Chlorido(1,2-dimethyl-1H-imidazole-κN 3){2-[(diphen­oxy­phosphan­yl)­oxy]phenyl-κ2 C 1,P}palladium(II)

Izabela Błaszczyk; Anna M Trzeciak; Andrzej Gniewek

doi:10.1107/S1600536812003431

. 2012 Jan 31;68(Pt 2):m227–m228. doi: 10.1107/S1600536812003431

Chlorido(1,2-dimethyl-1H-imidazole-κN ³){2-[(diphenoxyphosphanyl)oxy]phenyl-κ² C ¹,P}palladium(II)

Izabela Błaszczyk ^a, Anna M Trzeciak ^a, Andrzej Gniewek ^a,^*

PMCID: PMC3274940 PMID: 22346887

Abstract

The Pd atom in the title compound, [Pd(C₁₈H₁₄O₃P)Cl(C₅H₈N₂)], adopts a slightly distorted square-planar coordination geometry, with the metallated carbon positioned trans to the Cl atom. The crystal structure is stabilized by several weak C—H⋯O and C—H⋯Cl hydrogen-bond interactions. One of the phenyl rings is disordered over two almost equally occupied sites.

Related literature

The structure of the title compound was determined as part of a larger study on orthopalladated triarylphosphite complexes. For related structures and further discussion, see: Albinati et al. (1990 ▶); Błaszczyk et al. (2011 ▶). For the catalytic reactions, see: Miyaura et al. (1981 ▶); Sonogashira et al. (1975 ▶). For bond lengths in coordination complexes, see: Orpen et al. (1989 ▶). For hydrogen-bond interactions, see: Aullón et al. (1998 ▶); Desiraju & Steiner (1999 ▶). For details of the temperature control applied during data collection, see: Cosier & Glazer (1986 ▶); and for specifications of analytical numeric absorption correction, see: Clark & Reid (1995 ▶).

Experimental

Crystal data

[Pd(C₁₈H₁₄O₃P)Cl(C₅H₈N₂)]
M _r = 547.25
Triclinic,
a = 9.212 (4) Å
b = 9.370 (4) Å
c = 14.295 (5) Å
α = 85.30 (3)°
β = 84.83 (3)°
γ = 69.08 (3)°
V = 1146.2 (8) Å³
Z = 2
Mo Kα radiation
μ = 1.02 mm⁻¹
T = 100 K
0.34 × 0.16 × 0.12 mm

Data collection

Kuma KM-4 CCD diffractometer
Absorption correction: analytical (CrysAlis RED; Oxford Diffraction, 2010 ▶) T _min = 0.812, T _max = 0.908
12801 measured reflections
5113 independent reflections
4855 reflections with I > 2σ(I)
R _int = 0.023

Refinement

R[F ² > 2σ(F ²)] = 0.029
wR(F ²) = 0.082
S = 1.37
5113 reflections
319 parameters
H-atom parameters constrained
Δρ_max = 0.39 e Å⁻³
Δρ_min = −0.40 e Å⁻³

Data collection: CrysAlis CCD (Oxford Diffraction, 2010 ▶); cell refinement: CrysAlis RED (Oxford Diffraction, 2010 ▶); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536812003431/bt5799sup1.cif

e-68-0m227-sup1.cif^{(33.9KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812003431/bt5799Isup2.hkl

e-68-0m227-Isup2.hkl^{(245.3KB, hkl)}

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

Table 1. Selected geometric parameters (Å, °).

Pd—C11	2.003 (3)
Pd—N41	2.088 (3)
Pd—P	2.1667 (12)
Pd—Cl	2.3890 (12)

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P—Pd—Cl	94.52 (4)
P—Pd—C11	81.51 (10)
C11—Pd—N41	93.91 (12)
N41—Pd—Cl	89.88 (8)
C11—Pd—Cl	175.48 (8)
N41—Pd—P	173.55 (8)

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Table 2. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C14—H14⋯O3ⁱ	0.95	2.66	3.365 (4)	132
C15—H15⋯Clⁱ	0.95	2.80	3.720 (4)	162
C33—H33⋯Clⁱⁱ	0.95	2.88	3.541 (4)	128
C35—H35⋯Clⁱⁱⁱ	0.95	2.89	3.817 (4)	164
C44—H44⋯Cl^iv	0.95	2.78	3.651 (4)	154

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

Acknowledgments

This work was supported by European funds in the frame of the Human Capital Operational Programme through project No. POKL.04.01.01–00-054/10–00 ‘Development of the potential and educational offer of the University of Wrocław – the chance to enhance the competitiveness of the University’. The financial support is gratefully acknowledged.

supplementary crystallographic information

Comment

Carbon-carbon bond-forming catalytic reactions are very important fundamental processes in synthetic chemistry. Among them, the commonly recognized are the Suzuki-Miyaura reaction that leads to formation of biphenyl derivates (Miyaura et al., 1981) and the Sonogashira reaction, which produces phenylated alkines (Sonogashira et al., 1975). In this paper we report the crystallization of a palladacyclic triphenylphosphite complex with a 1,2-dimethylimidazole ligand, the title compound. This complex exhibited high catalytic activity in the Suzuki-Miyaura reaction in ethylene glycol and in the Sonogashira reaction in ionic liquids (Błaszczyk et al., 2011).

The molecular structure of the title compound reveals that the coordination environment of the Pd atom is a slightly distorted square-planar (Fig. 1). The angles between adjacent ligands deviate somewhat from the expected value of 90° (Table 1). However, the observed bond distances and angles are similar to the already reported for analogous complexes (Błaszczyk et al., 2011). In the title compound the metallated carbon is in the trans orientation to the Cl atom. As a result of the trans influence of the aryl group, the Pd—Cl bond length (Table 1) appears somewhat longer than expected for palladium complexes: 2.298–2.354Å (Orpen et al., 1989). The imidazole ring is oriented at 75.7° with respect to the coordination plane of palladium. The C21—C26 phenyl ring is disordered over two positions with site occupancy factors about 51 and 49%.

The structure is stabilized by a few weak hydrogen bonds of the C—H···O and C—H···Cl types (Desiraju & Steiner, 1999). Consequently, a three-dimensional network of such interactions is formed in the crystal. The shortest C—H···Cl distances observed in the title compound are similar to the values of the N—H···Cl hydrogen bonds identified for Cl bonded to a transition metal (Aullón et al., 1998).

Experimental

The title compound was prepared according to the previously reported procedure (Błaszczyk et al., 2011): 1,2-dimethylimidazole (0.128 g, 1,32 mmol) was added to the solution of [PdCl{P(OC₆H₄)(OC₆H₅)₂}]₂ (0.30 g, 0.33 mmol) in dichloromethane (4 ml). The starting dimeric palladyclic complex [PdCl{P(OC₆H₄)(OC₆H₅)₂}]₂ had been obtained according to published method (Albinati et al., 1990). The solution was stirred at room temperature for 1 h. The solvent was evaporated in vacuo and the white product was precipitated by addition of ethanol and recrystallized from a mixure of dichloromethane and ethanol. Yield: 0.35 g, 97%. Analysis calculated: C 50.48, H 4.05, N 5.12%; found: C 50.30, H 3.98, N 4.93%. ¹H NMR (CDCl₃): δ 8.27 (1H, t, J = 6.1 Hz; orthopalladated ring), 6.30–7.60 (m, Ph), 3.54 (3H, s, CH₃; major isomer), 3.45 (3H, s, CH₃; minor isomer), 2.29 (3H, s, CH₃; major isomer), 2.07 (3H, s, CH₃; minor isomer). ³¹P NMR (CDCl₃): δ 132.17 (major isomer), 124.70 (minor isomer).