Bis(N′-benzoylpyridine-4-carbohydrazide)(1,10-phenanthroline)copper(II) dinitrate

In the title complex, [Cu(C13H11N3O2)2(C12H8N2)](NO3)2, the CuII atom (site symmetry 2) is coordinated by four N atoms from one 1,10-phenanthroline and two hydrazine ligands, respectively. The hydrazine ligands coordinate to the CuIIatom by a pyridine N atom. These four atoms form a slightly distorted square-planar N4 donor set. In the packing, two additional Cu⋯O interactions occur [Cu⋯O = 2.462 (2) Å], resulting in a typical Jahn–Teller-distorted octahedral environment around the Cu atom. N—H⋯O hydrogen bonds result in a three-dimensional network. The O atoms of the anion are disordered over two positions in a 0.68 (2):0.32 (2) ratio.

In the title complex, [Cu(C 13 H 11 N 3 O 2 ) 2 (C 12 H 8 N 2 )](NO 3 ) 2 , the Cu II atom (site symmetry 2) is coordinated by four N atoms from one 1,10-phenanthroline and two hydrazine ligands, respectively. The hydrazine ligands coordinate to the Cu II atom by a pyridine N atom. These four atoms form a slightly distorted square-planar N 4 donor set. In the packing, two additional CuÁ Á ÁO interactions occur [CuÁ Á ÁO = 2.462 (2) Å ], resulting in a typical Jahn-Teller-distorted octahedral environment around the Cu atom. N-HÁ Á ÁO hydrogen bonds result in a three-dimensional network. The O atoms of the anion are disordered over two positions in a 0.68 (2):0.32 (2) ratio.
1. The Cu II atom lying on an inversion center is coordinated by two N atoms from one phen and two pyridine N atoms of two ligands with Cu-N mean distance of 2.013 (2) Å. Therefore, the local coordination geometry of copper center is square-planar with N4 donor set. The mean deviation from the best plane through these N atoms is 0.072 (2) Å. In addition, a weak interaction exists between every Cu II atom and two adjacent oxygen atoms (O2) (Cu-O2 = 2.462 (2) Å) of the ligands in the packing diagram (Fig. 2). So, four N atoms and two O atoms form an octahedral environment around the Cu II atom.
Four N atoms and the Cu II atom form the equatorial plane, the axial position is occupied by two O2 atoms. In the compound, oxygen atoms of nitrate exhibit disorder. Three oxygen atoms are split between two sites with occupancies of 50% (O3 to O5 and O3' to O5'). The crystal packing of (I) (Fig. 2) involves N-H···O hydrogen bonds (Table 1). The nitrate O3 and O3' atoms accept intermolecular hydrogen bonds from the N4 atom of hydrazine, while O4 accepts an intermolecular hydrogen bond from the N3 atom of hydrazine and O4' interacts with both N3 and N4. These interactions and the weak interactions of Cu II atoms and adjacent oxygen atoms result in a three-dimensional network of hydrogen bonds.

Experimental
The synthesis of the ligand has been reported by Bian et al. (2005). N'-Benzoylpyridine-4-hydrazide (0.5 mmol) and Cu(NO 3 ) 2 .3H 2 O (0.5 mmol) were added to the mixed solution of methanol (20 ml) and DMF (2.5 ml), meanwhile, phen (0.5 mmol) was added to the above solution. The mixture was heated and refluxed for 1.5 h, and then filtered. The filtrate was kept at room temperature for two weeks and blue crystals were obtained.

Refinement
The oxygen atoms of the nitrate group exhibit disorder. Two sets of oxygen atoms, O3 to O5 and O3' to O5', with site-occupation factors 0.5 were refined with restraints on distances and displacement parameters. H atoms on C atoms were positoned geometrically and refined using a riding model with C-H = 0.93 Å and U iso (H) = 1.2U eq (C). H atoms on N atoms were located in a difference Fourier map. Fig. 1. A view of the molecular structure of (I) with the atom-numbering scheme and 30% displacement ellipsoids (H atoms are omitted for clarity). Bis(N'-benzoylpyridine-4-carbohydrazide)(1,10-phenanthroline)copper(II) dinitrate Crystal data [Cu(C 13