[1,2-Bis­(diisopropyl­phosphan­yl)ethane-κ2 P,P′]dichloridonickel(II)–9H-carbazole (1/2)

Farah Cañavera-Buelvas; Marcos Flores-Alamo; Juventino J García

doi:10.1107/S1600536811010555

. 2011 Mar 26;67(Pt 4):m501. doi: 10.1107/S1600536811010555

[1,2-Bis(diisopropylphosphanyl)ethane-κ² P,P′]dichloridonickel(II)–9H-carbazole (1/2)

Farah Cañavera-Buelvas ^a, Marcos Flores-Alamo ^a, Juventino J García ^a,^*

PMCID: PMC3100014 PMID: 21754008

Abstract

In the title compound, [NiCl₂(C₁₄H₃₂P₂)]·2C₁₂H₉N, the neutral [Ni(dppe)Cl₂] complex [dppe is 1,2-bis(diisopropylphosphanyl)ethane] consists of a tetracoordinated Ni²⁺ cation and has a crystallographic twofold axis passing through the metal atom and the mid-point of the CH₂—CH₂ bond of the dppe ligand. The metal atom shows slight tetrahedral distortion from an ideal square-planar coordination geometry, as reflected in the dihedral angle between NiCl₂ and NiP₂ planes of 15.32 (2)°. The 9H-carbazole ring system is essentially planar (r.m.s. deviation = 0.022 Å). In the crystal packing, there are two symmetry-related 9H-carbazole molecules between two adjacent Ni^II complexes, with an angle between the carbazole mean planes of ca 77°.

Related literature

For the use of nickel complexes of the type [Ni(dppe)Cl₂] as starting materials and precursors in metal-mediated and catalytic systems, respectively, see: Vicic & Jones (1997 ▶); Arévalo & García (2010 ▶). For details of tetrahedral distortion and motifs, see: Angulo et al. (2003 ▶); Dahlenburg & Kurth (2001 ▶); Etter et al. (1990 ▶).

Experimental

Crystal data

[NiCl₂(C₁₄H₃₂P₂)]·2C₁₂H₉N
M _r = 726.35
Monoclinic,
a = 22.5830 (5) Å
b = 8.4374 (2) Å
c = 18.9630 (5) Å
β = 101.544 (2)°
V = 3540.15 (15) Å³
Z = 4
Mo Kα radiation
μ = 0.82 mm⁻¹
T = 122 K
0.42 × 0.16 × 0.02 mm

Data collection

Oxford Diffraction Xcalibur Atlas Gemini diffractometer
Absorption correction: analytical [CrysAlis PRO (Oxford Diffraction, 2009 ▶); based on expressions derived by Clark & Reid (1995 ▶)] T _min = 0.851, T _max = 0.987
12792 measured reflections
3484 independent reflections
2908 reflections with I > 2σ(I)
R _int = 0.027

Refinement

R[F ² > 2σ(F ²)] = 0.026
wR(F ²) = 0.065
S = 1.05
3484 reflections
211 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.62 e Å⁻³
Δρ_min = −0.26 e Å⁻³

Data collection: CrysAlis CCD (Oxford Diffraction, 2009 ▶); cell refinement: CrysAlis RED (Oxford Diffraction, 2009 ▶); 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 for Windows (Farrugia, 1997 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811010555/bh2344sup1.cif

e-67-0m501-sup1.cif^{(19.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811010555/bh2344Isup2.hkl

e-67-0m501-Isup2.hkl^{(167.5KB, hkl)}

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

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

Ni1—Cl1	2.2221 (4)
Ni1—P1	2.1581 (5)

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P1ⁱ—Ni1—P1	88.61 (3)
P1ⁱ—Ni1—Cl1ⁱ	168.757 (16)
P1ⁱ—Ni1—Cl1	89.797 (16)
Cl1ⁱ—Ni1—Cl1	93.87 (2)

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Symmetry code: (i) Inline graphic .

Acknowledgments

We thank PAPIIT-DGAPA-UNAM (IN-201010) and CONACYT (080606) for their financial support of this work and DGAPA-UNAM for a postdoctoral grant to FCB. We also thank Dr A. Arévalo for technical assistance.

supplementary crystallographic information

Comment

The nickel complexes of the type [Ni(dppe)Cl₂] are useful starting materials for the preparation of catalysts and catalytic precursors, for an interesting series of active catalyst in a wide variety of stoichiometric (Vicic & Jones, 1997) and catalytic systems (Arévalo & García, 2010). The synthesis of the current complex [Ni (dppe)Cl₂](carbazole)₂ (see Scheme) can be envisaged as the preparation of a model compound relevant to hydrodenitrogenation and N—H activation process.

In the asymmetric unit, the tetracoordinated [Ni(dppe)Cl₂] complex has a 2-fold axis passing through the metal and the centre of the methylene—methylene bond (Fig. 1). The metal center shows slight tetrahedral distortion from ideal square-planar coordination geometry, with the angle between the normals to the planes defined by the two cis-Cl–Ni–Cl and cis-P–Ni–P fragments [15.32 (2)°] being larger than the limiting value of 0° for square-planar coordination. Additionally, the metal ion is situated 0.1144 (1) Å above the Cl1/P1/Cl1ⁱ/P1ⁱ plane [symmetry code: (i) -x, y, 1/2 - z]. These deviations from planarity, which can safely be attributed to some steric congestion by intermolecular contacts between the metallic complex and the 9H-carbazole molecules (Fig. 2), are somewhat larger than the distortion from ideal square-planar coordination geometry observed for related [Ni(dcpe)Cl₂] (Angulo et al., 2003) and [(1S,2S)-C₅H₈{P(C₆H₁₁)₂}₂NiCl₂] (Dahlenburg & Kurth, 2001) complexes, where the NiCl₂/NiP₂ dihedral angles are 3.96 and 5.37°, respectively. The Ni–P bond lengths in the title compound are equal, by symmetry. Probably as a consequence of the steric bulk of the 9H-carbazole molecules, the Ni–Cl distance, 2.2221 (4) Å, tends to be slightly longer than those in the analogues nickel complexes.

In the crystal packing, there are two 9H-carbazole molecules between two adjacent nickel complexes, with an angle between the carbazole mean planes of ca. 77°. There are two types of intermolecular contacts: one of the van der Waals type N—H···Cl [2.65 (2) Å] is formed from N1 donor atom of the 9H-carbazole to Cl1 chloride atom acceptor of the metallic complex; and other of the type C—H···N [2.645 (1) Å] involving C19 in the dppe ligand and N1 in 9H-carbazole. These van der Waals interactions lead to infinite ribbons based on R¹₂(5) motifs (Etter et al., 1990), as illustrated in Fig. 2.

Experimental

A THF solution of [Ni(dppe)H]₂ (Vicic & Jones, 1997) (0.100 g, 0.15 mmol) was added with 9H-carbazole (0. 261 g, 1.56 mmol) and heated to 80 °C for 10 h. After this time, the solution changed from wine red color to brown. The solvent was eliminated under reduced pressure and the resulting solid dissolved in dichloromethane (DCM). Slow evaporation at room temperature of DCM afforded crystals suitable for X-ray diffraction. NMR: ³¹P{¹H} (acetone-d₆,121.32 MHz, 25 °C): d 57.2. NMR ¹H (acetone-d₆, 300 MHz, 25 °C): d 8.13 (d, J_H—H=7.8, 1H), d 7.54 (d, J_H—H=7.8, 1H), d 7.39 (dd, J_H—H=7.8, J_H—H=7.2, 1H), d 7.18 (dd, J_H—H=7.2, J_H—H=7.8, 1H), d 2.5 (m, CH, 2H), d 1.7 (m, CH₂, 2H), d 1.35 (m, CH₃, 12H). Elemental analysis (calc.): C 62.9 (62.83), H 6.90 (6.93), N 3.82% (3.85%).