Tetrakis[bis(pyridin-2-yl)amine-κN 2](nitrato-κO)silver(I)

In the title complex, [Ag(NO3)(C10H9N3)4], the nitrate ligand is found to be disordered over two sets of positions, with occupancy factors of 0.473 (5) and 0.527 (5). The AgI ion is located in a square-pyramidal coordination environment formed by four N atoms from four bis(pyridin-2-yl)amine ligands and one O atom from a nitrate ligand. Weak interactions between the AgI ions and the nitrate anions acting in a monodentate mode [Ag⋯O = 2.791 (13) and 2.816 (9) Å for the major component of the nitrate ligand, and 2.865 (8) and 2.837 (8) Å for the minor component] link the complex molecules into a chain along [001]. N—H⋯O hydrogen bonds are observed.

In the title complex, [Ag(NO 3 )(C 10 H 9 N 3 ) 4 ], the nitrate ligand is found to be disordered over two sets of positions, with occupancy factors of 0.473 (5) and 0.527 (5). The Ag I ion is located in a square-pyramidal coordination environment formed by four N atoms from four bis(pyridin-2-yl)amine ligands and one O atom from a nitrate ligand. Weak interactions between the Ag I ions and the nitrate anions acting in a monodentate mode [AgÁ Á ÁO = 2.791 (13) and 2.816 (9) Å for the major component of the nitrate ligand, and 2.865 (8) and 2.837 (8) Å for the minor component] link the complex molecules into a chain along [001]. N-HÁ Á ÁO hydrogen bonds are observed.
The preparation of dipam was reported by Wibaut & Dingemanse (1923) and since that time it was widely used for constructing complexes with transition metals. Two crystalline modifications of the compound C 10 H 9 N 3 are known, one with melting point at 84°, while a second melts at 94°C. In this paper we report the synthesis and characterization of the

Refinement
The nitrate anion was disordered over two sets of sites with occupancies 0.527 (5) and 0.473 (5). The N-O and O-O distances as well as the anisotropic displacement parameters of the N and O atoms within these disordered anions were restrained to be similar. Furthermore, the geometry of the nitrate anion was restrained to be planar. One of the pyridyl N atoms (N7) was restrained so that its U ij components approximate to isotropic behavior. H atoms were positioned geometrically and refined as riding atoms, with C-H = 0.95 and N-H = 0.88 Å and with U iso (H) = 1.2U eq (C, N). The highest residual peak is located 0.30 Å from atom O3A and the deepest hole is located 0.12 Å from atom O2A.

Figure 1
The molecular structure of the title complex. Displacement ellipsoids are drawn at the 50% probability level. The minor disordered fraction has been omitted for clarity.  The unit cell of the title complex. H atoms and minor disordered atoms has been omitted for clarity.

Tetrakis[bis(pyridin-2-yl)amine-κN 2 ](nitrato-κO)silver(I)
where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 1.05 e Å −3 Δρ min = −2.19 e Å −3 Special details Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq Occ.