Molecular structure of two copper complexes with pharmaceuticals norfloxacin and tinidazole, when powder X-ray diffraction assists multi-domains single-crystal X-ray diffraction. Addendum.

The crystal structures of bis[1-ethyl-6-fluoro-4-oxo-7-(piperazin-1-ium-4-yl)-1,4-dihydroquinoline-3-carboxylato]copper (II) sulfate heptahydrate, [Cu(C16H18F-N3O3)(2)]SO4 center dot 7H(2)O or [Cu(nor)(2)]SO4 center dot 7H(2)O (nor is norfloxacin), and bis{1-[2-(ethylsulfonyl)ethyl]-2-methyl-5-nitroimideldinitratocopper (II), [Cu(NO3)(2)(C8H13N3O4S)(2)] or [Cu(NO3)(2)(tnz)(2)] (tnz is tinidazole), were solved by X-ray diffraction. Both complexes crystallize in the space group P2(1)/c, with Z = 4 (for nor) and Z = 2 (for ntz) molecules per unit cell. In [Cu(nor)(2)]SO4 center dot 7H(2)O, the Cu-II ion is at the centre of a square-planar environment, trans coordinated to two independent norfloxacin molecules in the zwitterionic form acting as bidentate ligands through one of the carboxyl (cbx) and the carbonyl (cb) O atoms. The solid is further stabilized by an extensive network of N-H center dot center dot center dot O(sulfate), N-H center dot center dot center dot O(cbx), N-H center dot center dot center dot OW, OW-H center dot center dot center dot-O(sulfate) and OW-H center dot center dot center dot OW hydrogen bonds. The [Cu(NO3)(2)(tnz)(2)] complex is centrosymmetric, with the Cu-II ion in a square planar environment, coordinated to a tinidazole molecule acting as a monodentate ligand through its imidazole N atom and to one nitrate O atom. The vibrational FT-IR absorption spectra and thermal behaviour of the complexes were also studied and are briefly discussed based on the crystal structures.