[2,9-Bis(3,5-dimethyl-1H-pyrazol-1-yl-κN 2)-1,10-phenanthroline-κ2 N,N′](methanol-κO)(nitrito-κ2 O,O′)cadmium(II) perchlorate

In the title complex, [Cd(NO2)(C22H20N6)(CH3OH)]ClO4, the CdII ion is in a distorted pentagonal–bipyramidal CdN4O3 coordination geometry. The dihedral angles formed between the mean planes of the pyrazole rings and the phenanthroline ring system are 4.37 (19) and 5.84 (21)°. In the crystal, the anions and cations are connected by intermolecular O—H⋯O hydrogen bonding, while pairs of weak intermolecular C—H⋯O hydrogen bonds connect the cations into centrosymmetric dimers. In addition, there is a π–π stacking interaction involving two symmetry-related benzene rings, with a centroid–centroid distance of 3.437 (3) Å.

In the title complex, [Cd(NO 2 )(C 22 H 20 N 6 )(CH 3 OH)]ClO 4 , the Cd II ion is in a distorted pentagonal-bipyramidal CdN 4 O 3 coordination geometry. The dihedral angles formed between the mean planes of the pyrazole rings and the phenanthroline ring system are 4.37 (19) and 5.84 (21) . In the crystal, the anions and cations are connected by intermolecular O-HÁ Á ÁO hydrogen bonding, while pairs of weak intermolecular C-HÁ Á ÁO hydrogen bonds connect the cations into centrosymmetric dimers. In addition, there is astacking interaction involving two symmetry-related benzene rings, with a centroid-centroid distance of 3.437 (3) Å .

Related literature
For a related structure, see: Zheng & Chi (2011).
The molecular structure of the title compound is shown in Fig. 1. The Cd II ion is in a distorted pentagonal bipyramidal coordination geometry, which may be attributed to the chelation modes of the 2,9-bis(3,5-Dimethyl-1H-pyrazol-1-yl)-1,10phenanthroline ligand and nitrite anion ligand. The dihedral angles between the planes that consist of the non-hydrogen atoms of the 1,10-phenanthroline ring system and the pyrazole rings are 4.37 (19)° (involving the pyrazole ring containing atoms N1 and N2) and 5.84 (21)° (involving the pyrazole ring containing atoms N5 and N6), respectively. In the crystal, the anion and cation are connected by an intermolecular O-H···O hydrogen bond, while pairs of weak intermolecular C-H···O hydrogen bonds connect cations into centrosymmetric dimers. In addition, there is a π-π stacking interaction involving symmetry-related complexes, the relevant distance being Cg1···Cg1 i 3.437 (3) Å and Cg1···Cg1 i perp = 3.378 Å (symmetry code: (i) 2-x, 1-y, 2-z; Cg1 is the centroid of the C9-C14 benzene ring; Cg1···Cg1 i perp is the perpendicular distance from Cg1 ring to Cg1 i ring).

Experimental
A 5 ml H 2 O solution of NaNO 2 (0.0310 g, 0.449 mmol) was added into 8 ml methanol solution of Cd(ClO 4 ).6H 2 O (0.0939 g,0.224 mmol) and the solution was mixed with a 10 ml dichloromethane solution of 2,9-bis(3,5-Dimethyl-1H-pyrazol-1yl)-1,10-phenanthroline (0.0353 g, 0.112 mmol), and stirred for a few minutes. Colorless single crystals were obtained after the filtrate had been allowed to stand at room temperature for about two week.

Refinement
The position of the H atom of the hydroxyl group was located in a difference Fourier map and other H atoms were placed in calculated positions. All H atoms were refined as riding with O-H = 0.87 Å, U iso = 1.5U eq (O) for hydroxyl H, C-H = 0.96 Å, U iso = 1.5U eq (C) for methyl H, and C-H = 0.93 Å, U iso = 1.2U eq (C) for other H atoms.
supplementary materials sup-2 Figures Fig. 1. The asymmetric unit of the title compound with displacement ellipsoids shown at the 30% probability level.