[4-Bromo-N-(pyridin-2-ylmethylidene)aniline-κ2 N,N′]iodido(triphenylphosphane-κP)copper(I)

In the title compound, [CuI(C12H9BrN2)(C18H15P)], the CuI ion is bonded to one I atom, one triphenylphosphane P atom and two N atoms of the diimine ligand in a distorted tetrahedral geometry. The Schiff base acts as a chelating ligand and coordinates to the CuI atom via two N atoms. In the diimine ligand, the dihedral angle between the pyridine and bromophenyl rings is 19.2 (2)°. In the crystal, molecules are connected by π–π stacking interactions between inversion-related pyridine rings [centroid–centroid distance = 3.404 (3) Å].

In the title compound, [CuI(C 12 H 9 BrN 2 )(C 18 H 15 P)], the Cu I ion is bonded to one I atom, one triphenylphosphane P atom and two N atoms of the diimine ligand in a distorted tetrahedral geometry. The Schiff base acts as a chelating ligand and coordinates to the Cu I atom via two N atoms. In the diimine ligand, the dihedral angle between the pyridine and bromophenyl rings is 19.2 (2) . In the crystal, molecules are connected bystacking interactions between inversionrelated pyridine rings [centroid-centroid distance = 3.404 (3) Å ].
The molecular structure with the atom-numbering scheme is presented in Fig. 1, and the bond lengths (Allen et al., 1987) and angles are generally normal. The copper(I) is coordinated by two nitrogen atoms of the bidentate Schiff-base ligand, one P atom of triphenylphosphane and one I atom. Although a tetrahedral geometry might be expected for a four coordinate copper(I) centre, the geometry around the copper(I) ion is distorted by the restricting bite angle N1-Cu1-N2 [79.3 (2)°] of the chelating Schiff-base ligand.

Experimental
To a stirring solution of 190 mg (1 mmol) CuI in 5 ml of acetonitrile was added dropwise 263 mg (1 mmol) of triphenylphosphane in 5 ml acetonitrile. The mixture was stirred for 30 min and then 261 mg (1 mmol) of ligand, 4-bromophenylpyridine-2-ylmethyleneamine, in 10 ml acetonitrile was added and stirred for an additional 20 min. The volume of the solvent was reduced under vacuum to about 5 ml. The diffusion of diethyl ether vapor into the concentration solution gave dark red crystals. The crystals were filtered off and washed with Et 2 O. Yield: 65%. Anal. Calc. for C 30 H 24 N 2 CuPBrI: C, 50.48; H, 3.38; N, 3.93%. Found: C, 50.55; H, 3.51; N, 3.78%.

Refinement
All hydrogen atoms were positioned geometrically and treated as riding on their parent atoms. The isotropic atomic displacement parameters of hydrogen atoms were evaluated as 1.2×U eq of the parent atom.

Figure 1
Molecular structure of the title compound. Displacement ellipsoids are drawn at the 50% probability level.

Special details
Experimental. CrysAlisPro (Agilent, 2010) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm. Refinement. The refinement was carried out against all reflections. The conventional R-factor is always based on F. The goodness of fit as well as the weighted R-factor are based on F and F 2 for refinement carried out on F and F 2 , respectively. The threshold expression is used only for calculating R-factors etc. and it is not relevant to the choice of reflections for refinement. The program used for refinement, Jana2006, uses the weighting scheme based on the experimental expectations, see _refine_ls_weighting_details, that does not force S to be one. Therefore the values of S are usually larger than the ones from the SHELX program.