Tris[μ-1,2-bis­(diphenyl­phosphino)­ethane]-1:2κ2 P:P′;1:3κ2 P:P′;2:3κ2 P:P′-di-μ-bromido-1:2κ4 Br:Br-bromido-3κBr-tricopper(I) acetone hemisolvate

Wen-Juan Shi

doi:10.1107/S1600536808032789

. 2008 Oct 15;64(Pt 11):m1411. doi: 10.1107/S1600536808032789

Tris[μ-1,2-bis(diphenylphosphino)ethane]-1:2κ² P:P′;1:3κ² P:P′;2:3κ² P:P′-di-μ-bromido-1:2κ⁴ Br:Br-bromido-3κBr-tricopper(I) acetone hemisolvate

Wen-Juan Shi ^a,^*

PMCID: PMC2959548 PMID: 21580860

Abstract

In the crystal structure of the title compound, [Cu₃Br₃(C₂₆H₂₄P₂)₃]·0.5CH₃COCH₃, two of the Cu centers are bridged by two bromide anions forming a Cu(μ-Br)₂Cu core, which is further bridged by a 1,2-bis(diphenylphosphino)ethane (dppe) ligand. The third Cu center is terminally bound to another bromide ligand and is connected to the other two Cu atoms by bridging dppe ligands, forming a triangular cluster unit. The acetone solvent molecule exhibits twofold disorder about an inversion centre at ( Inline graphic , 1, 0). The crystal structure is stabilized by intermolecular C—H⋯Br hydrogen bonds.

Related literature

For related structures, see: Albano et al. (1972 ▶); Comba et al. (1999 ▶); Darensbourg et al. (1990 ▶); Effendy et al. (2006 ▶); Eller et al. (1977 ▶); Leoni et al. (1983 ▶); Mohr et al. (1991 ▶); Nicola et al. (2006 ▶).

Experimental

Crystal data

[Cu₃Br₃(C₂₆H₂₄P₂)₃]·0.5C₃H₆O
M _r = 1654.56
Monoclinic,
a = 18.6878 (10) Å
b = 17.1080 (9) Å
c = 25.2742 (13) Å
β = 109.924 (1)°
V = 7596.8 (7) Å³
Z = 4
Mo Kα radiation
μ = 2.58 mm⁻¹
T = 295 (2) K
0.22 × 0.20 × 0.18 mm

Data collection

Bruker SMART APEX area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.569, T _max = 0.625
38020 measured reflections
13376 independent reflections
8616 reflections with I > 2σ(I)
R _int = 0.050

Refinement

R[F ² > 2σ(F ²)] = 0.051
wR(F ²) = 0.140
S = 1.03
13376 reflections
715 parameters
29 restraints
H-atom parameters constrained
Δρ_max = 0.69 e Å⁻³
Δρ_min = −0.57 e Å⁻³

Data collection: SMART (Bruker, 2002 ▶); cell refinement: SAINT (Bruker, 2002 ▶); 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/S1600536808032789/sj2547sup1.cif

e-64-m1411-sup1.cif^{(49.3KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808032789/sj2547Isup2.hkl

e-64-m1411-Isup2.hkl^{(653.9KB, 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
C24—H24⋯Br1ⁱ	0.93	2.92	3.560 (3)	127
C65—H65A⋯Br1	0.97	2.85	3.576 (5)	132
C40—H40A⋯Br2	0.97	2.86	3.675 (5)	142

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Symmetry code: (i) Inline graphic .

Acknowledgments

The author thanks Jiangxi Science and Technology Normal University for supporting this study.

supplementary crystallographic information

Comment

Copper(I) halides react with bidentate phosphine ligands dppe [dppe is 1,2-bis(diphenylphosphino)ethane, C₂₆H₂₄P₂] to give a series with the compounds of general formula [Cu₂X₂(dppe)₃.solvate] (X is a halide anion) (Albano et al., 1972; Comba et al., 1999; Darensbourg et al., 1990; Effendy et al., 2006; Eller et al., 1977; Leoni et al., 1983; Mohr et al., 1991; Nicola et al., 2006). In these compounds Cu centers are bridged by a dppe ligand and each metal center carries one chelating dppe unit, with the fourth coordination site available for the Br^- anions. We now report the crystal structure of a triangular cluster (I), Fig 1, obtained by reaction of CuBr with dppe ligand in acetone as solvent.

The asymmetric unit of the structure consists of a trinuclear molecule Cu₃Br₃(dppe)₃ and half an acetone solvate molecule. In the molecule Cu₃ Br₃(dppe)₃, two copper(I) centers are bridged by the bromide ligands forming a Cu(µ-Br)₂Cu core, while the third copper(I) is terminally bonded to another bromide ligand. In the dinuclear Cu(µ-Br)₂Cu core, the Cu(1)···Cu(2) separation is 3.169 (2) Å, while Cu(1)···Cu(3) and Cu(2)···Cu(3) separations are 6.606 (2)Å and 6.537 (1) Å, respectively. The Cu₂Br₂ core does not lie in a plane but is bent with a dihedral angle of 27.4 (1) ° between the planes formed by Cu(1), Br(1), Cu(2), and Cu(1), Br(2), Cu2. Each copper cation binds to two bridging dppe ligands forming a triangular tri-copper cluster system. It is interesting that Cu centers have two different coordination environments in this compound, that is CuBr₂P₂ in a distorted tetrahedral geometry and CuBrP₂ in a slightly distorted trigonal planar geometry. In the tetrahedral CuBr₂P₂ core, the largest deviation from the ideal geometry is reflected in the P(1)—Cu(1)—P(3) [126.48 (5) °] and P(2)—Cu(2)—P(5) [126.48 (5) °] angles. These values are markedly higher than the normal tetrahedral value of 109.4 °.

The crystal structure is stabilized by intermolecular C—H···Br hydrogen bonds between the Br(1)^- anions and –CH groups from phenyl rings, forming a one-dimensional supramolecular array (Fig. 2).

Experimental

A solution of 1,2-bis(diphenylphosphino)ethane (0.0181 g, 0.05 mmol) was added to a stirred suspension of CuBr (0.0079 g, 0.05 mmol) in acetone (7 ml) and the mixture was stirred and moderately heated. After the formation of a completely clear solution, 5-methoxy-2-benzimidazolethiol (0.0095 g, 0.05 mmol) was added slowly and the stirring was continued for half an hour. The resulting solution was filtered off and stand at room temperature. Colorless crystals were formed after several days. Yield: 7 mg (18%).