Conformational and crystallographic investigations of some azlactone derivatives

Molecular and crystal structure of `4-[(p-N,N-dimethylamino)benzylidene]-2-phenyl oxazol-5-one? and `2-(3,5-dinitrophenyl)-4-(N,N-dimethylamino benzylidene)-5- oxazolone? have been determined by single crystal X-ray diffraction study. The first compound is crystallized in the monoclinic system. The structure was solved by direct methods thods and refined to a final R=0.047 for 3166 reflections with I > 2? (I ) . The crystal structure of C18H16N2O2 is stabilized by C?H···O and C?H···N type intra-molecular, C?H···O type inter-molecular interactions. The second compound is crystallized in the monoclinic system. The structure was solved by direct methods and refined to a final R=0.042 for 3404 reflections with I > 2? (I ) . The crystal structure is stabilized by C?H···N type intra-molecular, C?H···O type intermolecular interactions. Both of the compounds are almost planar. In addition; to enlighten the flexibility of the compounds, the selected torsion angles are varied from -180o to 180o in every 10o separately and molecular energy profile is calculated and analyzed. It is concluded that where the profile has minimums, there are intra-molecular weak interactions, such as H-bonding.