Acta Cryst. (2007). E63, m3075 [ doi:10.1107/S1600536807058321 ]
![[kappa]](/logos/entities/kappa_rmgif.gif)
S)platinum(IV)The octahedral molecule of the title compound, [PtBr4(C2H6S)2], lies on an inversion centre [Pt-Br = 2.4654 (4) and 2.4761 (4) Å; Pt-S = 2.3624 (9) Å]. A similar set of bond distances is predicted by density functional theory.
The title compound was formed during an attempted synthesis of trans-[PtBr2(dms)2]. [K2PtCl4] (1.00 g, 2.41 mmol) was dissolved in water (50 ml). To this 5 equivalents of LiBr (g, mmol) was added. The solution was stirred for 30 min and an excess of dimethyl sulfide (4.5 ml, 60 mmol) was added and left to stir. After 3 h the complex was filtered off, washed with water and left to dry. Recrystallization from CH2Cl2 gave red cuboids.
DFT calculations were performed at the B3LYP level with the LANL2DZ basis set for platinum and the 6–311 G(d) basis set for bromine, sulfur, carbon and hydrogen atoms, using the Gaussian03 software package. Minima were verified via frequency analysis of the stationary point.
The methyl protons were placed in geometrically idealized positions and constrained to ride on their parent atoms with Uiso(H) = 1.5, with torsion angles refined from the electron density.
The final difference Fourier map had a large peak near Pt1.
Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT-Plus (Bruker, 2004); data reduction: SAINT-Plus (Bruker, 2004); program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: DIAMOND (Brandenburg & Putz, 2005); software used to prepare material for publication: WinGX (Farrugia, 1999).
![[Figure 1]](./ng2369fig1thm.gif)
| Fig. 1. The structure (I), showing 50% probability displacement ellipsoids. H atoms have been omitted for clarity. Primed atoms were generated by symmetry (−x, −y + 1, −z). |
![[Figure 2]](./ng2369fig2thm.gif)
| Fig. 2. Packing diagram of (I). |
![[Figure 3]](./ng2369fig3thm.gif)
| Fig. 3. Overlay of calculated and observed structures of (I) |
| [PtBr4(C2H6S)2] | F000 = 572 |
| Mr = 638.99 | Dx = 3.356 Mg m−3 |
| Monoclinic, P21/n | Mo Kα radiation λ = 0.71073 Å |
| Hall symbol: -P 2yn | Cell parameters from 7741 reflections |
| a = 7.1993 (2) Å | θ = 3.0–28.3º |
| b = 7.0922 (2) Å | µ = 24.01 mm−1 |
| c = 12.6033 (3) Å | T = 100 (2) K |
| β = 100.674 (1)º | Cuboid, red |
| V = 632.38 (3) Å3 | 0.14 × 0.07 × 0.06 mm |
| Z = 2 |
| Bruker X8 APEXII 4K Kappa CCD diffractometer | 1577 independent reflections |
| Monochromator: graphite | 1503 reflections with I > 2σ(I) |
| Detector resolution: 8.3 pixels mm-1 | Rint = 0.037 |
| T = 100(2) K | θmax = 28.3º |
| φ and ω scans | θmin = 3.0º |
| Absorption correction: multi-scan (SADABS; Bruker, 2004) | h = −9→9 |
| Tmin = 0.098, Tmax = 0.239 | k = −8→9 |
| 12836 measured reflections | l = −16→16 |
| Refinement on F2 | H-atom parameters constrained |
| Least-squares matrix: full | w = 1/[σ2(Fo2) + (0.0206P)2 + 0.9733P] where P = (Fo2 + 2Fc2)/3 |
| R[F2 > 2σ(F2)] = 0.019 | (Δ/σ)max = 0.001 |
| wR(F2) = 0.048 | Δρmax = 0.60 e Å−3 |
| S = 1.25 | Δρmin = −2.31 e Å−3 |
| 1577 reflections | Extinction correction: none |
| 54 parameters |
| [PtBr4(C2H6S)2] | V = 632.38 (3) Å3 |
| Mr = 638.99 | Z = 2 |
| Monoclinic, P21/n | Mo Kα |
| a = 7.1993 (2) Å | µ = 24.01 mm−1 |
| b = 7.0922 (2) Å | T = 100 (2) K |
| c = 12.6033 (3) Å | 0.14 × 0.07 × 0.06 mm |
| β = 100.674 (1)º |
| Bruker X8 APEXII 4K Kappa CCD diffractometer | 1577 independent reflections |
| Absorption correction: multi-scan (SADABS; Bruker, 2004) | 1503 reflections with I > 2σ(I) |
| Tmin = 0.098, Tmax = 0.239 | Rint = 0.037 |
| 12836 measured reflections |
| R[F2 > 2σ(F2)] = 0.019 | 54 parameters |
| wR(F2) = 0.048 | H-atom parameters constrained |
| S = 1.25 | Δρmax = 0.60 e Å−3 |
| 1577 reflections | Δρmin = −2.31 e Å−3 |
Experimental. The intensity data was collected on a Bruker X8 Apex II 4 K Kappa CCD diffractometer using an exposure time of 20 s/frame. A total of 2528 frames were collected with a frame width of 0.5° covering up to θ = 28.3° with 100% completeness accomplished. |
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. |
| x | y | z | Uiso*/Ueq | ||
| Pt | 0 | 0.5 | 0 | 0.00571 (7) | |
| Br1 | 0.12665 (5) | 0.42300 (6) | −0.16361 (3) | 0.01208 (10) | |
| Br2 | 0.26367 (5) | 0.32209 (5) | 0.10955 (3) | 0.01170 (9) | |
| S | 0.14169 (12) | 0.80085 (13) | 0.02722 (7) | 0.00895 (18) | |
| C1 | 0.2075 (6) | 0.8796 (6) | −0.0964 (3) | 0.0152 (8) | |
| H1A | 0.2529 | 1.0099 | −0.0878 | 0.023* | |
| H1B | 0.0974 | 0.8733 | −0.1551 | 0.023* | |
| H1C | 0.308 | 0.7984 | −0.1136 | 0.023* | |
| C2 | 0.3716 (5) | 0.7772 (6) | 0.1094 (3) | 0.0162 (8) | |
| H2A | 0.4487 | 0.6927 | 0.0737 | 0.024* | |
| H2B | 0.3599 | 0.7246 | 0.1797 | 0.024* | |
| H2C | 0.4323 | 0.9012 | 0.1196 | 0.024* |
| U11 | U22 | U33 | U12 | U13 | U23 | |
| Pt | 0.00420 (10) | 0.00743 (12) | 0.00574 (11) | 0.00062 (7) | 0.00159 (7) | 0.00040 (6) |
| Br1 | 0.01282 (18) | 0.0146 (2) | 0.01001 (18) | 0.00212 (15) | 0.00527 (14) | −0.00004 (14) |
| Br2 | 0.00882 (18) | 0.01303 (19) | 0.01265 (18) | 0.00292 (14) | 0.00047 (14) | 0.00183 (13) |
| S | 0.0078 (4) | 0.0087 (4) | 0.0109 (4) | −0.0010 (3) | 0.0033 (3) | −0.0007 (3) |
| C1 | 0.018 (2) | 0.015 (2) | 0.0149 (19) | −0.0038 (16) | 0.0078 (16) | 0.0043 (16) |
| C2 | 0.0117 (18) | 0.018 (2) | 0.018 (2) | −0.0045 (16) | −0.0012 (15) | −0.0021 (16) |
| Pt—S | 2.3624 (9) | S—C1 | 1.799 (4) |
| Pt—Si | 2.3624 (9) | C1—H1A | 0.98 |
| Pt—Br1i | 2.4654 (4) | C1—H1B | 0.98 |
| Pt—Br1 | 2.4654 (4) | C1—H1C | 0.98 |
| Pt—Br2 | 2.4761 (4) | C2—H2A | 0.98 |
| Pt—Br2i | 2.4761 (4) | C2—H2B | 0.98 |
| S—C2 | 1.790 (4) | C2—H2C | 0.98 |
| S—Pt—Si | 180 | C2—S—C1 | 99.6 (2) |
| S—Pt—Br1i | 83.98 (2) | C2—S—Pt | 109.11 (15) |
| Si—Pt—Br1i | 96.02 (2) | C1—S—Pt | 109.30 (14) |
| S—Pt—Br1 | 96.02 (2) | S—C1—H1A | 109.5 |
| Si—Pt—Br1 | 83.98 (2) | S—C1—H1B | 109.5 |
| Br1i—Pt—Br1 | 180 | H1A—C1—H1B | 109.5 |
| S—Pt—Br2 | 96.52 (2) | S—C1—H1C | 109.5 |
| Si—Pt—Br2 | 83.48 (2) | H1A—C1—H1C | 109.5 |
| Br1i—Pt—Br2 | 90.607 (12) | H1B—C1—H1C | 109.5 |
| Br1—Pt—Br2 | 89.393 (12) | S—C2—H2A | 109.5 |
| S—Pt—Br2i | 83.48 (2) | S—C2—H2B | 109.5 |
| Si—Pt—Br2i | 96.52 (2) | H2A—C2—H2B | 109.5 |
| Br1i—Pt—Br2i | 89.393 (12) | S—C2—H2C | 109.5 |
| Br1—Pt—Br2i | 90.607 (12) | H2A—C2—H2C | 109.5 |
| Br2—Pt—Br2i | 180 | H2B—C2—H2C | 109.5 |
| Br1i—Pt—S—C2 | 91.04 (15) | Br1i—Pt—S—C1 | −161.04 (15) |
| Br1—Pt—S—C2 | −88.96 (15) | Br1—Pt—S—C1 | 18.96 (15) |
| Br2—Pt—S—C2 | 1.11 (15) | Br2—Pt—S—C1 | 109.04 (15) |
| Br2i—Pt—S—C2 | −178.89 (15) | Br2i—Pt—S—C1 | −70.96 (15) |
| Symmetry codes: (i) −x, −y+1, −z. |
| X | Pt—X1 | Pt—X2 | Pt—S | X1—Pt—S | X2—Pt—S | X1—Pt—X2 |
| Cl (i) | 2.313 (3) | 2.319 (33) | 2.363 (10) | 95.68 (5) | 83.43 (4) | 90.42 (5) |
| Br (ii) | 2.475 (1) | 2.467 (1) | 2.364 (2) | 96.05 (7) | 83.75 (6) | 90.57 (4) |
| Br (iii) | 2.4654 (4) | 2.4761 (4) | 2.3624 (9) | 96.02 (2) | 83.48 (2) | 90.607 (12) |
| Br (iv) | 2.558 | 2.558 | 2.440 | 96.88 | 83.30 | 89.89 |
| (i) Toffoli et al. (1987); (ii) Skvortsov et al. (1994); (iii) this work, observed; (iv) this work, calculated. |
Financial assistance from the South African National Research Foundation, the Research Fund of the University of the Free State and SASOL is gratefully acknowledged. Part of this material is based on work supported by the South African National Research Foundation (SA NRF, GUN 2038915). Opinions, findings, conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the NRF.
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As part of an ongoing investigation (Muller et al., 2006; Roodt et al., 2003; Otto, 2001; Otto et al., 2000) into determining which factors govern a disordered packing mode in symmetrical square-planar complexes of Rh, Ir, Pd and Pt we set out to synthesize the starting compound trans-[PtBr2(dms)2], however we formed trans-[PtBr4(dms)2].
The current redetermination of the structure (Skvortsov et al., 1994) is accompanied by a DFT calculation to determine the optimum structure in the gas phase, similar to what we reported previously for square planar Rh complexes (Muller et al., 2006).
The title compound trans-[PtBr4(dms)2] (dms = SMe2), (I), crystallizes in the monoclinic space group P2(1)/n (Z = 2) and lies on an inversion centre (Figure 1). Selected geometrical data are given in Table 2. The Pt—Br distances of the current low temperature study are slightly smaller than the previously reported, room temperature, structure (Skvortsov et al., 1994; data extracted from the Cambridge Structural Database; Version 5.27, update of August 2006), as is to be expected. No short intermolecular contacts were observed. A packing diagram is given in Figure 2.
Geometry optimization of the title compound using Density Functional Theory (DFT) calculations with the observed parameters as a starting structure converged to similar geometry. A good agreement between the calculated and observed geometry (Table 3) was found (r.m.s. deviation of all non-H atoms = 0.1684 Å). The overlay of the calculated and experimental structures is shown in Figure 3.
The geometries of trans-[PtX4(dms)2] (X = Cl, Br, I) which are isostructural are given in Table 3. The Pt—S distances are about the same for X = Cl and Br, 2.36 Å. The X—Pt—X angles are close to 90° for all complexes and the X—Pt—S angles are 5–7° off the 'ideal' 90°. Recently (Janse van Rensburg et al., 2007) the iodo complex has been described as being suspended by I···I contacts, and we refer to their discussion of these contacts.