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ISSN: 2056-9890

[(2,3,5,6-η)-Bi­cyclo­[2.2.1]hepta-2,5-diene]di­bromidopalladium(II)

aSchool of Applied Chemical Engineering, the Research Institute of Catalysis, Chonnam National University, Gwangju 500-757, Republic of Korea
*Correspondence e-mail: hakwang@chonnam.ac.kr

(Received 28 May 2009; accepted 30 May 2009; online 6 June 2009)

In the title complex, [PdBr2(C7H8)], the PdII ion lies in a distorted square-planar environment defined by the two Br atoms and the mid-points of the two π-coordinated double bonds of bicyclo­[2.2.1]hepta-2,5-diene. The complex is disposed about a crystallographic mirror plane parallel to the ac plane passing through the Pd, Br atoms and the centre of the diene ligand.

Related literature

For the preparation of [PdX2(nbd)] (X = Cl or Br; nbd = (norbornadiene), see: Alexander et al. (1960[Alexander, R. A., Baenziger, N. C., Carpenter, C. & Doyle, J. R. (1960). J. Am. Chem. Soc. 82, 535-538.]). For the crystal structure of [PdCl2(nbd)], see: Baenziger et al. (1965[Baenziger, N. C., Richards, G. F. & Doyle, J. R. (1965). Acta Cryst. 18, 924-926.]). For the gas electron diffraction structure of norbornadiene, see: Yokozeki & Kuchitsu (1971[Yokozeki, A. & Kuchitsu, K. (1971). Bull. Chem. Soc. Jpn, 44, 2356-2363.]).

[Scheme 1]

Experimental

Crystal data
  • [PdBr2(C7H8)]

  • Mr = 358.35

  • Orthorhombic, P n m a

  • a = 12.758 (2) Å

  • b = 7.4313 (11) Å

  • c = 9.0138 (14) Å

  • V = 854.6 (2) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 11.44 mm−1

  • T = 296 K

  • 0.22 × 0.20 × 0.15 mm

Data collection
  • Bruker SMART 1000 CCD diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2000[Bruker (2000). SADABS, SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.126, Tmax = 0.180

  • 5210 measured reflections

  • 944 independent reflections

  • 673 reflections with I > 2σ(I)

  • Rint = 0.042

Refinement
  • R[F2 > 2σ(F2)] = 0.026

  • wR(F2) = 0.071

  • S = 0.99

  • 944 reflections

  • 52 parameters

  • H-atom parameters constrained

  • Δρmax = 1.10 e Å−3

  • Δρmin = −1.79 e Å−3

Data collection: SMART (Bruker, 2000[Bruker (2000). SADABS, SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2000[Bruker (2000). SADABS, SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; 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: PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]); software used to prepare material for publication: SHELXL97.

Supporting information


Comment top

The title complex, [PdBr2(C7H8)], is isomorphous with the analogous Pd(II) complex [PdCl2(C7H8)] (Baenziger et al., 1965). In the complex, the central PdII ion is essentially in a square-planar environment defined by the two Br atoms and the two midpoints (M1, M2) of the π-coordinated double bonds of the bicyclo[2.2.1]hepta-2,5-diene (norbornadiene; nbd) ligand [M1 and M2 denote the midpoints of the olefinic bonds C1—C1a and C2—C2a, respectively; symmetry code: (a) x, 1/2 - y, z] (Fig. 1). The complex is disposed about a crystallographic mirror plane parallel to the ac plane passing through the Pd atom, the Br atoms and the centre of the ligand with the special positions (x, 1/4, z) (Fig. 2). The pairs of Pd—Br and Pd—C bond lengths are almost equal (Pd—Br: 2.4258 (11) and 2.4294 (10) Å; Pd—C: 2.165 (5) and 2.170 (5) Å). The nbd ligand coordinates symmetrically to the Pd atom, and displays a slight increase in the double-bond distances (1.389 (10) and 1.388 (10) Å) compared with the non-coordinating double bonds of nbd in the gas phase (1.343 (3) Å; Yokozeki & Kuchitsu, 1971).

Related literature top

For the preparation of [PdX2(nbd)] (X = Cl or Br), see: Alexander et al. (1960). For the crystal structure of [PdCl2(nbd)], see: Baenziger et al. (1965). For the gas electron diffraction structure of norbornadiene, see: Yokozeki & Kuchitsu (1971).

Experimental top

To a solution of (bicyclo[2.2.1]hepta-2,5-diene)dichloridopalladium(II) (0.200 g, 0.742 mmol) in EtOH (20 ml) was added NaBr (0.816 g, 7.931 mmol), and refluxed for 1 h. The formed precipitate was separated by filtration and washed with EtOH and water and dried under vacuum, to give an orange powder (0.053 g). Crystals suitable for X-ray analysis were obtained by slow evaporation from a CH3CN solution.

Refinement top

H atoms were positioned geometrically and allowed to ride on their respective parent atoms [C—H = 0.98 (CH) or 0.97 Å (CH2) and Uiso(H) = 1.2Ueq(C)].

Computing details top

Data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT (Bruker, 2000); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The structure of the title complex, with displacement ellipsoids drawn at the 40% probability level for non-H atoms [Symmetry code: (a) x, 1/2 - y, z].
[Figure 2] Fig. 2. View of the unit-cell contents of the title complex.
[(2,3,5,6-η)-Bicyclo[2.2.1]hepta-2,5-diene]dibromidopalladium(II) top
Crystal data top
[PdBr2(C7H8)]F(000) = 664
Mr = 358.35Dx = 2.785 Mg m3
Orthorhombic, PnmaMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2nCell parameters from 2031 reflections
a = 12.758 (2) Åθ = 2.7–27.9°
b = 7.4313 (11) ŵ = 11.44 mm1
c = 9.0138 (14) ÅT = 296 K
V = 854.6 (2) Å3Block, orange
Z = 40.22 × 0.20 × 0.15 mm
Data collection top
Bruker SMART 1000 CCD
diffractometer
944 independent reflections
Radiation source: fine-focus sealed tube673 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.042
ϕ and ω scansθmax = 26.4°, θmin = 2.8°
Absorption correction: multi-scan
(SADABS; Bruker, 2000)
h = 1415
Tmin = 0.126, Tmax = 0.180k = 89
5210 measured reflectionsl = 116
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)] = 0.026Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.071H-atom parameters constrained
S = 0.99 w = 1/[σ2(Fo2) + (0.0331P)2]
where P = (Fo2 + 2Fc2)/3
944 reflections(Δ/σ)max < 0.001
52 parametersΔρmax = 1.10 e Å3
0 restraintsΔρmin = 1.79 e Å3
Crystal data top
[PdBr2(C7H8)]V = 854.6 (2) Å3
Mr = 358.35Z = 4
Orthorhombic, PnmaMo Kα radiation
a = 12.758 (2) ŵ = 11.44 mm1
b = 7.4313 (11) ÅT = 296 K
c = 9.0138 (14) Å0.22 × 0.20 × 0.15 mm
Data collection top
Bruker SMART 1000 CCD
diffractometer
944 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2000)
673 reflections with I > 2σ(I)
Tmin = 0.126, Tmax = 0.180Rint = 0.042
5210 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0260 restraints
wR(F2) = 0.071H-atom parameters constrained
S = 0.99Δρmax = 1.10 e Å3
944 reflectionsΔρmin = 1.79 e Å3
52 parameters
Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s 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 > σ(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
Pd10.06852 (4)0.25000.92135 (7)0.0312 (2)
Br10.19165 (7)0.25001.12643 (11)0.0462 (3)
Br20.08564 (6)0.25001.07957 (11)0.0491 (3)
C10.1765 (4)0.1566 (7)0.7528 (6)0.0363 (14)
H10.23880.08440.77520.044*
C20.0067 (4)0.1566 (7)0.7196 (6)0.0380 (14)
H20.07090.08440.71920.046*
C30.0934 (4)0.0997 (8)0.6402 (7)0.0419 (15)
H30.09670.02410.60310.050*
C40.1048 (6)0.25000.5270 (11)0.052 (2)
H4A0.17270.25000.47860.063*
H4B0.04920.25000.45360.063*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Pd10.0263 (3)0.0349 (4)0.0325 (4)0.0000.0009 (3)0.000
Br10.0491 (5)0.0448 (5)0.0448 (6)0.0000.0147 (4)0.000
Br20.0430 (5)0.0488 (6)0.0556 (7)0.0000.0181 (4)0.000
C10.025 (2)0.046 (3)0.038 (4)0.007 (2)0.006 (2)0.005 (3)
C20.032 (3)0.048 (3)0.034 (3)0.006 (2)0.007 (3)0.002 (3)
C30.043 (3)0.040 (3)0.042 (4)0.003 (3)0.002 (3)0.013 (3)
C40.043 (5)0.073 (7)0.040 (6)0.0000.005 (4)0.000
Geometric parameters (Å, º) top
Pd1—C1i2.165 (5)C2—C2i1.388 (10)
Pd1—C12.165 (5)C2—C31.523 (7)
Pd1—C2i2.170 (5)C2—H20.9800
Pd1—C22.170 (5)C3—C41.520 (9)
Pd1—Br12.4258 (11)C3—H30.9800
Pd1—Br22.4294 (10)C4—C3i1.520 (9)
C1—C1i1.389 (10)C4—H4A0.9700
C1—C31.527 (7)C4—H4B0.9700
C1—H10.9800
C1i—Pd1—C137.4 (3)Pd1—C1—H1123.2
C1i—Pd1—C2i65.8 (2)C2i—C2—C3106.1 (3)
C1—Pd1—C2i78.2 (2)C2i—C2—Pd171.35 (14)
C1i—Pd1—C278.2 (2)C3—C2—Pd196.4 (3)
C1—Pd1—C265.8 (2)C2i—C2—H2123.2
C2i—Pd1—C237.3 (3)C3—C2—H2123.2
C1i—Pd1—Br197.05 (14)Pd1—C2—H2123.2
C1—Pd1—Br197.05 (14)C4—C3—C2101.0 (5)
C2i—Pd1—Br1157.65 (14)C4—C3—C1100.2 (5)
C2—Pd1—Br1157.65 (14)C2—C3—C1101.1 (4)
C1i—Pd1—Br2157.97 (13)C4—C3—H3117.2
C1—Pd1—Br2157.97 (13)C2—C3—H3117.2
C2i—Pd1—Br297.71 (14)C1—C3—H3117.2
C2—Pd1—Br297.71 (14)C3i—C4—C394.6 (7)
Br1—Pd1—Br294.41 (4)C3i—C4—H4A112.8
C1i—C1—C3106.1 (3)C3—C4—H4A112.8
C1i—C1—Pd171.29 (13)C3i—C4—H4B112.8
C3—C1—Pd196.5 (3)C3—C4—H4B112.8
C1i—C1—H1123.2H4A—C4—H4B110.3
C3—C1—H1123.2
C2i—Pd1—C1—C1i65.45 (15)C2i—Pd1—C2—C3104.9 (3)
C2—Pd1—C1—C1i102.59 (16)Br1—Pd1—C2—C340.3 (6)
Br2—Pd1—C1—C1i146.8 (4)Br2—Pd1—C2—C3162.5 (3)
C1i—Pd1—C1—C3104.8 (3)C2i—C2—C3—C433.3 (5)
C2i—Pd1—C1—C339.3 (3)Pd1—C2—C3—C4105.7 (4)
C2—Pd1—C1—C32.2 (3)C2i—C2—C3—C169.5 (4)
Br1—Pd1—C1—C3162.8 (3)Pd1—C2—C3—C12.9 (4)
Br2—Pd1—C1—C342.0 (6)C1i—C1—C3—C434.0 (4)
C1i—Pd1—C2—C2i65.40 (15)Pd1—C1—C3—C4106.4 (4)
C1—Pd1—C2—C2i102.69 (16)C1i—C1—C3—C269.5 (4)
Br1—Pd1—C2—C2i145.2 (4)Pd1—C1—C3—C22.9 (4)
C1i—Pd1—C2—C339.5 (3)C2—C3—C4—C3i51.1 (6)
C1—Pd1—C2—C32.2 (3)C1—C3—C4—C3i52.5 (6)
Symmetry code: (i) x, y+1/2, z.

Experimental details

Crystal data
Chemical formula[PdBr2(C7H8)]
Mr358.35
Crystal system, space groupOrthorhombic, Pnma
Temperature (K)296
a, b, c (Å)12.758 (2), 7.4313 (11), 9.0138 (14)
V3)854.6 (2)
Z4
Radiation typeMo Kα
µ (mm1)11.44
Crystal size (mm)0.22 × 0.20 × 0.15
Data collection
DiffractometerBruker SMART 1000 CCD
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 2000)
Tmin, Tmax0.126, 0.180
No. of measured, independent and
observed [I > 2σ(I)] reflections
5210, 944, 673
Rint0.042
(sin θ/λ)max1)0.625
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.026, 0.071, 0.99
No. of reflections944
No. of parameters52
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)1.10, 1.79

Computer programs: SMART (Bruker, 2000), SAINT (Bruker, 2000), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), PLATON (Spek, 2009).

 

Acknowledgements

This work was supported by a Korea Research Foundation Grant funded by the Korean Government (MOEHRD) (KRF-2007–412-J02001).

References

First citationAlexander, R. A., Baenziger, N. C., Carpenter, C. & Doyle, J. R. (1960). J. Am. Chem. Soc. 82, 535–538.  CrossRef CAS Web of Science Google Scholar
First citationBaenziger, N. C., Richards, G. F. & Doyle, J. R. (1965). Acta Cryst. 18, 924–926.  CSD CrossRef CAS IUCr Journals Web of Science Google Scholar
First citationBruker (2000). SADABS, SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSpek, A. L. (2009). Acta Cryst. D65, 148–155.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationYokozeki, A. & Kuchitsu, K. (1971). Bull. Chem. Soc. Jpn, 44, 2356–2363.  CrossRef CAS Web of Science Google Scholar

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ISSN: 2056-9890
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