Crystal Structure and Conformational Analysis of 4-[(p-N,N-Dimethylamino) benzylidene]-2-(3,5-dinitrophenyl)oxazole-5-one

An azlactone derivative, 4-[(p-N,N-dimethylamino)benzylidene]-2-(3,5-dinitrophenyl)oxazol-5-one (DNPO), C18H14N4O6, has been synthesized, and its crystal structure has been investigated by single crystal X-ray analysis and ab initio method. DNPO is monoclinic, with a=9.3628(4), b=13.5148(9), c=13.7701(6), =92.921(4), Z=4, Dx=1.46g/cm3, (MoK)=0.112mm-1, and space group P 121/c1. The whole molecule is almost planar. The crystal structure is stabilized by C-HN type intramolecular, C-HO type intermolecular interactions. To determine the flexibility of DNPO, the selected torsion angle is varied from-180 to 180 in steps of 10, and the molecular energy profile is calculated and analyzed.