Di-μ-chlorido-bis{[2-(morpholinomethyl)phenyl-κ2 C 1,N]palladium(II)}

The title compound, [Pd2(C11H14NO)2Cl2], has a dimeric structure with Cl atoms bridging the two Pd atoms, one half of the molecule being generated by symmetry due to the crystallographic inversion centre located in the middle of the perfectly planar Pd2Cl2 ring. The five-membered ring adopts an envelope conformation, while the morpholino group has a chair conformation. The geometry around the metal centres is distorted square-planar, as a result of a strong intramolecular N→Pd coordination trans to a Pd—Cl bond. In the crystal structure, the dimeric structure is strengthened by intermolecular C—H⋯Cl hydrogen bonds. C—H⋯Cphenyl interactions link the dimers into a columnar supramolecular array along the a axis; the dimers are further connected by C—H⋯Ph interactions into a three-dimensional supramolecular arrangement.

The title compound, [Pd 2 (C 11 H 14 NO) 2 Cl 2 ], has a dimeric structure with Cl atoms bridging the two Pd atoms, one half of the molecule being generated by symmetry due to the crystallographic inversion centre located in the middle of the perfectly planar Pd 2 Cl 2 ring. The five-membered ring adopts an envelope conformation, while the morpholino group has a chair conformation. The geometry around the metal centres is distorted square-planar, as a result of a strong intramolecular N!Pd coordination trans to a Pd-Cl bond. In the crystal structure, the dimeric structure is strengthened by intermolecular C-HÁ Á ÁCl hydrogen bonds. C-HÁ Á ÁC phenyl interactions link the dimers into a columnar supramolecular array along the a axis; the dimers are further connected by C-HÁ Á ÁPh interactions into a three-dimensional supramolecular arrangement.
Financial support from the Romanian Ministry of Education and Research within the programme 'Excellency Research ' (contract No. 19/2006) is greatly appreciated. The authors also thank the National Center for X-ray Diffraction in Cluj-Napoca, Romania, for help with the solid-state structure determinations.
The title compound has a dimeric structure, with two palladacycles bridged through the chlorine atoms, resulting in a perfectly planar Pd 2 Cl 2 core. One half of the molecule is generated by symmetry owing the crystallographic inversion centre located in the middle of the Pd 2 Cl 2 ring. The cycle is distorted from the ideal square as reflected by the diferences in the Pd-Cl bond lengths and the Cl1-Pd1-Cl1 i and Pd1-Cl1-Pd1 i bond angles (Table 1) The N atom from the pendant arm coordinates the metal centre resulting in a square planar (C,N)PdCl 2 core, in which the distortion is mainly due to the PdC 3 N ring constraint. The two equivalent organic ligands from the dimer are in a trans arrangement with respect to the Pd···Pd axis (Fig. 1). The Pd1-C1 [1.971 (2) Å] bond is smaller than the sum of the corresponding covalent radii, its magnitude being similar to those found for related compounds for which partialy Pd-C multiple bond was assumed (Crispini et al., 1992, Fuchita et al., 1999, Mentes et al., 2004).
As a result of the intramolecular coordination of the N1 atom from the organic ligand to Pd1 atom, a nonplanar fivemembered ring is formed, with nitrogen atom lying out of the Pd1/C1/C2/C7 best plane [0.666 (2) Å]. The dihedral angle between the Pd1/N1/C7 and Pd1/C1/C2/C7 planes is 39.2 (1)°. This induces planar chirality (with the aromatic ring and the nitrogen atom as chiral plane and pilot atom, respectively, IUPAC, 1979). In the crystal of the title compound, the dimer contains both R N and S N i isomers.
supplementary materials sup-2 In the crystal structure, the dimer is strengthened by hydrogen-bond type interactions (Table 2) involving the Cl from one molecular unit and the methylenic proton of the morpholinyl group from the other molecular unit from the same dimer [the sum of van der Waals radii of the corresponding atoms Σr vdW (Cl,H) = 3.00 Å; Emsley, 1994] (Fig. 2).
Intermolecular C-H···C phenyl interactions (Table 2) between a methylene hydrogen from the pendant arm and a carbon atom from the aromatic ring of another dimer connect the molecular units in a columnar arrangement along the a axis.
Furthermore, these arrays are interlinked by intermolecular C-H···Ph interactions (Table 2) in a three-dimensional supramolecular arrangement in the crystal structure (Fig.3).

Experimental
For the preparation of the title compound, PdCl 2 (0.1 g, 0.56 mmol) in acetonitrile (40 ml) was refluxed for 3 h, and then allowed to cool to room temperature. A solution of Sb[C 6 H 4 CH 2 {N(CH 2 CH 2 ) 2 O}-2] 3 (0.369 g, 0.56 mmol) in CHCl 3 (35 ml) was added and the mixture was stirred at room temperature for 30 h, under an N 2 atmosphere. The reaction mixture was filtered off and the solvents were removed under vacuum. The yellow oil obtained was triturated with hexane (2 x 20 ml) and then washed with petroleum ether (2 x 10 ml) to give a yellow solid. Yellow crystals suitable for X-ray diffraction studies were obtained by slow diffusion of hexane into a solution of CH 2 Cl 2 of the title compound (1:    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 > 2sigma(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