metal-organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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ISSN: 2056-9890

Bis[μ-2-(pyridin-2-yl)ethano­lato]bis­­[bromidocopper(II)]

aNational Single Crystal X-ray Diffraction Facility, IIT Bombay, Powai, Mumbai 400 076, India, and bDepartment of Natural Sciences, Coppin State University, 2500 West North Avenue, Baltimore, Maryland 21216, USA
*Correspondence e-mail: xray@chem.iitb.ac.in

(Received 25 September 2011; accepted 20 October 2011; online 29 October 2011)

The title compound, [Cu2Br2(C7H8NO)2], was synthesized by reaction of CuBr2 with 2-(pyridin-2-yl)ethanol (hep-H) in methanol. The asymmetric unit consists of one hep ligand and a CuBr unit. The Cu2+ ion is thereby coordinated by the N atom and the deprotonated hydroxy O atom in a distorted square-planar geometry that is completed by another O atom. The latter acts as bridging ligand towards the second, symmetry-equivalent, Cu atom, thus generating a centrosymmetric dimeric unit, with the inversion centre halfway between the Cu atoms. These units are linked via C—H⋯Br and C—H⋯O hydrogen bonds, leading to the formation of a hydrogen-bonded one-dimensional-polymeric chain along a..

Related literature

For similar dinuclear copper complexes see Lah et al. (2006[Lah, N., Leban, I. & Clérac, R. (2006). Eur. J. Inorg. Chem. pp. 4888-4894.]); Shaikh et al. (2010[Shaikh, M. M., Srivastava, A. K., Mathur, P. & Lahiri, G. K. (2010). Dalton Trans. 39, 1447-1449.]).

[Scheme 1]

Experimental

Crystal data
  • [Cu2Br2(C7H8NO)2]

  • Mr = 531.19

  • Triclinic, [P \overline 1]

  • a = 4.2066 (2) Å

  • b = 8.4338 (3) Å

  • c = 11.5113 (6) Å

  • α = 91.122 (4)°

  • β = 90.195 (3)°

  • γ = 97.033 (1)°

  • V = 405.24 (3) Å3

  • Z = 1

  • Mo Kα radiation

  • μ = 7.56 mm−1

  • T = 150 K

  • 0.28 × 0.21 × 0.17 mm

Data collection
  • Oxford Diffraction Xcalibur-S diffractometer

  • Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2009[Oxford Diffraction (2009). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Yarnton, Oxfordshire, England.])Tmin = 0.226, Tmax = 0.360

  • 3453 measured reflections

  • 1388 independent reflections

  • 1298 reflections with I > 2σ(I)

  • Rint = 0.026

Refinement
  • R[F2 > 2σ(F2)] = 0.031

  • wR(F2) = 0.087

  • S = 1.05

  • 1388 reflections

  • 100 parameters

  • H-atom parameters constrained

  • Δρmax = 0.84 e Å−3

  • Δρmin = −0.74 e Å−3

Table 1
Selected geometric parameters (Å, °)

Cu1—O1i 1.910 (3)
Cu1—O1 1.943 (3)
Cu1—N1 1.977 (3)
Cu1—Br1 2.3670 (6)
Cu1—Cu1i 3.0294 (9)
O1i—Cu1—O1 76.32 (12)
Cu1i—O1—Cu1 103.68 (12)
Symmetry code: (i) -x+2, -y+2, -z+2.

Table 2
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
C1—H1⋯Br1ii 0.95 3.00 3.716 (4) 134
C6—H6A⋯O1iii 0.99 2.64 3.545 (5) 153
Symmetry codes: (ii) x+1, y, z; (iii) x-1, y, z.

Data collection: CrysAlis CCD (Oxford Diffraction, 2009[Oxford Diffraction (2009). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Yarnton, Oxfordshire, England.]); cell refinement: CrysAlis CCD; data reduction: CrysAlis RED (Oxford Diffraction, 2009[Oxford Diffraction (2009). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Yarnton, Oxfordshire, England.]); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: DIAMOND (Brandenburg, 1999[Brandenburg, K. (1999). DIAMOND. Crystal Impact GbR, Bonn, Germany.]); software used to prepare material for publication: publCIF (Westrip, 2010[Westrip, S. P. (2010). J. Appl. Cryst. 43, 920-925. ]).

Supporting information


Comment top

Dinuclear Cu(II) complexes have often been used as models to study the magnetic-exchange interactions and as building blocks for the construction of polynuclear compounds with interesting magnetic properties (Lah et al. 2006). The alkoxo bridged dinuclear Cu(II) complexes consists of two copper atoms bridged by two alkoxido oxygen atoms from alkoxypyridine-type ligands have drawn considerable interest in solid state transformations (Shaikh et al. 2010).

The dimeric title compound (Fig.1) features a dinuclear complex with site symmetry –1. The Cu (II) ions are linked via the two µ2-alcoholic oxygen atoms, yielding a four-membered planar ring Cu2O2. One pyridine nitrogen atom of hep and the bromide ligands complete the coordination environment, yielding a distorted square-planar geometry. The Cu ions are separated by 3.0294 (9) Å. The µ-O bridge is slightly asymmetric with Cu—O distances of 1.910 (3) and 1.943 (3) Å and Cu—O—Cu angle of 103.68°. (Table 1). These bond-distances and angles are in agreement with the reported dimeric molecules by Lah et al. (2006) and Shaikh et al. (2010).

Moreover, each dimeric unit is further extended through C—H···Br and C—H···O hydrogen bondings (Table 2) with the neighboring dimeric unit forming a one-dimensional-polymeric chains along a-axis (Fig. 2).

Related literature top

For similar dinuclear copper complexes see Lah et al. (2006); Shaikh et al. (2010).

Experimental top

A solution of hep-H (123 mg, 1.0 mmol) in 30 ml methanol was added to a 10 ml methanolic solution of CuBr2 (223 mg, 1.0 mmol) and the resultant solution was stirred for 2 h at room temperature. The solution was then passed through filter paper (Whatman filter paper, 70 mm) in order to remove any unreacted materials. The filtrate was allowed to stand at room temperature for crystallization. On slow evaporation light blue single crystals of [Cu(µ-hep)Br]2 were obtained after 10 days. M.P.:488–490 K. Yield: 82%. Anal. Calcd for C14H16Br2Cu2N2O2 (Mr = 531.19): C,31.66; H, 3.04; N, 5.27. Found: C,31.30; H,3.11; N, 5.67.

Refinement top

The hydrogen atoms were placed geometrically and treated as riding on their parent atoms, with C—H 0.95 (pyridyl), C—H 0.99 (methylene) Å [Uiso(H) = 1.2Ueq(C)].

Computing details top

Data collection: CrysAlis PRO-CCD (Oxford Diffraction, 2009); cell refinement: CrysAlis PRO-CCD (Oxford Diffraction, 2009); data reduction: CrysAlis PRO-RED (Oxford Diffraction, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 1999); software used to prepare material for publication: publCIF (Westrip, 2010).

Figures top
[Figure 1] Fig. 1. View of the molecular structure of the title compound with displacement ellipsoids drawn at the 50% probability level. Symmetry-related moiety generated by i: –x, –y, –z.
[Figure 2] Fig. 2. A tilted perspective view of hydrogen bonded one-dimensional-polymeric chain along a-axis. Hydrogen bonds as dashed lines.
Bis[µ-2-(pyridin-2-yl)ethanolato]bis[bromidocopper(II)] top
Crystal data top
[Cu2Br2(C7H8NO)2]Z = 1
Mr = 531.19F(000) = 258
Triclinic, P1Dx = 2.177 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 4.2066 (2) ÅCell parameters from 3586 reflections
b = 8.4338 (3) Åθ = 3.5–30.0°
c = 11.5113 (6) ŵ = 7.56 mm1
α = 91.122 (4)°T = 150 K
β = 90.195 (3)°Block, blue
γ = 97.033 (1)°0.28 × 0.21 × 0.17 mm
V = 405.24 (3) Å3
Data collection top
Oxford Diffraction Xcalibur-S
diffractometer
1388 independent reflections
Radiation source: Enhance (Mo) X-ray Source1298 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.026
Detector resolution: 15.9948 pixels mm-1θmax = 25.0°, θmin = 3.5°
ω/q scansh = 54
Absorption correction: multi-scan
(CrysAlis PRO-RED; Oxford Diffraction, 2009)
k = 99
Tmin = 0.226, Tmax = 0.360l = 1313
3453 measured reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.031Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.087H-atom parameters constrained
S = 1.05 w = 1/[σ2(Fo2) + (0.0549P)2 + 0.5089P]
where P = (Fo2 + 2Fc2)/3
1388 reflections(Δ/σ)max = 0.001
100 parametersΔρmax = 0.84 e Å3
0 restraintsΔρmin = 0.74 e Å3
Crystal data top
[Cu2Br2(C7H8NO)2]γ = 97.033 (1)°
Mr = 531.19V = 405.24 (3) Å3
Triclinic, P1Z = 1
a = 4.2066 (2) ÅMo Kα radiation
b = 8.4338 (3) ŵ = 7.56 mm1
c = 11.5113 (6) ÅT = 150 K
α = 91.122 (4)°0.28 × 0.21 × 0.17 mm
β = 90.195 (3)°
Data collection top
Oxford Diffraction Xcalibur-S
diffractometer
1388 independent reflections
Absorption correction: multi-scan
(CrysAlis PRO-RED; Oxford Diffraction, 2009)
1298 reflections with I > 2σ(I)
Tmin = 0.226, Tmax = 0.360Rint = 0.026
3453 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0310 restraints
wR(F2) = 0.087H-atom parameters constrained
S = 1.05Δρmax = 0.84 e Å3
1388 reflectionsΔρmin = 0.74 e Å3
100 parameters
Special details top

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 (Å2) top
xyzUiso*/Ueq
Cu10.91306 (11)0.96968 (5)0.87303 (4)0.01736 (18)
Br10.60658 (9)0.76112 (4)0.76674 (3)0.02191 (18)
O11.0535 (7)1.1399 (3)0.9846 (2)0.0219 (6)
N11.0035 (8)1.1189 (4)0.7436 (3)0.0174 (7)
C11.1498 (10)1.0720 (5)0.6475 (4)0.0220 (9)
H11.18730.96350.63960.026*
C21.2475 (10)1.1759 (5)0.5598 (4)0.0254 (9)
H21.34951.13980.49250.030*
C31.1933 (10)1.3341 (5)0.5722 (4)0.0266 (10)
H31.25751.40820.51310.032*
C41.0444 (10)1.3833 (5)0.6716 (4)0.0226 (9)
H41.00821.49170.68170.027*
C50.9486 (9)1.2720 (5)0.7564 (3)0.0186 (8)
C60.7862 (9)1.3159 (5)0.8657 (4)0.0197 (8)
H6A0.58111.24560.87290.024*
H6B0.73651.42730.86050.024*
C70.9894 (10)1.3012 (4)0.9745 (3)0.0195 (8)
H7A1.19341.37280.96910.023*
H7B0.87371.33351.04410.023*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cu10.0243 (3)0.0158 (3)0.0116 (3)0.0008 (2)0.0009 (2)0.0016 (2)
Br10.0253 (3)0.0211 (3)0.0183 (3)0.00140 (17)0.00193 (18)0.00043 (17)
O10.0347 (17)0.0151 (14)0.0161 (15)0.0033 (12)0.0002 (12)0.0032 (11)
N10.0201 (17)0.0206 (17)0.0117 (17)0.0031 (13)0.0019 (13)0.0001 (13)
C10.025 (2)0.024 (2)0.018 (2)0.0060 (16)0.0004 (17)0.0012 (17)
C20.025 (2)0.035 (2)0.016 (2)0.0017 (18)0.0049 (17)0.0003 (18)
C30.028 (2)0.029 (2)0.022 (2)0.0008 (18)0.0017 (18)0.0086 (18)
C40.027 (2)0.019 (2)0.021 (2)0.0008 (16)0.0011 (17)0.0030 (16)
C50.0153 (19)0.023 (2)0.018 (2)0.0019 (15)0.0031 (15)0.0012 (16)
C60.020 (2)0.0186 (19)0.021 (2)0.0043 (16)0.0010 (16)0.0007 (16)
C70.023 (2)0.0172 (19)0.018 (2)0.0034 (15)0.0048 (16)0.0000 (16)
Geometric parameters (Å, º) top
Cu1—O1i1.910 (3)C2—H20.9500
Cu1—O11.943 (3)C3—C41.387 (6)
Cu1—N11.977 (3)C3—H30.9500
Cu1—Br12.3670 (6)C4—C51.394 (6)
Cu1—Cu1i3.0294 (9)C4—H40.9500
O1—C71.426 (4)C5—C61.496 (6)
O1—Cu1i1.910 (3)C6—C71.529 (6)
N1—C51.344 (5)C6—H6A0.9900
N1—C11.344 (5)C6—H6B0.9900
C1—C21.380 (6)C7—H7A0.9900
C1—H10.9500C7—H7B0.9900
C2—C31.385 (6)
O1i—Cu1—O176.32 (12)C2—C3—C4119.4 (4)
O1i—Cu1—N1162.34 (14)C2—C3—H3120.3
O1—Cu1—N190.44 (12)C4—C3—H3120.3
O1i—Cu1—Br198.08 (8)C3—C4—C5119.3 (4)
O1—Cu1—Br1163.87 (9)C3—C4—H4120.4
N1—Cu1—Br197.69 (10)C5—C4—H4120.4
O1i—Cu1—Cu1i38.54 (8)N1—C5—C4120.8 (4)
O1—Cu1—Cu1i37.78 (8)N1—C5—C6116.9 (3)
N1—Cu1—Cu1i127.28 (10)C4—C5—C6122.4 (4)
Br1—Cu1—Cu1i134.80 (3)C5—C6—C7112.9 (3)
C7—O1—Cu1i125.6 (2)C5—C6—H6A109.0
C7—O1—Cu1124.4 (2)C7—C6—H6A109.0
Cu1i—O1—Cu1103.68 (12)C5—C6—H6B109.0
C5—N1—C1119.7 (3)C7—C6—H6B109.0
C5—N1—Cu1119.9 (3)H6A—C6—H6B107.8
C1—N1—Cu1120.0 (3)O1—C7—C6109.4 (3)
N1—C1—C2122.3 (4)O1—C7—H7A109.8
N1—C1—H1118.9C6—C7—H7A109.8
C2—C1—H1118.9O1—C7—H7B109.8
C1—C2—C3118.5 (4)C6—C7—H7B109.8
C1—C2—H2120.8H7A—C7—H7B108.2
C3—C2—H2120.8
O1i—Cu1—O1—C7153.1 (4)Cu1—N1—C1—C2173.3 (3)
N1—Cu1—O1—C738.7 (3)N1—C1—C2—C30.3 (6)
Br1—Cu1—O1—C781.8 (4)C1—C2—C3—C40.2 (6)
Cu1i—Cu1—O1—C7153.1 (4)C2—C3—C4—C50.8 (6)
O1i—Cu1—O1—Cu1i0.0C1—N1—C5—C40.6 (6)
N1—Cu1—O1—Cu1i168.20 (15)Cu1—N1—C5—C4172.6 (3)
Br1—Cu1—O1—Cu1i71.3 (3)C1—N1—C5—C6179.7 (4)
O1i—Cu1—N1—C577.1 (5)Cu1—N1—C5—C66.5 (5)
O1—Cu1—N1—C536.2 (3)C3—C4—C5—N11.1 (6)
Br1—Cu1—N1—C5129.8 (3)C3—C4—C5—C6179.9 (4)
Cu1i—Cu1—N1—C545.2 (3)N1—C5—C6—C765.4 (5)
O1i—Cu1—N1—C196.1 (5)C4—C5—C6—C7113.7 (4)
O1—Cu1—N1—C1137.0 (3)Cu1i—O1—C7—C6145.3 (3)
Br1—Cu1—N1—C156.9 (3)Cu1—O1—C7—C61.9 (4)
Cu1i—Cu1—N1—C1128.0 (3)C5—C6—C7—O160.6 (4)
C5—N1—C1—C20.1 (6)
Symmetry code: (i) x+2, y+2, z+2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C1—H1···Br1ii0.953.003.716 (4)134
C6—H6A···O1iii0.992.643.545 (5)153
Symmetry codes: (ii) x+1, y, z; (iii) x1, y, z.

Experimental details

Crystal data
Chemical formula[Cu2Br2(C7H8NO)2]
Mr531.19
Crystal system, space groupTriclinic, P1
Temperature (K)150
a, b, c (Å)4.2066 (2), 8.4338 (3), 11.5113 (6)
α, β, γ (°)91.122 (4), 90.195 (3), 97.033 (1)
V3)405.24 (3)
Z1
Radiation typeMo Kα
µ (mm1)7.56
Crystal size (mm)0.28 × 0.21 × 0.17
Data collection
DiffractometerOxford Diffraction Xcalibur-S
diffractometer
Absorption correctionMulti-scan
(CrysAlis PRO-RED; Oxford Diffraction, 2009)
Tmin, Tmax0.226, 0.360
No. of measured, independent and
observed [I > 2σ(I)] reflections
3453, 1388, 1298
Rint0.026
(sin θ/λ)max1)0.595
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.031, 0.087, 1.05
No. of reflections1388
No. of parameters100
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.84, 0.74

Computer programs: CrysAlis PRO-CCD (Oxford Diffraction, 2009), CrysAlis PRO-RED (Oxford Diffraction, 2009), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg, 1999), publCIF (Westrip, 2010).

Selected geometric parameters (Å, º) top
Cu1—O1i1.910 (3)Cu1—N11.977 (3)
Cu1—O11.943 (3)Cu1—Cu1i3.0294 (9)
O1i—Cu1—O176.32 (12)Cu1i—O1—Cu1103.68 (12)
Symmetry code: (i) x+2, y+2, z+2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C1—H1···Br1ii0.953.003.716 (4)133.5
C6—H6A···O1iii0.992.643.545 (5)152.5
Symmetry codes: (ii) x+1, y, z; (iii) x1, y, z.
 

Acknowledgements

Financial support received from the Department of Science and Technology (New Delhi, India) is gratefully acknowledged. We also gratefully acknowledge Professor Pradeep Mathur, National Single Crystal X-ray Diffraction Facility, IIT Bombay, and Professor Goutam K. Lahiri, Chemistry Department, IIT Bombay, for their kind support for this work.

References

First citationBrandenburg, K. (1999). DIAMOND. Crystal Impact GbR, Bonn, Germany.  Google Scholar
First citationLah, N., Leban, I. & Clérac, R. (2006). Eur. J. Inorg. Chem. pp. 4888–4894.  Web of Science CSD CrossRef Google Scholar
First citationOxford Diffraction (2009). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Yarnton, Oxfordshire, England.  Google Scholar
First citationShaikh, M. M., Srivastava, A. K., Mathur, P. & Lahiri, G. K. (2010). Dalton Trans. 39, 1447–1449.  Web of Science PubMed Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationWestrip, S. P. (2010). J. Appl. Cryst. 43, 920–925.   Web of Science CrossRef CAS IUCr Journals Google Scholar

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