Chlorido{[2-(dicyclohexylphosphanoyl)ethyl]bis[2-(dicyclohexylphosphanyl)ethyl]phosphane}platinum(II) chloride dichloromethane hemisolvate tetrahydrate

The title compound, [PtCl(C42H78OP4)]Cl·0.5CH2Cl2·4H2O, crystallizes as a contact ion-pair with two close intermolecular C—H⋯Cl− contacts between CH acidic αH atoms of the phosphane ligand and the chloride anion. A chloride ligand together with three coordinating P ligand atoms create a slightly distorted square-planar coordination environment around the PtII center. An intermolecular water O—H⋯Cl− and water O—H⋯OP hydrogen-bond network completes the coordination around the anion. In addition, a disordered CH2Cl2 solvent molecule cocrystallized within a hydrophobic cavity spanned by the dicyclohexylphosphane ligands.

The title compound, [PtCl(C 42 H 78 OP 4 )]ClÁ0.5CH 2 Cl 2 Á4H 2 O, crystallizes as a contact ion-pair with two close intermolecular C-HÁ Á ÁCl À contacts between CH acidic H atoms of the phosphane ligand and the chloride anion. A chloride ligand together with three coordinating P ligand atoms create a slightly distorted square-planar coordination environment around the Pt II center. An intermolecular water O-HÁ Á ÁCl À and water O-HÁ Á ÁOP hydrogen-bond network completes the coordination around the anion. In addition, a disordered CH 2 Cl 2 solvent molecule cocrystallized within a hydrophobic cavity spanned by the dicyclohexylphosphane ligands.

Experimental
Crystal data [PtCl(C 42   Hydrogen-bond geometry (Å , ).  Figure 1). The Pt II centre is tetracoordinated revealing a slightly distorted square-planar coordination geometry (Brüggeller et al., 1992). The phosphane oxide group of the ligand is not coordinated to the Pt II centre in the solid state (Rieckborn et al., 2008).

S2. Experimental
Unless otherwise stated all reactions were conducted under Schlenk techniques. Solvents were dried and stored under nitrogen.
Potassium tetrachloroplatinate(II) (215 mg, 0.52 mmol), was dissolved in 30 ml water and 30 ml e thanol was added. 367 mg (0.52 mmol) of Tris(2-(dicyclohexylphosphino)-ethyl)phosphane was dissolved in 15 ml dichloromethane and added to the reaction mixture. The colourless suspension was stirred at room temperature for 3 days. Afterwards the mixture was concentrated to small volume and a colourless solid precipitated. The precipitate was filtered and dried in vacuo. Single crystals were received by diffusion of n-hexane into a solution of the product in dichloromethane in air.

S3. Refinement
All non-hydrogen atoms were refined with anisotropic temperature parameters and H atoms were refined using a riding model with C-H distances set to 0.99 Å for aliphatic, and 0.80 Å for water O-H bonds. U iso (H) values were set to 1.2 U~eq~ for carbon bonded and to 1.5 U~eq~ for oxygen bonded H atoms of the parent atom. The dichloromethane molecule has been refined using half of a molecule of dichloromethane disordered over two sites with relative  Representation of the Pt(II) complex with displacement ellipsoids at 50% probability. H atoms of the cyclohexyl and ethylene groups have been omitted for clarity. The hydrogen bonds between the anion and water molecules and the C-H groups respectively are depicted as dashed lines.

Data collection
Bruker SMART APEX CCD area-detector diffractometer Radiation source: fine-focus sealed tube Graphite monochromator φ and ω scans Absorption correction: multi-scan (SADABS; Sheldrick, 1996) T min = 0.694, T max = 0.804 33754 measured reflections 11635 independent reflections 7471 reflections with I > 2σ(I) Special details Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s 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 > 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.