THE CRYSTAL AND MOLECULAR-STRUCTURE OF -CHLORO-2-HYDROXYPROPYL)-2-METHYL-5-NITROIMIDAZOLE (ORNIDAZOLE), C7H10CLN3O3

Ornidazole, C7H10ClN3O3, crystallizes in the triclinic, space group P (1) over bar, with a=13.6050, b=14.054(1), c=8.913(5) Angstrom, alpha= 71.59(2), beta=78.73(2), gamma=64.86(1)degrees, mu=3.26 cm(-1), Dc= 1. 494 g/cm(3), Dm=1.497 g/cm(3), F(000)=684, and z= 6. Intensities for 2 693 unique reflections were measured on a CAD4 diffractometer with gra phite-monochromated Mo-Ka radiation. The structure was solved by direc t method and refined by block-diagonal least squares to a final R of 0 .081 (Rw=0.047) for 1952 reflections with F0>3 sigma (F0). The asymmet ric unit contains three independent molecules of the tide compound. Th e bond lengths and bond angles are comparable with the values found in the other nitrosubstituted compounds. The nitro groups are rotated (6 .9 degrees, 6.6 degrees, 2.6 degrees for the three independent molecul e, respectively) about the C-N axes from the imidazole planes. The cry stal structures are linked by two intermolecular hydrogen bonds of O-H -N type and one intermolecular hydrogen bond of O-H-O type.