Poly[di-μ3-chlorido-di-μ2-chlorido-{μ4-N,N,N′,N′-tetrakis[(diphenylphosphanyl)methyl]benzene-1,4-diamine-κ4 P:P′:P′′:P′′′}tetracopper(II)]

In the title complex, [Cu4Cl4(C58H52N2P4)]n, four CuII atoms are held together via two doubly bridging and two triply bridging chlorides, forming a stair-like Cu4Cl4 core having crystallographically imposed inversion symmetry, while the benzene-1,4-diamine ligand (with a crystallographic inversion center at the centroid) acts in a tetradentate coordination mode, bridging two adjacent Cu4Cl4 cores, resulting in a chain along the a-axis direction. One Cu atom has a distorted tetrahedral geometry, coordinated by one P atom, one μ2-Cl and two μ3-Cl atoms, while the second Cu atom adopts a trigonal geometry, coordinated by one P atom, one μ2-Cl and one μ3-Cl atoms.

In the title complex, [Cu 4 Cl 4 (C 58 H 52 N 2 P 4 )] n , four Cu II atoms are held together via two doubly bridging and two triply bridging chlorides, forming a stair-like Cu 4 Cl 4 core having crystallographically imposed inversion symmetry, while the benzene-1,4-diamine ligand (with a crystallographic inversion center at the centroid) acts in a tetradentate coordination mode, bridging two adjacent Cu 4 Cl 4 cores, resulting in a chain along the a-axis direction. One Cu atom has a distorted tetrahedral geometry, coordinated by one P atom, one 2 -Cl and two 3 -Cl atoms, while the second Cu atom adopts a trigonal geometry, coordinated by one P atom, one 2 -Cl and one 3 -Cl atoms.
The asymmetric unit of the title complex, [Cu 2 Cl 2 (C 29 H 26 NP 2 )] n , contains two copper ions, two chlorine atoms and one half of the N,N,N′,N′-tetrakis[(diphenylphosphanyl)methyl]benzene-1,4-diamine ligand (dpppda). Four copper atoms are held together via two doubly bridging and two triply-bridging chlorides to form a stair-like Cu 4 Cl 4 core having a crystallographically imposed centrosymmetry, while the N,N,N′,N′-tetrakis[(diphenylphosphanyl)methyl]benzene-1,4-diamine ligand (with a crystallographic inversion center at the midpoint of the central phenyl ring) acts as a tetradentate coordination mode to bridge two adjacent Cu 4 Cl 4 cores resulting in a one-dimentional chain. The structure of the title complex is anologous to the reported complex [Cu 4 I 4 (dpppda)] (Li et al., 2009). Cu1 has a distorted tetrahedral geometry, coordinated by one P atom, one µ 2 -Cl and two µ 3 -Cl atoms, while Cu2 adopts a trigonal geometry, coordinated by one P atom, one µ 2 -Cl and one µ 3 -Cl atoms. The mean Cu-Cl and Cu-P bond distances are 2.40 (1) and 2.19 (2) Å, respectively.

Experimental
CuCl (0.0198 g, 0.2 mmol) was added with stirring to a solution of N,N,N′,N′-tetrakis[(diphenylphosphanyl)methyl]benzene-1,4-diamine (0.0900 g, 0.10 mmol) in DMF (5 ml), and the resulting solution was allowed to stir for 1 h at room temperature. Slow diffusion of diethyl ether into the solution give colourless block crystals suitable for X-ray analysis after three days.

Refinement
All hydrogen atoms were generated geometrically with C-H distances of 0.93Å (aromatic H atoms) and 0.97Å (methylene H atoms) and refined with a riding model with U iso (H) = 1.2U eq (C).

Figure 1
The structure of the title compound with displacement ellipsoids drawn at the 20% probability level. Hydrogen atoms are omitted for clarity. [symmetry code:  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