trans-Dichloridobis{dicyclohexyl[4-(dimethylamino)phenyl]phosphane-κP}platinum(II) dichloromethane disolvate

In the title complex, trans-[PtCl2{P(C6H11)2(4-Me2NC6H4)}2]·2CH2Cl2, the PtII atom is located on an inversion centre, resulting in a trans-square-planar geometry. Important geometric parameters are the Pt—P and Pt—Cl bond lengths of 2.3258 (6) and 2.3106 (6) Å, respectively, and the P—Pt—Cl angles of 89.64 (2) and 90.36 (2)°. The effective cone angle for the dicyclohexyl[4-(dimethylamino)phenyl]phosphane unit was calculated to be 164°. The compound crystallizes with two dichloromethane solvent molecules; one of which is severely disordered and was treated using the SQUEEZE routine in PLATON [Spek (2009 ▶). Acta Cryst. D65, 148–155].


trans-Dichloridobis{dicyclohexyl[4-(dimethylamino)phenyl]phosphane-
To describe the steric demand of the phosphane ligands the Tolman cone angle (Tolman, 1977) is still the most commonly used model. Applying this model to the geometry obtained from the title compound (and adjusting the Pt-P bond distance to 2.28 Å) we calculated an effective cone angle (Otto, 2001) of 164°.
The title compound compares well with other closely related Pt II complexes reported in the literature containing two chloride and two tertiary phosphine ligands in a trans geometry (Lutz et al., 2005). The Pt-P and Pt-Cl bond distances of 2.326 (6) and 2.311 (6) Å, respectively for the title compound, fit well into the typical range for complexes of this kind. The title compound crystallizes as a solvated complex which is common for these type of Pt II complexes (Johansson et al., 2002).
The title compound crystallizes with two molecules of dichloromethane. One of these molecules was initially modelled as a severely disordered molecule. We subsequently removed the disordered dichloromethane molecule by applying the SQUEEZE routine as found in PLATON (Spek, 2009).

Experimental
Dichloro ( for methyl H atoms, and = 1.2 for other H atoms. Methyl torsion angles were refined from electron density.
Large thermal motion of one of the dichloromethane solvate molecules, held only by weak intermolecular hydrogen bonding, is observed. This was initially treated anisotropically as distorted over two partially occupied sites generated by symmetry, with atom C4 restrained isotropically. Different disordered models resulted in unstable refinement cycles.
Placement of H atoms on C4 also resulted in unstable refinement. This procedure resulted in unsatisfactory refinements and the molecule was removed by applying the SQUEEZE routine in PLATON (Spek, 2009).

Figure 1
The molecular structure of the title complex, showing the atom numbering and the ordered dichloromethane solvent molecule. The displacement ellipsoids are drawn at the 50% probability level [Symmetry code: (i) -x+3/2, -y+1/2, -z].

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. Highly disordered solvate molecule is observed, resulting in residual electron density around the C4 atom. Different disordered models, however, resulted in unstable refinement cycles. Placement of H atoms on C4 also resulted in unstable refinement. This procedure resulted in unsatisfactory refinements and the molecule was removed by applying the SQUEEZE routine as found in PLATON (Spek, 2003).

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq