal X-ray diffraction analysis of the title compound, C14H20N2O3, reveals that the structure is adapted to its zwitterionic form and $$R_2^2 (12)$$ centrosymmetric dimers are formed by N+–H···O− type ionic weak hydrogen bonds in the crystal structure. The title compound crystallizes in the triclinic space group P−1 with a = 5.9255(13) A, b = 9.853(3) A, c = 12.248(3) A, α = 101.793(19)°, β = 94.941(17)°, γ = 104.36(2)°, Z = 2, Dx = 1.308 g/cm3, μ (Mo-Kα) = 0.092 mm−1. The structure was solved by direct methods and refined to a final R = 0.0371 for 2183 reflections with I > 2σ (I). The crystal structure is stabilized by N+–H···O− type intra-molecular hydrogen bonds and N+–H···O− type packing interactions referred to as weak hydrogen bonds. To elucidate conformational flexibility of the title molecule, the selected torsion angle is varied from −180° to +180° in every 10° separately and then molecular energy profile is calculated and construed. In addition, charge-population analysis of the crystallographically observed structure confirms its zwitterionic form.