Acetonitrile­[2-(1-{bis­[2,4,6-tris­(trifluoro­meth­yl)phen­yl]phosphan­yloxy}-1-methyl­eth­yl)pyridine]­methyl­palladium(II) hexa­fluoridoanti­monate dichloro­methane hemisolvate

Liuzhong Li; Peter S White; Aiyou Hao

doi:10.1107/S1600536811005277

. 2011 Feb 23;67(Pt 3):m365. doi: 10.1107/S1600536811005277

Acetonitrile[2-(1-{bis[2,4,6-tris(trifluoromethyl)phenyl]phosphanyloxy}-1-methylethyl)pyridine]methylpalladium(II) hexafluoridoantimonate dichloromethane hemisolvate

Liuzhong Li ^a,^b, Peter S White ^b, Aiyou Hao ^a,^*

PMCID: PMC3051981 PMID: 21522289

Abstract

In the title compound, [Pd(CH₃)(C₂₆H₁₄F₁₈NOP)(C₂H₃N)][SbF₆]·0.5CH₂Cl₂, the Pd²⁺ cation has a distorted square-planar environment, being coordinated by the acetonitrile [Pd—N = 2.078 (8) Å] and methyl [Pd—C = 2.052 (9) Å] groups and the bidentate ligand 2-(1-{bis[2,4,6-tris(trifluoromethyl)phenyl]phosphanyloxy}-1-methylethyl)pyridine (L). In L, one –CF₃ group is rotationally disordered between two orientations in a 1:1 ratio. The solvent molecule was treated as disordered between two positions related by an inversion center with occupancies fixed at 0.5. The crystal packing exhibits weak intermolecular C—H⋯F contacts.

Related literature

For general background to the chemistry of phosphine-imine ligands and palladium complexes, see: Batsanov et al. (2002 ▶); Chen et al. (2003 ▶); Doherty et al. (2007 ▶); Flapper et al. (2009a ▶,b ▶); Guan & Marshall (2002 ▶); Kermagoret & Braunstein (2008 ▶); Speiser et al. (2004 ▶).

Experimental

Crystal data

[Pd(CH₃)(C₂₆H₁₄F₁₈NOP)(C₂H₃N)][SbF₆]·0.5CH₂Cl₂
M _r = 1170.05
Triclinic,
a = 8.8635 (8) Å
b = 12.1336 (12) Å
c = 19.107 (2) Å
α = 79.166 (8)°
β = 80.147 (8)°
γ = 78.266 (8)°
V = 1957.2 (3) Å³
Z = 2
Cu Kα radiation
μ = 11.56 mm⁻¹
T = 100 K
0.15 × 0.10 × 0.05 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: numerical (SADABS; Bruker, 2007 ▶) T _min = 0.276, T _max = 0.596
12653 measured reflections
6232 independent reflections
4802 reflections with I > 2σ(I)
R _int = 0.052

Refinement

R[F ² > 2σ(F ²)] = 0.066
wR(F ²) = 0.191
S = 1.02
6232 reflections
590 parameters
63 restraints
H-atom parameters constrained
Δρ_max = 2.34 e Å⁻³
Δρ_min = −0.95 e Å⁻³

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

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811005277/cv5026sup1.cif

e-67-0m365-sup1.cif^{(36.6KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811005277/cv5026Isup2.hkl

e-67-0m365-Isup2.hkl^{(305KB, hkl)}

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

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C4—H4B⋯F1ⁱ	0.98	2.40	3.365 (13)	166
C12—H12⋯F5ⁱ	0.95	2.60	3.276 (11)	129
C4—H4A⋯F4	0.98	2.53	3.464 (13)	158
C4—H4C⋯F2ⁱⁱ	0.98	2.30	3.225 (13)	155
C11—H11C⋯F5ⁱⁱⁱ	0.98	2.49	3.352 (11)	146

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) .

Acknowledgments

We thank Professor Maurice S. Brookhart for helpful discussions.

supplementary crystallographic information

Comment

The oligomerization of ethylene is one of the most important industrial processes to obtain linear alpha-olefins (Chen et al., 2003; Guan et al.,2002). Bidentate phosphine-imine ligands (P^N ligands) have attracted considerable concerns in the field of transition metal catalysis. Palladium and nickel complexes with P^N ligands have been widely applied in the oligomerization and polymerization of ethylene(Doherty et al., 2007; Flapper et al., 2009a,b; Kermagoret et al., 2008; Speiser et al., 2004). Herein, we report the synthesis and characterization of cationic palladium complex, with electron-poor bulky ligand bearing tris(trifluoromethyl) phenyl phosphine, which can be synthesized according to the literature (Batsanov et al., 2002; Speiser et al., 2004), [(CH₃N)(CH₃)LPd]⁺ [SbF₆]^- 0.5(CH₂Cl₂), where L = [2-ethyl-(1'-methyl-1'-oxy(bis(2,4,6-tris(trifluoromethyl) phenyl)phosphino)]pyridine.

In the title compound, each Pd center has a distorted square-planar environment being coordinated by acetonitrile [Pd—N 2.078 (8) Å], methyl [Pd—C 2.052 (9) Å] and bidentate ligand L. In L, one CF₃ group is rotationally disordered between two orientations in a ratio 1:1. The solvent molecule has been treated as disordered between two positions related by inversion center with occupancies fixed to 0.5 each. The crystal packing exhibits weak intermolecular C—H···F contacts (Table 1).

Experimental

All manipulations of air- and/or moisture-sensitive compounds were conducted using standard Schlenk techniques. Argon was purified by passage through columns of BASF R3–11 catalyst (Chemalog) and 4Å molecular sieves. All solvents were deoxygenated, dried and distilled using common techniques. 2-Pyridin-2-ylpropan-2-ol and di[tris(trifluoromethyl)phenyl]phosphine chloride were prepared according to the literature procedures(Batsanov et al., 2002; Speiser et al., 2004). A flame-dried Schlenk flask was charged with 2-pyridin-2-ylpropan-2-ol (280 mg, 1.30 mmol) and dried THF (5 ml). The solution was cooled to -78°C, and 2.5 mol/l n-BuLi in hexane (0.52 ml, 1.30 mmol) was added slowly. After stirring of 2.0 hrs at -78°C, 800 mg in THF(2 ml) was added slowly. Stirring for 1 day, 30 ml degassed saturated NaCl solution was charged for hydrolysis. After separation, dry and column purification, the ligand of 2-ethyl-[1'-methyl-1'-oxy(di(2, 4, 6-tris(trifluoromethyl) phenyl)phosphino)] pyridine was obtained. The cationic complex was prepared by reaction of the above ligand (1.0 equiv.), (COD)PdMeCl (1.0 equiv.), and AgSbF₆ (1.0 equiv.) at RT, and the single-crystal was cultivated by recrystallization of CH₂Cl₂ and pentane. Calcd for C29H20F24N2OPPdSb: C, 30.89; H, 1.79; N, 2.48. Found: C, 30.89; H, 1.59; N, 2.21.