Tetrakis(azido-κN)(di-2-pyridylamine-κ2 N 2,N 2′)platinum(IV)

In the title complex, [Pt(N3)4(C10H9N3)], the PtIV ion is six-coordinated in a slightly distorted octahedral environment by the two pyridine N atoms of the chelating di-2-pyridylamine (dpa) ligand and four N atoms from four azide anions. The dpa ligand is not planar, the dihedral angle between the pyridine rings being 20.0 (3)°. The azide ligands are slightly bent [N—N—N = 173.5 (8)–175.1 (8)°]. In the crystal, the complex molecules are connected by N—H⋯N hydrogen bonds, forming a chain along the b axis. An intermolecular π–π interaction between the chains is also present, the ring centroid–centroid distance being 3.713 (4) Å.

In the title complex, [Pt(N 3 ) 4 (C 10 H 9 N 3 )], the Pt IV ion is sixcoordinated in a slightly distorted octahedral environment by the two pyridine N atoms of the chelating di-2-pyridylamine (dpa) ligand and four N atoms from four azide anions. The dpa ligand is not planar, the dihedral angle between the pyridine rings being 20.0 (3) . The azide ligands are slightly bent [N-N-N = 173.5 (8)-175.1 (8) ]. In the crystal, the complex molecules are connected by N-HÁ Á ÁN hydrogen bonds, forming a chain along the b axis. An intermolecularinteraction between the chains is also present, the ring centroid-centroid distance being 3.713 (4) Å .

Related literature
For the crystal structure of the related chlorido Pt IV complex [PtCl 4 (dpa)], see: Ha (2011).
In the title complex, [Pt(N 3 ) 4 (dpa)], the Pt IV ion is six-coordinated in a slightly distorted octahedral environment by the two pyridine N atoms of the chelating dpa ligand and four N atoms from four azide anions (Fig. 1). In the crystal structure, the dpa ligand is not planar. The dihedral angle between the least-squares planes of the pyridine rings is 20.0 (3)°. The Pt-N(dpa) and Pt-N(azide) bond lengths are nearly equivalent [Pt-N: 2.029 (7)-2.076 (6) Å] ( Table 1) Table 2). Along the b axis, successive chains stack in opposite directions. An intermolecular π-π interaction between the pyridine rings is also present, the ring centroid-centroid distance being 3.713 (4) Å.

Experimental
To a solution of Na 2 PtCl 6 .6H 2 O (0.1684 g, 0.300 mmol) in MeOH (30 ml) were added NaN 3 (0.2129 g, 3.275 mmol) and di-2-pyridylamine (0.1046 g, 0.611 mmol), and the mixture was refluxed for 5 h. The formed precipitate was separated by filtration and washed with H 2 O and MeOH, and dried at 50 °C, to give a yellow powder (0.0687 g). Crystals suitable for X-ray analysis were obtained by slow evaporation from an acetone solution.

Refinement
Carbon-bound H atoms were positioned geometrically and allowed to ride on their respective parent atoms [C-H = 0.95 Å and U iso (H) = 1.2U eq (C)]. Nitrogen-bound H atom was located in a difference Fourier map and then allowed to ride on its parent atom in the final cycles of refinement with N-H = 0.92 Å and U iso (H) = 1.5 U eq (N). The highest peak (2.25 eÅ -3 ) and the deepest hole (-0.86 eÅ -3 ) in the difference Fourier map are located 1.25 Å and 1.09 Å from the atoms N4 and C10, respectively.  A structure detail of the title complex, with displacement ellipsoids drawn at the 40% probability level for non-H atoms. where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 2.25 e Å −3 Δρ min = −0.86 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.