Acta Cryst. (2009). E65, m727 [ doi:10.1107/S1600536809020583 ]
![[eta]](/logos/entities/eta_rmgif.gif)
)-Bicyclo[2.2.1]hepta-2,5-diene]dibromidopalladium(II)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 ![[pi]](/logos/entities/pi_rmgif.gif)
-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.
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.
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)].
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).
![[Figure 1]](./ez2172fig1thm.gif)
| 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]](./ez2172fig2thm.gif)
| Fig. 2. View of the unit-cell contents of the title complex. |
| [PdBr2(C7H8)] | F(000) = 664 |
| Mr = 358.35 | Dx = 2.785 Mg m−3 |
| Orthorhombic, Pnma | Mo Kα radiation, λ = 0.71073 Å |
| Hall symbol: -P 2ac 2n | Cell parameters from 2031 reflections |
| a = 12.758 (2) Å | θ = 2.7–27.9° |
| b = 7.4313 (11) Å | µ = 11.44 mm−1 |
| c = 9.0138 (14) Å | T = 296 K |
| V = 854.6 (2) Å3 | Block, orange |
| Z = 4 | 0.22 × 0.20 × 0.15 mm |
| Bruker SMART 1000 CCD diffractometer | 944 independent reflections |
| Radiation source: fine-focus sealed tube | 673 reflections with I > 2σ(I) |
| graphite | Rint = 0.042 |
| φ and ω scans | θmax = 26.4°, θmin = 2.8° |
| Absorption correction: multi-scan (SADABS; Bruker, 2000) | h = −14→15 |
| Tmin = 0.126, Tmax = 0.180 | k = −8→9 |
| 5210 measured reflections | l = −11→6 |
| Refinement on F2 | Primary atom site location: structure-invariant direct methods |
| Least-squares matrix: full | Secondary atom site location: difference Fourier map |
| R[F2 > 2σ(F2)] = 0.026 | Hydrogen site location: inferred from neighbouring sites |
| wR(F2) = 0.071 | H-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 parameters | Δρmax = 1.10 e Å−3 |
| 0 restraints | Δρmin = −1.79 e Å−3 |
| [PdBr2(C7H8)] | V = 854.6 (2) Å3 |
| Mr = 358.35 | Z = 4 |
| Orthorhombic, Pnma | Mo Kα radiation |
| a = 12.758 (2) Å | µ = 11.44 mm−1 |
| b = 7.4313 (11) Å | T = 296 K |
| c = 9.0138 (14) Å | 0.22 × 0.20 × 0.15 mm |
| 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 = 0.180 | Rint = 0.042 |
| 5210 measured reflections | θmax = 26.4° |
| R[F2 > 2σ(F2)] = 0.026 | H-atom parameters constrained |
| wR(F2) = 0.071 | Δρmax = 1.10 e Å−3 |
| S = 0.99 | Δρmin = −1.79 e Å−3 |
| 944 reflections | Absolute structure: ? |
| 52 parameters | Flack parameter: ? |
| 0 restraints | Rogers parameter: ? |
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. |
| x | y | z | Uiso*/Ueq | ||
| Pd1 | 0.06852 (4) | 0.2500 | 0.92135 (7) | 0.0312 (2) | |
| Br1 | 0.19165 (7) | 0.2500 | 1.12643 (11) | 0.0462 (3) | |
| Br2 | −0.08564 (6) | 0.2500 | 1.07957 (11) | 0.0491 (3) | |
| C1 | 0.1765 (4) | 0.1566 (7) | 0.7528 (6) | 0.0363 (14) | |
| H1 | 0.2388 | 0.0844 | 0.7752 | 0.044* | |
| C2 | −0.0067 (4) | 0.1566 (7) | 0.7196 (6) | 0.0380 (14) | |
| H2 | −0.0709 | 0.0844 | 0.7192 | 0.046* | |
| C3 | 0.0934 (4) | 0.0997 (8) | 0.6402 (7) | 0.0419 (15) | |
| H3 | 0.0967 | −0.0241 | 0.6031 | 0.050* | |
| C4 | 0.1048 (6) | 0.2500 | 0.5270 (11) | 0.052 (2) | |
| H4A | 0.1727 | 0.2500 | 0.4786 | 0.063* | |
| H4B | 0.0492 | 0.2500 | 0.4536 | 0.063* |
| U11 | U22 | U33 | U12 | U13 | U23 | |
| Pd1 | 0.0263 (3) | 0.0349 (4) | 0.0325 (4) | 0.000 | 0.0009 (3) | 0.000 |
| Br1 | 0.0491 (5) | 0.0448 (5) | 0.0448 (6) | 0.000 | −0.0147 (4) | 0.000 |
| Br2 | 0.0430 (5) | 0.0488 (6) | 0.0556 (7) | 0.000 | 0.0181 (4) | 0.000 |
| C1 | 0.025 (2) | 0.046 (3) | 0.038 (4) | 0.007 (2) | 0.006 (2) | −0.005 (3) |
| C2 | 0.032 (3) | 0.048 (3) | 0.034 (3) | −0.006 (2) | −0.007 (3) | −0.002 (3) |
| C3 | 0.043 (3) | 0.040 (3) | 0.042 (4) | 0.003 (3) | 0.002 (3) | −0.013 (3) |
| C4 | 0.043 (5) | 0.073 (7) | 0.040 (6) | 0.000 | 0.005 (4) | 0.000 |
| Pd1—C1i | 2.165 (5) | C2—C2i | 1.388 (10) |
| Pd1—C1 | 2.165 (5) | C2—C3 | 1.523 (7) |
| Pd1—C2i | 2.170 (5) | C2—H2 | 0.9800 |
| Pd1—C2 | 2.170 (5) | C3—C4 | 1.520 (9) |
| Pd1—Br1 | 2.4258 (11) | C3—H3 | 0.9800 |
| Pd1—Br2 | 2.4294 (10) | C4—C3i | 1.520 (9) |
| C1—C1i | 1.389 (10) | C4—H4A | 0.9700 |
| C1—C3 | 1.527 (7) | C4—H4B | 0.9700 |
| C1—H1 | 0.9800 | ||
| C1i—Pd1—C1 | 37.4 (3) | Pd1—C1—H1 | 123.2 |
| C1i—Pd1—C2i | 65.8 (2) | C2i—C2—C3 | 106.1 (3) |
| C1—Pd1—C2i | 78.2 (2) | C2i—C2—Pd1 | 71.35 (14) |
| C1i—Pd1—C2 | 78.2 (2) | C3—C2—Pd1 | 96.4 (3) |
| C1—Pd1—C2 | 65.8 (2) | C2i—C2—H2 | 123.2 |
| C2i—Pd1—C2 | 37.3 (3) | C3—C2—H2 | 123.2 |
| C1i—Pd1—Br1 | 97.05 (14) | Pd1—C2—H2 | 123.2 |
| C1—Pd1—Br1 | 97.05 (14) | C4—C3—C2 | 101.0 (5) |
| C2i—Pd1—Br1 | 157.65 (14) | C4—C3—C1 | 100.2 (5) |
| C2—Pd1—Br1 | 157.65 (14) | C2—C3—C1 | 101.1 (4) |
| C1i—Pd1—Br2 | 157.97 (13) | C4—C3—H3 | 117.2 |
| C1—Pd1—Br2 | 157.97 (13) | C2—C3—H3 | 117.2 |
| C2i—Pd1—Br2 | 97.71 (14) | C1—C3—H3 | 117.2 |
| C2—Pd1—Br2 | 97.71 (14) | C3i—C4—C3 | 94.6 (7) |
| Br1—Pd1—Br2 | 94.41 (4) | C3i—C4—H4A | 112.8 |
| C1i—C1—C3 | 106.1 (3) | C3—C4—H4A | 112.8 |
| C1i—C1—Pd1 | 71.29 (13) | C3i—C4—H4B | 112.8 |
| C3—C1—Pd1 | 96.5 (3) | C3—C4—H4B | 112.8 |
| C1i—C1—H1 | 123.2 | H4A—C4—H4B | 110.3 |
| C3—C1—H1 | 123.2 | ||
| C2i—Pd1—C1—C1i | 65.45 (15) | C2i—Pd1—C2—C3 | 104.9 (3) |
| C2—Pd1—C1—C1i | 102.59 (16) | Br1—Pd1—C2—C3 | −40.3 (6) |
| Br2—Pd1—C1—C1i | 146.8 (4) | Br2—Pd1—C2—C3 | −162.5 (3) |
| C1i—Pd1—C1—C3 | −104.8 (3) | C2i—C2—C3—C4 | −33.3 (5) |
| C2i—Pd1—C1—C3 | −39.3 (3) | Pd1—C2—C3—C4 | −105.7 (4) |
| C2—Pd1—C1—C3 | −2.2 (3) | C2i—C2—C3—C1 | 69.5 (4) |
| Br1—Pd1—C1—C3 | 162.8 (3) | Pd1—C2—C3—C1 | −2.9 (4) |
| Br2—Pd1—C1—C3 | 42.0 (6) | C1i—C1—C3—C4 | 34.0 (4) |
| C1i—Pd1—C2—C2i | −65.40 (15) | Pd1—C1—C3—C4 | 106.4 (4) |
| C1—Pd1—C2—C2i | −102.69 (16) | C1i—C1—C3—C2 | −69.5 (4) |
| Br1—Pd1—C2—C2i | −145.2 (4) | Pd1—C1—C3—C2 | 2.9 (4) |
| C1i—Pd1—C2—C3 | 39.5 (3) | C2—C3—C4—C3i | 51.1 (6) |
| C1—Pd1—C2—C3 | 2.2 (3) | C1—C3—C4—C3i | −52.5 (6) |
| Symmetry codes: (i) x, −y+1/2, z. |
This work was supported by a Korea Research Foundation Grant funded by the Korean Government (MOEHRD) (KRF-2007–412-J02001).
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Bruker (2000). SADABS, SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.
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Yokozeki, A. & Kuchitsu, K. (1971). Bull. Chem. Soc. Jpn, 44, 2356–2363.
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).