Dichlorido{[(diphenylphosphino)methyl]bis(2-methylphenyl)phosphine-κ2 P,P′}palladium(II)

In the title compound, [PdCl2(C27H26P2)] or PdCl2[(C6H5)2PCH2P(C6H4CH3)2], the palladium center has a distorted square-planar geometry. There are two crystallographically independent molecules in the asymmetric unit. The dihedral angle between the PdP2 and PdCl2 planes is 2.95 (4)° in one independent molecule and 5.15 (4)° in the other. The P—Pd—P and P—C—P bond angles are significantly distorted because of the small bite angle of the chelating (bisphosphino)methane ligand. The steric demands of the substituted rings in the mixed ligand cause a slight elongation of the Pd—P(C6H4CH3)2 bond relative to the Pd—P(C6H5)2 bond. In one molecule the tolyl ring shows positional disorder in a 0.58 (2):0.42 (2) ratio, in the other molecule the phenyl ring shows positional disorder in a 0.838 (9):0.162 (9) ratio.

In the title compound, [PdCl 2 (C 27 H 26 P 2 )] or PdCl 2 [(C 6 H 5 ) 2 -PCH 2 P(C 6 H 4 CH 3 ) 2 ], the palladium center has a distorted square-planar geometry. There are two crystallographically independent molecules in the asymmetric unit. The dihedral angle between the PdP 2 and PdCl 2 planes is 2.95 (4) in one independent molecule and 5.15 (4) in the other. The P-Pd-P and P-C-P bond angles are significantly distorted because of the small bite angle of the chelating (bisphosphino)methane ligand. The steric demands of the substituted rings in the mixed ligand cause a slight elongation of the Pd-P(C 6 H 4 CH 3 ) 2 bond relative to the Pd-P(C 6 H 5 ) 2 bond. In one molecule the tolyl ring shows positional disorder in a 0.58 (2):0.42 (2) ratio, in the other molecule the phenyl ring shows positional disorder in a 0.838 (9):0.162 (9) ratio.
Single crystals suitable for X-ray diffraction were grown from slow diffusion of pentane into a concentrated CH 2 Cl 2 solution at room temperature.

S3. Refinement
The proposed structural model consisting of two independent host molecules that each exhibit disorder off of the phosphines was developed. The positional disorder present in molecule 1 (Fig. 1) is located on the ortho-tolyl ring that contains C1 to C7. The disordered ortho-tolyl rings were restrained to have similar P-C bond distances, the same geometries, and to be flat using an effective standard deviation (e.s.d.) for each restraint of 0.01 Å. The final refinement showed that the ortho-tolyl ring is located in the primary position 57.8 (20)% of the time. The disorder present in molecule 2 ( Fig. 1) is located on the phenyl ring that contains C43 to C48. The disordered phenyl rings were restrained to have similar P-C bond distances, similar C-C bond distances across the ring, and to be flat using e.s.d.'s of 0.01. The final refinement showed only a slight disorder in the phenyl ring with the primary position being 83.83 (9)% occupied.
Anti bumping restraints were also used to prevent close contacts between the H atoms on the P-C-P bridged carbon and the ortho H atoms on the phenyl rings. Rigid-bond restraints (e.s.d. 0.01) were imposed on displacement parameters for all disordered sites and similar displacement amplitudes (e.s.d. 0.01) were imposed on disordered sites overlapping by less than the sum of Van der Waals radii. Methyl H atom positions, R-CH 3 , were optimized by rotation about R-C bonds with idealized C-H, R-H and H···H distances (C-H = 0.9800 and H···H = 1.6000 Å). Remaining H atoms were included as riding idealized contributors (aromatic C-H = 0.9500 Å, and R 2 CH 2 C-H = 0.9900 Å). Methyl H atom U's were assigned as 1.5 times U eq of the carrier atom; remaining H atom U's were assigned as 1.2 times carrier U eq .

Figure 1
Two independent molecular structures of the title compound in the asymmetric unit showing disorder of the ortho-tolyl ring C1 to C7 in molecule 1 (left) and the phenyl ring C43 to C48 in molecule 2 (right) with 35% probability ellipsoids for non-H atoms and circles of arbitrary size for H atoms.  Molecule 1 of the title compound showing 35% probability ellipsoids for non-H atoms and circles of arbitrary size for H atoms. Disorder of the ortho-tolyl ring C1 to C7 has been omitted for clarity.

Figure 3
Molecule 2 of the title compound showing 35% probability ellipsoids for non-H atoms and circles of arbitrary size for H atoms. Disorder of the phenyl ring C43 to C48 has been omitted for clarity.  where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max = 0.006 Δρ max = 0.66 e Å −3 Δρ min = −0.47 e Å −3 Special details Experimental. One distinct cell was identified using APEX2 (Bruker, 2004). Six frame series were integrated and filtered for statistical outliers using SAINT (Bruker, 2005) then corrected for absorption by integration using SHELXTL/XPREP V2005/2 (Bruker, 2005) before using SAINT/SADABS (Bruker, 2007) to sort, merge, and scale the combined data. No decay correction was applied. 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. Structure was phased by direct methods (Sheldrick, 2008). Systematic conditions suggested the unambiguous space group. The space group choice was confirmed by successful convergence of the full-matrix leastsquares refinement on F 2 . The highest peaks in the final difference Fourier map were in the vicinity of atoms Pd2, Cl4, C48, and C54; the final map had no other significant features. A final analysis of variance between observed and calculated structure factors showed some dependence on amplitude and little dependence on resolution.  (4)