Bis[(diphenylphosphanylmethyl)diphenylphosphane sulfide-κ2 P,S]copper(I) hexafluoridophosphate

In the title compound, [Cu(C25H22P2S)2]PF6, the CuI atom, lying on a twofold rotation axis, adopts a distorted tetrahedral geometry. The (diphenylphosphanylmethyl)diphenylphosphane sulfide ligand coordinates to the CuI atom through one S and one P atom, forming a stable five-membered chelate ring. The P atom of the PF6 − anion also lies on a twofold rotation axis.

In the title compound, [Cu(C 25 H 22 P 2 S) 2 ]PF 6 , the Cu I atom, lying on a twofold rotation axis, adopts a distorted tetrahedral geometry. The (diphenylphosphanylmethyl)diphenylphosphane sulfide ligand coordinates to the Cu I atom through one S and one P atom, forming a stable five-membered chelate ring. The P atom of the PF 6 À anion also lies on a twofold rotation axis.

Experimental
Crystal data [Cu(C 25  Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL. The chemistry of copper(I) remains on the forefront in binding to soft Lewis bases such as phosphorous and sulfur donors (Liaw et al., 2005;Zhang et al., 2005). For examples, there are a number of published studies of structures that involve copper(I) complexes with phosphane ligands in variable copper(I)-to-ligand ratios (Bownaker et al., 1995;Comba et al., 1999). Mononuclear and dinuclear phosphane-copper(I) complexes with coordinated and bridging halide anions and phosphane ligands in various coordination modes have been well isolated and structurally characterized (Lobana et al., 2009). Quite a few copper(I) complexes with mixed phosphane and sulfide ligands have been synthesized and structurally measured by X-ray crystallography (Lobana et al., 2009;Nicola et al., 2005). Although adducts of bis(diphenylphosphanyl)methane (dppm), structurally defined complexes of the form CuX:dppm (1:1) (X = Cl, Br, I, CN, SCN), have been well documented (Nicola et al., 2005), only one example of mononuclear copper(I) complex with (diphenylphosphanylmethyl)diphenylphosphane sulfide (dppmS) that involves in oxidation of one phosphorus atom of the dppm ligand to P=S moiety has been reported (Sivasankar et al., 2004). The second example of mononuclear copper(I) complex with dppmS ligands is described in this paper.
The title compound consists of a cationic [Cu(dppmS) 2 ] + unit and a PF 6anion (Fig. 1). The dppmS ligand coordinates to the Cu I atom with one S and one P atoms, forming a stable five-membered chelating ring. The coordinating environment around the Cu I atom is distorted tetrahedral. The Cu-P bond length (Table 1) is similar to those found in [Cu(dppmS) 2 ][ClO 4 ] (Sivasankar et al., 2004) and in the copper(I)-dppm complexes (Bera et al., 1999). The Cu-S bond length of 2.411 (3) Å agrees well with that of 2.395 (3) Å in [Cu(dppmS) 2 ][ClO 4 ] (Sivasankar et al., 2004). The P-Cu-P bond angle of 127.60 (11)° is obviously larger than the S-Cu-S bond angle of 101.63 (11)°, due to the bulky PPh 2 moiety directly binding to the Cu atom. The P-Cu-S bond angle of 97.37 (6)° in the five-membered ring of the dppmS ligand is more acute than that of 115.45 (5)° between two dppmS ligands. The PF 6anion has its expected structure as well as normal distances and angles.

Experimental
To a solution of [Cu(CH 3 CN) 4 ][PF 6 ] (373 mg, 1.0 mmol) in CH 3 CN (10 ml) was added with a dppm (796 mg, 2.0 mmol) solution in CH 2 Cl 2 (5 ml) and S 8 powder (64 mg, 2.0 mmol). After the mixture was stirred for 4 h at room temperature, the colorless solution with a little brown precipitate was obtained. After filtration, colorless block crystals were formed by slow evaporation of the filtrate at room temperature in three days. Refinement H atoms were positioned geometrically and refined as riding atoms, with C-H = 0.93 (aromatic) and 0.97 (CH 2 ) Å and with U iso (H) = 1.2U eq (C).

Figure 1
Molecular structure of the title compound, with displacement ellipsoids at the 50% probability level. [Symmetry codes:  where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 0.41 e Å −3 Δρ min = −0.55 e Å −3 Special details Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 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.