(Acridine-κN)(pyridine-2,6-dicarboxylato-κ3 O 2,N,O 6)palladium(II)

In the title complex, [Pd(C7H3NO4)(C13H9N)], the PdII ion is four-coordinated in a distorted square-planar environment by one N and two O atoms from the tridentate pyridine-2,6-dicarboxylate (dipic) anionic ligand and one N atom of the acridine (acr) ligand. The dipic and acr ligands are nearly planar [maximum deviation = 0.069 (3) Å in dipic and 0.091 (4) Å in acr] and the dihedral angle between their mean planes is 58.67 (7)°. The Pd—O bond lengths are nearly equal, but the Pd—N bond lengths are slightly different. There is a short C—H⋯O interaction in the molecule involving the two ligands. In the crystal, complex molecules are linked through C—H⋯O interactions, forming a three-dimensional network. There are also a number of intermolecular π–π interactions present, the shortest ring centroid–centroid distance being 3.622 (3) Å.

In the title complex, [Pd(C 7 H 3 NO 4 )(C 13 H 9 N)], the Pd II ion is four-coordinated in a distorted square-planar environment by one N and two O atoms from the tridentate pyridine-2,6dicarboxylate (dipic) anionic ligand and one N atom of the acridine (acr) ligand. The dipic and acr ligands are nearly planar [maximum deviation = 0.069 (3) Å in dipic and 0.091 (4) Å in acr] and the dihedral angle between their mean planes is 58.67 (7) . The Pd-O bond lengths are nearly equal, but the Pd-N bond lengths are slightly different. There is a short C-HÁ Á ÁO interaction in the molecule involving the two ligands. In the crystal, complex molecules are linked through C-HÁ Á ÁO interactions, forming a three-dimensional network. There are also a number of intermolecularinteractions present, the shortest ring centroid-centroid distance being 3.622 (3) Å .

Related literature
For the crystal structure of the related Pt II complex [Pt(C 7 H 3 NO 4 )(C 13 H 9 N)], see: Ha (2011).

Kwang Ha Comment
The title complex is isomorphous with the previously reported analogous Pt II complex [Pt(dipic)(acr)] (Ha, 2011).
In the title complex, the Pd II ion is four-coordinated in a distorted square-planar environment by one N and two O atoms from the tridentate pyridine-2,6-dicarboxylate (dipic) anionic ligand and one N atom of the acridine (acr) ligand (Fig. 1).  Table 1). The dipic and acr ligands are nearly planar [maximum deviation = 0.069 (3) Å in dipic and 0.091 (4) Å in acr] and the dihedral angle between the least-squares planes of the two ligands is 58.67 (7)°. In the molecule, there is a short C19-H19···O3 interaction involving the two ligands.

Experimental
To a solution of acridine (0.0898 g, 0.501 mmol) in EtOH (20 ml) and MeOH (10 ml) were added pyridine-2,6-dicarboxylic acid (0.0838 g, 0.501 mmol) and Na 2 PdCl 4 (0.1465 g, 0.498 mmol) and stirred for 3 h at room temperature. After addition of H 2 O (10 ml) to the reaction mixture, the formed precipitate was separated by filtration, washed with EtOH and ether, and dried at 333 K, to give a yellow powder (0.1546 g). Block-like yellow crystals, suitable for X-ray analysis, were obtained by slow evaporation of an acetone solution.

Refinement
H atoms were positioned geometrically and allowed to ride on their respective parent atoms: C-H = 0.95 Å with U iso (H) = 1.2U eq (C). The highest peak (1.21 e Å -3 ) and the deepest hole (-1.14 e Å -3 ) in the difference Fourier map are located 1.38 Å and 0.99 Å, respectively, from the Pd1 atom.   where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max = 0.001 Δρ max = 1.21 e Å −3 Δρ min = −1.14 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