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 center dot center dot center dot 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) angstrom, b = 9.853( 3) angstrom, c = 12.248( 3) angstrom, alpha = 101.793( 19)degrees, beta = 94.941(17)degrees, gamma = 104.36( 2)degrees, Z = 2, D-x = 1.308 g/cm(3), mu (Mo-K-alpha) = 0.092 mm(-1). The structure was solved by direct methods and refined to a final R = 0.0371 for 2183 reflections with I > 2 sigma ( I). The crystal structure is stabilized by N+ - H center dot center dot center dot O- type intra-molecular hydrogen bonds and N+ - H center dot center dot center dot 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 degrees to + 180 degrees in every 10 degrees separately and then molecular energy profile is calculated and construed. In addition, charge-population analysis of the crystallographically observed structure confirms its zwitterionic form.