Diaqua-(5-carb-oxy-benzene-1,3-dicarboxyl-ato-κO(1))[8-ethyl-5-oxo-2-(piperazin-4-ium-1-yl)-5,8-dihydro-pyrido[2,3-d]pyrimidine-6-carboxyl-ato-κ(2)O(5),O(6)]zinc monohydrate.

In the title compound, [Zn(C(14)H(17)N(5)O(3))(C(9)H(4)O(6))(H(2)O)(2)]·H(2)O, the complex mol-ecule exists in a zwitterionic form. The Zn(II) ion exhibits a distorted tetra-gonal-pyramidal geometry, being coordinated by two O atoms from the zwitterionic 8-ethyl-5-oxo-2-(piperazin-4-ium-1-yl)-5,8-dihydro-pyrido[2,3-d]pyrimidine-6-carboxyl-ate (L) ligand, one O atom from the 5-carb-oxy-benzene-1,3-dicarboxyl-ate dianion, [Hbtc](2-), and two O atoms from two aqua ligands. In the crystal, N-H⋯O and O-H⋯O hydrogen bonds link the components into a three-dimensional structure. The crystal packing exhibits π-π inter-actions between the aromatic rings, with centroid-centroid distances in the range 3.466 (3)-3.667 (3) Å.

Bis[1-cyclo-propyl-6-fluoro-4-oxo-7-(1-piperazin-4-ium-1-yl)-1,4-dihydro-quinoline-3-carboxyl-ate-κO,O]bis-(nitrato-κO)copper(II).

In the title complex, [Cu(NO(3))(2)(C(17)H(18)FN(3)O(3))(2)], the Cu(II) ion is located on an inversion center. It exhibits a distorted octa-hedral geometry, being coordinated by six O atoms, four from two ciprofloxacin ligand mol-ecules (L), which act as bidentate ligands, and two from two nitrate anions. In the ligand, the piperazine ring has a chair conformation and the quinoline system is essentially planar [maximum deviation = 0.097 (2) Å]. One of the nitrate O atoms is disordered over two positions [occupancy ratio = 0.51 (6):0.49 (6)]. There is a C-H⋯F inter-action in the complex. In the crystal, mol-ecules are linked via N-H⋯O hydrogen bonds generating a two-dimensional network lying parallel to (111). The presence of C-H⋯O inter-actions leads to the formation of a three-dimensional structure. The title complex was prepared by hydro-thermal synthesis, and the hexa-hydrate form of this complex, synthesized by conventional methods, has been reported previously [Hernandez-Gil et al. (2009 ▶). Polyhedron, 28, 138-144].

4-(1-Cyclo-propyl-6-fluoro-4-oxo-1,4-dihydro-quinolin-7-yl)piperazin-1-ium 2,4,5-tricarb-oxy-benzene-1-carboxyl-ate monohydrate.

In the crystal of title compound, C(16)H(19)FN(3)O(+)·C(10)H(5)O(8) (-)·H(2)O, the water mol-ecule and the ions are connected by inter-molecular N-H⋯O and O-H⋯O hydrogen bonds and π-π stacking [centroid-centroid separation = 3.602 (1) Å] between the benzene ring and the pyridine ring, generating a three-dimensional supra-molecular structure.

Bis[8-ethyl-5-oxo-2-(piperazin-4-ium-1-yl)-5,8-dihydro-pyrido[2,3-d]pyrimidine-6-carb-oxy-lic acid] 2,5-dicarb-oxy-benzene-1,4-di-carboxyl-ate octa-hydrate.

The asymmetric unit of the title compound, 2C(14)H(18)N(5)O(3) (+)·C(10)H(5)O(8) (2-)·8H(2)O, contains one [H(2)ppa](+)cation, one half of an [H(2)btec](2-) anion (H(4)btec = 1,2,4,5-benzene-tetra-carb-oxy-lic acid and Hppa = 8-ethyl-5-oxo-2-piperazin-1-yl-5,8-dihydro-pyrido[2,3-d]pyrimidine-6-carb-oxy-lic acid) that is completed by inversion symmetry and four water mol-ecules. In the crystal, the mol-ecules are connected by inter-molecular hydrogen-bonding inter-actions and π-π stacking between the benzene rings of the [H(2)btec](2-) anion and the pyrimidine rings of the [H(2)ppa](+) cation [centroid-centroid distance = 3.597 (3) Å], generating a three-dimensional supra-molecular structure.