trans-Dichloridobis[dicyclo­hex­yl(2,4,6-trimethyl­phen­yl)phosphane-κP]palladium(II)

Abstract

The title compound, [PdCl₂(C₂₁H₃₃P)₂], forms a monomeric complex with a trans-square-planar coordination geometry about the Pd^II atom which lies on an inversion centre. The Pd—P bond lengths are 2.3760 (13) Å, while the Pd—Cl bond lengths are 2.3172 (14) Å. The observed structure was found to be closely related to that of trans-dichloridobis[dicyclo­hex­yl(phen­yl)phosphane-κP]palladium(II), [PdCl₂{P(C₆H₁₁)₂(C₆H₅)}₂] [Burgoyne et al. (2012 ▶). Acta Cryst. E68, m404].

Related literature  

For a review on related compounds, see: Spessard & Miessler (1996 ▶). For the synthesis of the starting materials, see: Drew & Doyle (1990 ▶). For similar R—P₂PdCl₂ compounds, see: Ogutu & Meijboom (2011 ▶); Muller & Meijboom (2010a ▶,b ▶). For their applications, see: Bedford et al. (2004 ▶). For the closely related structure of trans-dichloridobis[dicyclo­hex­yl(phen­yl)phos­phane-κP]palladium(II), see: Burgoyne et al. (2012 ▶). For isotypic structures, see: Clarke et al. (2003 ▶); Grushin et al. (1994 ▶); Vuoti et al. (2008 ▶).

Experimental  

Crystal data  

• [PdCl₂(C₂₁H₃₃P)₂]

• M _r = 810.19

• Triclinic,

• a = 9.466 (5) Å

• b = 10.625 (5) Å

• c = 11.527 (5) Å

• α = 63.932 (5)°

• β = 84.500 (5)°

• γ = 75.874 (5)°

• V = 1009.8 (8) ų

• Z = 1

• Mo Kα radiation

• μ = 0.70 mm⁻¹

• T = 100 K

• 0.22 × 0.17 × 0.16 mm

Data collection  

• Bruker APEXII CCD diffractometer

• Absorption correction: multi-scan (SADABS; Bruker, 2007) T _min = 0.861, T _max = 0.896

• 17391 measured reflections

• 4932 independent reflections

• 3385 reflections with I > 2σ(I)

• R _int = 0.082

Refinement  

• R[F ² > 2σ(F ²)] = 0.061

• wR(F ²) = 0.165

• S = 1.02

• 4932 reflections

• 217 parameters

• H-atom parameters constrained

• Δρ_max = 1.05 e Å⁻³

• Δρ_min = −1.93 e Å⁻³

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT-Plus (Bruker, 2007 ▶); data reduction: SAINT-Plus; 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.

Supplementary Material

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

supplementary crystallographic information

Comment

Complexes involving palladium metal centres are amongst some of the most popular catalytic precursors in organic synthesis due to their catalytic abilities. They are used in carbon-carbon bond formation reactions like the Heck, Stille and Suzuki reactions (Bedford et al., 2004).[PdCl₂(L)₂] (L = tertiary phosphine, arsine or stibine) complexes can conveniently be prepared by the substitution of 1,5-cyclooctadiene (COD) from [PdCl₂(COD)]. The title compound, trans-[PdCl₂(C₂₁H₃₃P)₂], crystallizes with the Pd atom on a center of symmetry and each pair of equivalent ligands in a mutually trans orientation.The geometry is,therefore, slightly distorted square planar and the Pd atom is not elevated out of the coordinating atom plane. All angles in the coordination polyhedron are close to the ideal value of 90°, with Cl2—Pd1—P1 = 88.39 (6)° and Cl2—Pd1—P1 = 91.61 (6)°. As required by the crystallographic symmetry, the Cl2—Pd1—Cl2 and P1—Pd1—P1 angles are 180°. The symmetry code used to define atoms through the inversion point is: 1 - x, -y, 1 - z.

The title compound compares well with other closely related PdII complexes from the literature containing two chloro and two tertiary phosphine ligands in a trans geometry (Muller & Meijboom, 2010a, b). The title compound, having a Pd1—Cl2 bond length of 2.3172 (14) Å and a Pd—P bond length of 2.3760 (13) Å, fits well into the typical range for complexes of this kind. Notably the title compound did not crystallize as a solvated complex; these type of PdII complexes have a tendency to crystallize as solvates (Ogutu & Meijboom, 2011).

Notably, the title compound is quintessentially isostructural with: [PdCl₂{P(C₆H₁₁)₃}₂] (Grushin et al., 1994); [PdBr₂{P(C₆H₁₁)₃}₂] (Clarke et al., 2003); and [PdCl₂{P(C₆H₁₁)₂(C₇H₇)}₂] (Vuoti et al., 2008) ((C₆H₁₁) = cyclohexyl, (C₇H₇) = o-tolyl). The Pd–P and Pd–X (X = Br and Cl) bond lengths were compared and it was observed that they were all within the same range of 2.3–2.4 Å. The angles between the bonds around the Pd atom were all observed to be approximately right angles.

Experimental

Dicyclohexyl-(2,4,6 trimethyl phenyl)phosphine (0.11 g, 0.35 mmol) was dissolved in acetone (5cm³). A solution of [Pd(COD)Cl₂] (0.05 g,0.17 mmol) in acetone (5 cm³) was added to the phosphine solution. The mixture was stirred for 5 minutes, after which the solution was left to crystallize. Yellow crystals of the title compound suitable for X-ray diffraction studies were obtained. ¹H NMR (CDCl₃, 400 MHz,p.p.m.): 6.9–6.8(m, 4H), 2.3 (m, 18H),1.5–1.4 (m, 16H),1.5 (m, 8H),1.6 (m, 16H),1.3 (m, 16H), 1.4 (m, 4H).³¹P NMR (CDCl₃, 162.0 MHz, p.p.m.): 80.82. FTIR (cm^-1):2920, 2850, 1713, 1678, 1597, 1553, 1442, 1337, 1074, 998, 883, 846, 728,

Refinement

The aromatic, methine, and methyl H atoms were placed in geometrically idealized positions (C—H = 0.95–0.98) and constrained to ride on their parent atoms, with U_iso(H) = 1.2U_eq(C) for aromatic and methine H atoms, and U_iso(H) = 1.5U_eq(C) for methyl H atoms respectively. Methyl torsion angles were refined from electron density.

Figures

Fig. 1.

The structure of the trans-Dichloridobis[dicyclohexyl-(2,4,6 trimethyl phenyl)phosphane-jP] palladium(II) showing 50% probability displacement ellipsoids. Symmetry code to generate molecule through inversiont point: 1 - x, -y, 1 - z.

Fig. 2.

A perspective of trans-Dichloridobis[dicyclohexyl-(2,4,6 trimethyl phenyl)phosphane-jP] palladium(II) showing the molecular packing modes in the crystals.

Crystal data

C42H66Cl2P2Pd	Z = 1
Mr = 810.19	F(000) = 428
Triclinic, P1	Dx = 1.332 Mg m−3Dm = 1.332 Mg m−3Dm measured by not measured
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71069 Å
a = 9.466 (5) Å	Cell parameters from 3294 reflections
b = 10.625 (5) Å	θ = 2.2–28.3°
c = 11.527 (5) Å	µ = 0.70 mm−1
α = 63.932 (5)°	T = 100 K
β = 84.500 (5)°	Cube, yellow
γ = 75.874 (5)°	0.22 × 0.17 × 0.16 mm
V = 1009.8 (8) Å3

Data collection

Bruker APEXII CCD diffractometer	3385 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.082
φ and ω scans	θmax = 28.3°, θmin = 2.2°
Absorption correction: multi-scan (SADABS; Bruker, 2007)	h = −12→12
Tmin = 0.861, Tmax = 0.896	k = −14→14
17391 measured reflections	l = −15→15
4932 independent reflections

Refinement

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.061	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.165	H-atom parameters constrained
S = 1.02	w = 1/[σ2(Fo2) + (0.0919P)2] where P = (Fo2 + 2Fc2)/3
4932 reflections	(Δ/σ)max < 0.001
217 parameters	Δρmax = 1.05 e Å−3
0 restraints	Δρmin = −1.93 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 F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > 2sigma(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Pd1	0.5	0	0.5	0.02770 (17)
Cl2	0.66664 (12)	0.13206 (13)	0.48974 (13)	0.0403 (3)
P1	0.31238 (11)	0.14874 (12)	0.56557 (10)	0.0279 (3)
C16	0.3797 (5)	0.2560 (5)	0.6307 (4)	0.0332 (10)
C11	0.1511 (6)	0.2214 (6)	0.3425 (5)	0.0420 (12)
H11A	0.0817	0.1659	0.4001	0.05*
H11B	0.2285	0.1549	0.3197	0.05*
C6	0.0268 (5)	0.1246 (5)	0.6872 (5)	0.0363 (11)
C2	0.2357 (5)	−0.0711 (5)	0.7937 (5)	0.0358 (11)
C1	0.1790 (5)	0.0641 (5)	0.6878 (4)	0.0316 (10)
H1	0.1609	0.0137	0.6369	0.038*
C4	−0.0041 (6)	−0.0812 (6)	0.8892 (5)	0.0438 (12)
C21	0.4639 (5)	0.1621 (6)	0.7596 (5)	0.0405 (12)
H21A	0.3976	0.1123	0.8265	0.049*
H21B	0.5438	0.0881	0.7492	0.049*
C17	0.2603 (5)	0.3749 (5)	0.6446 (5)	0.0415 (12)
H17A	0.2087	0.4373	0.5608	0.05*
H17B	0.1885	0.3314	0.7089	0.05*
C15	0.3216 (5)	0.3781 (6)	0.3220 (5)	0.0435 (12)
H15A	0.3587	0.4253	0.3663	0.052*
H15B	0.406	0.3152	0.3018	0.052*
C3	0.1420 (6)	−0.1368 (5)	0.8900 (5)	0.0427 (12)
H3	0.1822	−0.2255	0.9604	0.051*
C12	0.0713 (6)	0.3418 (6)	0.2195 (5)	0.0501 (14)
H12A	0.028	0.2989	0.1747	0.06*
H12B	−0.009	0.4051	0.2434	0.06*
C7	0.3943 (6)	−0.1527 (6)	0.8096 (5)	0.0491 (14)
H7A	0.4314	−0.173	0.894	0.074*
H7B	0.4521	−0.0943	0.7411	0.074*
H7C	0.4014	−0.2434	0.8039	0.074*
C10	0.2180 (5)	0.2864 (5)	0.4122 (4)	0.0300 (9)
H10	0.1369	0.3521	0.4343	0.036*
C18	0.3265 (6)	0.4651 (6)	0.6878 (7)	0.0567 (16)
H18A	0.3939	0.5129	0.6208	0.068*
H18B	0.248	0.5408	0.6971	0.068*
C20	0.5269 (6)	0.2537 (7)	0.8028 (6)	0.0527 (14)
H20A	0.5996	0.2965	0.7393	0.063*
H20B	0.5774	0.1917	0.8871	0.063*
C9	−0.0548 (5)	0.2671 (6)	0.5890 (5)	0.0477 (13)
H9A	−0.155	0.2882	0.6177	0.071*
H9B	−0.056	0.2633	0.5057	0.071*
H9C	−0.0064	0.3428	0.5796	0.071*
C13	0.1717 (7)	0.4301 (6)	0.1292 (5)	0.0555 (15)
H13A	0.1159	0.5087	0.0527	0.067*
H13B	0.2475	0.3689	0.0991	0.067*
C5	−0.0587 (5)	0.0501 (6)	0.7852 (5)	0.0449 (13)
H5	−0.1604	0.0906	0.7816	0.054*
C19	0.4088 (6)	0.3735 (7)	0.8154 (6)	0.0565 (15)
H19A	0.3405	0.3313	0.8844	0.068*
H19B	0.4537	0.434	0.8392	0.068*
C14	0.2432 (6)	0.4931 (6)	0.1962 (5)	0.0517 (14)
H14A	0.1681	0.564	0.2157	0.062*
H14B	0.3144	0.5446	0.1373	0.062*
C8	−0.1042 (7)	−0.1536 (7)	0.9946 (6)	0.0652 (18)
H8A	−0.0615	−0.257	1.038	0.098*
H8B	−0.199	−0.1378	0.9569	0.098*
H8C	−0.1171	−0.1129	1.0575	0.098*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Pd1	0.0255 (3)	0.0175 (3)	0.0286 (3)	0.00253 (18)	0.00010 (18)	−0.00339 (19)
Cl2	0.0323 (6)	0.0314 (6)	0.0560 (8)	−0.0062 (5)	0.0050 (5)	−0.0190 (6)
P1	0.0264 (6)	0.0194 (6)	0.0277 (6)	0.0018 (4)	−0.0007 (4)	−0.0043 (5)
C16	0.034 (2)	0.027 (2)	0.034 (2)	0.0008 (19)	−0.0038 (19)	−0.011 (2)
C11	0.042 (3)	0.035 (3)	0.041 (3)	−0.001 (2)	−0.007 (2)	−0.013 (2)
C6	0.032 (2)	0.032 (3)	0.042 (3)	−0.002 (2)	0.003 (2)	−0.017 (2)
C2	0.037 (2)	0.026 (2)	0.034 (2)	0.0014 (19)	0.0014 (19)	−0.007 (2)
C1	0.036 (2)	0.021 (2)	0.029 (2)	0.0017 (18)	−0.0018 (18)	−0.0067 (18)
C4	0.051 (3)	0.038 (3)	0.046 (3)	−0.021 (2)	0.016 (2)	−0.019 (2)
C21	0.038 (3)	0.037 (3)	0.035 (3)	0.002 (2)	−0.004 (2)	−0.009 (2)
C17	0.035 (2)	0.032 (3)	0.054 (3)	0.001 (2)	−0.002 (2)	−0.020 (2)
C15	0.042 (3)	0.035 (3)	0.031 (2)	−0.003 (2)	−0.003 (2)	0.004 (2)
C3	0.055 (3)	0.030 (3)	0.030 (2)	−0.007 (2)	0.008 (2)	−0.005 (2)
C12	0.051 (3)	0.049 (3)	0.044 (3)	−0.004 (3)	−0.016 (2)	−0.014 (3)
C7	0.049 (3)	0.030 (3)	0.040 (3)	0.013 (2)	0.005 (2)	−0.002 (2)
C10	0.027 (2)	0.024 (2)	0.027 (2)	0.0038 (17)	−0.0026 (17)	−0.0049 (18)
C18	0.046 (3)	0.044 (3)	0.088 (5)	−0.003 (3)	0.004 (3)	−0.040 (3)
C20	0.045 (3)	0.061 (4)	0.051 (3)	−0.001 (3)	−0.008 (3)	−0.028 (3)
C9	0.029 (2)	0.045 (3)	0.047 (3)	0.006 (2)	0.003 (2)	−0.009 (3)
C13	0.065 (4)	0.048 (3)	0.035 (3)	0.002 (3)	−0.013 (3)	−0.006 (3)
C5	0.029 (2)	0.047 (3)	0.057 (3)	−0.008 (2)	0.008 (2)	−0.023 (3)
C19	0.052 (3)	0.069 (4)	0.065 (4)	−0.016 (3)	0.015 (3)	−0.045 (4)
C14	0.051 (3)	0.039 (3)	0.038 (3)	−0.006 (3)	−0.012 (2)	0.007 (2)
C8	0.075 (4)	0.056 (4)	0.062 (4)	−0.024 (3)	0.032 (3)	−0.024 (3)

Geometric parameters (Å, º)

Pd1—Cl2	2.3172 (14)	C15—H15A	0.99
Pd1—Cl2i	2.3172 (14)	C15—H15B	0.99
Pd1—P1	2.3760 (13)	C3—H3	0.95
Pd1—P1i	2.3760 (13)	C12—C13	1.502 (8)
P1—C10	1.859 (4)	C12—H12A	0.99
P1—C16	1.862 (5)	C12—H12B	0.99
P1—C1	1.868 (5)	C7—H7A	0.98
C16—C17	1.532 (6)	C7—H7B	0.98
C16—C21	1.541 (6)	C7—H7C	0.98
C11—C10	1.524 (7)	C10—H10	1
C11—C12	1.536 (7)	C18—C19	1.520 (9)
C11—H11A	0.99	C18—H18A	0.99
C11—H11B	0.99	C18—H18B	0.99
C6—C5	1.382 (7)	C20—C19	1.526 (8)
C6—C1	1.427 (6)	C20—H20A	0.99
C6—C9	1.503 (7)	C20—H20B	0.99
C2—C3	1.393 (6)	C9—H9A	0.98
C2—C1	1.431 (6)	C9—H9B	0.98
C2—C7	1.522 (6)	C9—H9C	0.98
C1—H1	1	C13—C14	1.509 (8)
C4—C3	1.364 (7)	C13—H13A	0.99
C4—C5	1.395 (8)	C13—H13B	0.99
C4—C8	1.510 (7)	C5—H5	0.95
C21—C20	1.522 (8)	C19—H19A	0.99
C21—H21A	0.99	C19—H19B	0.99
C21—H21B	0.99	C14—H14A	0.99
C17—C18	1.526 (7)	C14—H14B	0.99
C17—H17A	0.99	C8—H8A	0.98
C17—H17B	0.99	C8—H8B	0.98
C15—C14	1.534 (6)	C8—H8C	0.98
C15—C10	1.540 (6)
Cl2—Pd1—Cl2i	180	C13—C12—H12B	109.2
Cl2—Pd1—P1	91.61 (6)	C11—C12—H12B	109.2
Cl2i—Pd1—P1	88.39 (6)	H12A—C12—H12B	107.9
Cl2—Pd1—P1i	88.39 (6)	C2—C7—H7A	109.5
Cl2i—Pd1—P1i	91.61 (6)	C2—C7—H7B	109.5
P1—Pd1—P1i	180	H7A—C7—H7B	109.5
C10—P1—C16	103.8 (2)	C2—C7—H7C	109.5
C10—P1—C1	110.9 (2)	H7A—C7—H7C	109.5
C16—P1—C1	104.3 (2)	H7B—C7—H7C	109.5
C10—P1—Pd1	104.11 (15)	C11—C10—C15	110.4 (4)
C16—P1—Pd1	114.10 (15)	C11—C10—P1	112.8 (3)
C1—P1—Pd1	118.79 (15)	C15—C10—P1	110.9 (3)
C17—C16—C21	109.7 (4)	C11—C10—H10	107.5
C17—C16—P1	113.7 (3)	C15—C10—H10	107.5
C21—C16—P1	112.9 (3)	P1—C10—H10	107.5
C10—C11—C12	109.6 (4)	C19—C18—C17	111.6 (5)
C10—C11—H11A	109.7	C19—C18—H18A	109.3
C12—C11—H11A	109.7	C17—C18—H18A	109.3
C10—C11—H11B	109.7	C19—C18—H18B	109.3
C12—C11—H11B	109.7	C17—C18—H18B	109.3
H11A—C11—H11B	108.2	H18A—C18—H18B	108
C5—C6—C1	119.4 (4)	C21—C20—C19	111.7 (5)
C5—C6—C9	114.2 (4)	C21—C20—H20A	109.3
C1—C6—C9	126.4 (4)	C19—C20—H20A	109.3
C3—C2—C1	119.4 (4)	C21—C20—H20B	109.3
C3—C2—C7	115.9 (4)	C19—C20—H20B	109.3
C1—C2—C7	124.7 (4)	H20A—C20—H20B	107.9
C6—C1—C2	117.3 (4)	C6—C9—H9A	109.5
C6—C1—P1	125.7 (3)	C6—C9—H9B	109.5
C2—C1—P1	116.9 (3)	H9A—C9—H9B	109.5
C6—C1—H1	90.7	C6—C9—H9C	109.5
C2—C1—H1	90.7	H9A—C9—H9C	109.5
P1—C1—H1	90.7	H9B—C9—H9C	109.5
C3—C4—C5	116.5 (4)	C12—C13—C14	110.5 (5)
C3—C4—C8	123.1 (5)	C12—C13—H13A	109.6
C5—C4—C8	120.4 (5)	C14—C13—H13A	109.6
C20—C21—C16	110.7 (4)	C12—C13—H13B	109.6
C20—C21—H21A	109.5	C14—C13—H13B	109.6
C16—C21—H21A	109.5	H13A—C13—H13B	108.1
C20—C21—H21B	109.5	C6—C5—C4	123.7 (5)
C16—C21—H21B	109.5	C6—C5—H5	118.2
H21A—C21—H21B	108.1	C4—C5—H5	118.2
C18—C17—C16	110.3 (4)	C18—C19—C20	109.5 (5)
C18—C17—H17A	109.6	C18—C19—H19A	109.8
C16—C17—H17A	109.6	C20—C19—H19A	109.8
C18—C17—H17B	109.6	C18—C19—H19B	109.8
C16—C17—H17B	109.6	C20—C19—H19B	109.8
H17A—C17—H17B	108.1	H19A—C19—H19B	108.2
C14—C15—C10	110.9 (4)	C13—C14—C15	112.5 (5)
C14—C15—H15A	109.4	C13—C14—H14A	109.1
C10—C15—H15A	109.4	C15—C14—H14A	109.1
C14—C15—H15B	109.4	C13—C14—H14B	109.1
C10—C15—H15B	109.4	C15—C14—H14B	109.1
H15A—C15—H15B	108	H14A—C14—H14B	107.8
C4—C3—C2	123.7 (5)	C4—C8—H8A	109.5
C4—C3—H3	118.1	C4—C8—H8B	109.5
C2—C3—H3	118.1	H8A—C8—H8B	109.5
C13—C12—C11	111.8 (5)	C4—C8—H8C	109.5
C13—C12—H12A	109.2	H8A—C8—H8C	109.5
C11—C12—H12A	109.2	H8B—C8—H8C	109.5

Symmetry code: (i) −x+1, −y, −z+1.