Crystal structure of cloxacillin sodium monohydrate, C19H17ClN3O5SNa(H2O)

Abstract

The crystal structure of cloxacillin sodium monohydrate has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional techniques. Cloxacillin sodium monohydrate crystallizes in space group P212121 (#19) with a = 7.989 36(12), b = 10.918 09(10), c = 25.559 3(6) Å, V = 2229.50(5) Å3, and Z = 4. The crystal structure is characterized by corner-sharing chains of irregular NaO5 polyhedra along the a-axis. The carboxylate group chelates to the Na and bridges two Na cations. The coordination sphere is completed by the water molecule and a carbonyl group. The Na–O bonds are mostly ionic but have some covalent character. The bond valence sum of the Na is 1.14. The water molecule acts as a donor to the carboxylate group and a carbonyl oxygen. It is an acceptor in C–H⋯O hydrogen bonds from a methyl group and a ring carbon. The crystal structure of cloxacillin sodium monohydrate is very similar to that of the fluorinated derivative (CSD Refcode BEBCAM), reflecting the similarity of the lattice parameters. The powder pattern has been submitted to ICDD for inclusion in the Powder Diffraction File™.