Crystal structure of bis[μ-1,4-bis(diphenylphosphanyl)butane-κ2 P:P′]bis[(3,4,7,8-tetramethyl-1,10-phenanthroline-κ2 N,N′)copper(I)] bis(hexafluoridophosphate) dichloromethane disolvate

The crystal structure of a dinuclear copper(I) complex bearing bridging 1,4-bis(diphenylphosphanyl)butane and 3,4,7,8-tetramethyl-1,10-phenanthroline ligands is described.


Structural commentary
The asymmetric unit of the title compound consists of half of the dicopper(I) complex cation, one hexafluoridophosphate ISSN 2056-9890 counter-anion, and one dichloromethane molecule. The complex has crystallographically imposed inversion symmetry. Each copper(I) atom is coordinated in a distorted tetrahedral geometry by two nitrogen atoms of a chelating tmp molecule and two phosphorus atoms of two centrosymmetric bridging dppb ligands, forming a 14-membered ring (Fig. 1).

Supramolecular features
In the crystal,interactions between the phenanthroline rings of adjacent complex dications are observed [centroid-tocentroid distance = 3.644 (4) Å ], forming chains running parallel to [111]. As shown in Fig. 2, the dichloromethane solvent molecules and counter-ions are sandwiched by the chains of the complex cations. There are weak intermolecular C-HÁ Á ÁF hydrogen-bonding interactions between the fluorine atoms of the counter-ion and the methylene group of the dichloromethane molecule. An intermolecular C-HÁ Á ÁF hydrogen bond involving an aromatic C-H group of a phenyl ring is also observed ( Table 1). Intermolecularinteractions between phenanthroline rings are not observed in the crystal structure of [Cu 2 (dmp) 2 (dppb) 2 ](PF 6 ) 2 , where only weak intramolecular interactions are present between the phenanthroline ring and the phenyl rings of the diphosphine moieties.

Figure 2
The packing of the title compound, viewed along the a axis.

Synthesis and crystallization
Under an argon atmosphere, [Cu(MeCN) 4 ]PF 6 (75 mg, 0.20 mmol) was added to a CH 2 Cl 2 solution of dppb (85 mg, 0.20 mmol). Then, tmp (45 mg, 0.20 mmol) was added and the reaction mixture was stirred for 100 min at room temperature. After addition of n-hexane to the solution, the formed solid was filtered, washed with diethyl ether, and dried in vacuo (yield; 139 mg, 80%). Single crystals of the title compound suitable for X-ray analysis were obtained by slow diffusion of diethyl ether into the dichloromethane solution.

Refinement
Data collection details and refinement results are summarized in Table 2. All H atoms were positioned geometrically and refined using a riding model with C-H = 0.99 Å and U iso (H) = 1.2U eq (C) for methylene groups, C-H = 0.98 Å and U iso (H) = 1.2U eq (C) for the methyl groups and C-H = 0.95 Å and U iso (H) = 1.2U eq (C) for the aromatic groups. A rotation model was used for the methyl groups.  ; program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: Mercury (Macrae et al., 2008); software used to prepare material for publication: publCIF (Westrip, 2010).