Bis[4-amino-N-(pyrimidin-2-yl)benzenesulfonamidato]-κ2 N,N′;κN-aquabis(dimethylformamide-κO)cadmium(II) monohydrate

In the title compound, [Cd(C10H9N4O2S)2(C3H7NO)2(H2O)]·H2O, the CdII ion displays a grossly distorted octahedral (or irregular) mer-CdN3O3 coodination polyhdron arising from its coordination by one N,N′-bidentate sulfadiazinate anion, one monodentate sulfadiazinate anion, two O-bonded dimethylformamide molecules and one water molecule. A short Cd⋯N contact [2.890 (3) Å] to the monodentate sulfadiazinate ion also occurs. The dihedral angles between the planes of the aromatic rings of the anions are 86.81 (14) and 68.65 (14)°. The crystal structure features intermolecular N—H⋯O, O—H⋯O and O—H⋯N hydrogen bonds.

In the title compound, [Cd(C 10 H 9 N 4 O 2 S) 2 (C 3 H 7 NO) 2 (H 2 O)]Á-H 2 O, the Cd II ion displays a grossly distorted octahedral (or irregular) mer-CdN 3 O 3 coodination polyhdron arising from its coordination by one N,N 0 -bidentate sulfadiazinate anion, one monodentate sulfadiazinate anion, two O-bonded dimethylformamide molecules and one water molecule. A short CdÁ Á ÁN contact [2.890 (3) Å ] to the monodentate sulfadiazinate ion also occurs. The dihedral angles between the planes of the aromatic rings of the anions are 86.81 (14)
In addition there is one more solvated water molecule in the lattice. The Cd ion displays a hepta-coordinated complex but one of the pyrimido nitrogen atoms from the second sulfadiazinate anion has weak interaction with Cd(II) ion.
The hepta-coordinated cadmium complex is monocapped trigonal prismatic rather than the pentagonal bipyramidal structure as the angles around the cadmium centre are very much reduced from the ideal behavior since there exist different types of coordinated molecules.
The dihedral angle between the aromatic rings of the chelated anion of 88.82 (7)° is larger than value of 68.66 (9) (Table 2) and exists among sdz anions, coordinated and solvated water molecules (Hossain, 2011).

Experimental
The sodium salt of sulfadiazine (Nasdz, 5.446 g, 2 mmol) was dissolved in hot methanol (50 ml) and a methanol solution (10 ml) of (CH 3 COO) 2 Cd.2H 2 O (2.6647 g, 1 mmol) was added slowly with constant stirring on a hot plate. A white precipitate was formed and the mixture was stirred for a further 2 h. The precipitate was filtered off and dried over silica gel; it was then dissolved in dimethylformamide solution (50 ml), and the mixture stirred for 10 min., filtered and left for crystallisaton. A week later, white block-shaped crystals of (I) were filtered off and dried over silica gel.

Refinement
The H atoms were positioned geometrically and refined using a riding model [except that for terminal amino groups N14 and N24 and water molecules which were located from the difference map and fixed to 0.79 (2)-0.85 (3) Å], with C-H = 0.95-0.98 Å and with U iso (H) = 1.2 (1.5 for methyl groups) times U eq (C). Fig. 1. The molecular structure of (I), with 50% probability displacement ellipsoids for non-H atoms.