supplementary materials


vn2067 scheme

Acta Cryst. (2013). E69, m269-m270    [ doi:10.1107/S1600536813009860 ]

[[mu]-3-(Methylsulfanyl)benzene-1,2-dithiolato-1:2[kappa]4S,S':S,S']bis[tricarbonyliron(I)]

Y. Yang, N. Wang and L. Chen

Abstract top

The title compound, [Fe2(C7H6S3)(CO)6], was prepared as a biomimic for the active site of [FeFe]-hydrogenases. The central Fe2S2 core is in a butterfly conformation and each FeI atom has a pseudo-square-pyramidal coordination by three O atoms and two S atoms. The Fe-Fe distance is 2.471 (2) Å and the dihedral angle between the two Fe-S-Fe planes is 78.96 (7)°. The least-squares plane through the -S(C7H6S)S- bridge nearly bisects the molecular structure: except for the two Fe(CO)3 units, all atoms are in this plane with an average deviation from the plane of 0.028 (3) Å. In the crystal, the molecules are linked into chains along [001] by C-H...[pi](arene) interactions.

Comment top

[FeFe]-hydrogenases are important enzymes in numerous microorganisms, which can catalyse hydrogen evolution or uptake. Crystallographic and IR spectroscopic studies on the two types of [FeFe]Hases, CpI (Clostridium pasteurianum) and DdH (Desulfovibrio desulfuricans), revealed that the active site of [FeFe]-hydrogenases is comprised of a 2Fe2S butterfly structure, which contains diatomic ligands CO and CN-, a cysteinyl-S ligand connecting to a 4Fe4S subcluster, and a three-atom linker (–CH2XCH2–, X = CH2,NH or O) bridged between the two S atoms of the Fe2S2 H-cluster (Capon et al., 2009, Tard & Pickett, 2009). It was found that the introduction of a rigid and conjugate bridge to the Fe2S2 complexes could make the electrochemical properties of the complexes apparently different from the Fe2S2 complexes with flexible bridges (Capon et al., 2009).

The structure of the title compound resembles the active site of [FeFe]-hydrogenases, with a butterfly architectonic 2Fe2S core and the usual distorted square-pyramidal geometry around the iron center (Wang et al., 2005, Dong et al., 2006). The length of the Fe–Fe bond [2.471 (2) Å] is slightly shorter than those in the structures of natural enzymes (ca 2.6 Å) (Peters et al., 1998, Nicolet et al., 1999). The dihedral angle between two Fe–S–Fe planes is 78.96 (7) °. The rigid dithiolate bridge is a special feature for the title compound. The molecular structure has an internal pseudo-mirror plane passing through the aromatic ring. The calculated plane of the SRS bridge is nearly a bisecting plane of the molecular structure. Except for two Fe(CO)3 units all atoms are in the plane with the average deviation of 0.0280 Å. The deviations of the iron atoms from the SRS basal plane are 1.266 (5) Å for Fe(1) and 1.205 (5) Å for Fe(2). The molecular structure of the title compound is shown in Figure 1.

Related literature top

For general background to [FeFe]-hydrogenases, see: Capon et al. (2009); Tard & Pickett (2009). For the crystal structure of the natural enzyme, see: Peters et al. (1998); Nicolet et al. (1999). For related structures and the synthesis, see: Maiolo et al. (1981); Wang et al. (2005); Dong et al. (2006).

Experimental top

All reactions and operations related to the title compound were carried out under a dry, prepurified nitrogen atmosphere with standard Schlenk techniques. All solvents were dried and distilled prior to use according to standard methods. The starting material 3-(methylthio)benzene-1,2-dilthiol was prepared by a similar procedure according to the literature (Maiolo et al., 1981). 3-(Methylthio)benzene-1,2-dilthiol (1 mmol, 0.188 g) and freshly synthesized Fe3(CO)12 (1 mmol, 0.503 g) were refluxed in toluene under N2 atmosphere for 3 h. The color of the solution changed gradually from dark green to dark red. The solvent was removed under reduced pressure. The residue was purified by column chromatography on silica gel using hexane as eluent to give the title compound as a red solid (0.294 g, 63%). A single-crystal suitable for X-ray study was obtained by slow evaporation of CH2Cl2/hexane (1:10, v/v) solution at room temperature. IR (CH2Cl2, cm-1): ν(CO) 2075 (m), 2045 (s), 1999 (versus); 1H NMR (400 MHz, CDCl3): δ 6.92 (s, 1H, C6H3), 6.60 (s, 1H, C6H3), 6.53 (s, 1H, C6H3), 2.41 (s, 3H, SCH3).

Refinement top

Hydrogen atoms were positioned geometrically and refined as riding atoms, with C–H = 0.93 (CH) and 0.96 (CH3) Å and with Uiso(H) = 1.2 (1.5 for methyl) Ueq(C).

Computing details top

Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT-Plus (Bruker, 2007); data reduction: SAINT-Plus (Bruker, 2007); 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: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. Molecular structure of the title compound, with displacement ellipsoids drawn at the 30% probability level.
[µ-3-(Methylsulfanyl)benzene-1,2-dithiolato-1:2κ4S,S':S,S']bis[tricarbonyliron(I)] top
Crystal data top
[Fe2(C7H6S3)(CO)6]F(000) = 928
Mr = 466.06Dx = 1.801 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 2629 reflections
a = 16.531 (17) Åθ = 2.5–27.1°
b = 7.975 (8) ŵ = 2.08 mm1
c = 13.047 (13) ÅT = 295 K
β = 92.055 (13)°Block, red
V = 1719 (3) Å30.39 × 0.24 × 0.08 mm
Z = 4
Data collection top
Bruker APEXII CCD
diffractometer
3024 independent reflections
Radiation source: fine-focus sealed tube2098 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.055
φ and ω scansθmax = 25.0°, θmin = 2.5°
Absorption correction: multi-scan
(SADABS; Bruker, 2001)
h = 1918
Tmin = 0.555, Tmax = 0.847k = 99
8260 measured reflectionsl = 1513
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)] = 0.036Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.084H-atom parameters constrained
S = 0.97 w = 1/[σ2(Fo2) + (0.0341P)2]
where P = (Fo2 + 2Fc2)/3
3024 reflections(Δ/σ)max < 0.001
217 parametersΔρmax = 0.44 e Å3
0 restraintsΔρmin = 0.31 e Å3
Crystal data top
[Fe2(C7H6S3)(CO)6]V = 1719 (3) Å3
Mr = 466.06Z = 4
Monoclinic, P21/cMo Kα radiation
a = 16.531 (17) ŵ = 2.08 mm1
b = 7.975 (8) ÅT = 295 K
c = 13.047 (13) Å0.39 × 0.24 × 0.08 mm
β = 92.055 (13)°
Data collection top
Bruker APEXII CCD
diffractometer
3024 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2001)
2098 reflections with I > 2σ(I)
Tmin = 0.555, Tmax = 0.847Rint = 0.055
8260 measured reflectionsθmax = 25.0°
Refinement top
R[F2 > 2σ(F2)] = 0.036H-atom parameters constrained
wR(F2) = 0.084Δρmax = 0.44 e Å3
S = 0.97Δρmin = 0.31 e Å3
3024 reflectionsAbsolute structure: ?
217 parametersFlack parameter: ?
0 restraintsRogers parameter: ?
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
Fe10.17590 (2)0.29795 (7)0.64150 (4)0.04642 (17)
Fe20.18906 (3)0.54555 (7)0.52941 (4)0.04814 (18)
S30.46296 (5)0.53167 (12)0.73543 (7)0.0462 (2)
S20.22860 (5)0.28468 (12)0.48479 (7)0.0475 (2)
S10.27674 (5)0.48911 (12)0.66349 (7)0.0446 (2)
C80.35707 (16)0.3899 (4)0.5983 (2)0.0354 (7)
C100.3893 (2)0.2051 (4)0.4606 (3)0.0481 (9)
H10A0.37300.13750.40550.058*
C20.0831 (2)0.2118 (5)0.5909 (3)0.0560 (10)
C90.33421 (18)0.2915 (4)0.5159 (3)0.0401 (8)
C50.1075 (2)0.5260 (5)0.4373 (4)0.0605 (11)
C10.21760 (19)0.1120 (6)0.6991 (3)0.0564 (10)
C70.43793 (17)0.4062 (4)0.6280 (3)0.0377 (8)
C110.4698 (2)0.2221 (5)0.4897 (3)0.0514 (9)
H11A0.50860.16480.45350.062*
C120.49397 (19)0.3216 (4)0.5709 (3)0.0449 (9)
H12A0.54880.33240.58790.054*
O20.02428 (15)0.1593 (4)0.5570 (3)0.0859 (10)
O10.24308 (17)0.0076 (4)0.7338 (3)0.0867 (11)
C40.2506 (2)0.6882 (6)0.4606 (4)0.0700 (12)
O50.05695 (18)0.5075 (4)0.3771 (3)0.0918 (11)
O60.09707 (19)0.7802 (4)0.6518 (3)0.0961 (12)
O40.2905 (2)0.7821 (5)0.4201 (3)0.1088 (13)
O30.09360 (19)0.4359 (5)0.8164 (3)0.0994 (12)
C60.1338 (2)0.6903 (5)0.6042 (4)0.0643 (12)
C30.1254 (2)0.3805 (6)0.7494 (4)0.0631 (11)
C130.57037 (19)0.5072 (4)0.7506 (3)0.0543 (10)
H13A0.59000.57210.80820.082*
H13B0.59560.54540.68970.082*
H13C0.58310.39110.76190.082*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Fe10.0379 (3)0.0561 (4)0.0452 (3)0.0011 (2)0.0000 (2)0.0002 (3)
Fe20.0429 (3)0.0491 (4)0.0522 (4)0.0050 (2)0.0029 (2)0.0011 (3)
S30.0421 (4)0.0487 (6)0.0479 (6)0.0040 (4)0.0011 (4)0.0067 (5)
S20.0480 (4)0.0519 (6)0.0422 (6)0.0004 (4)0.0046 (4)0.0077 (5)
S10.0379 (4)0.0538 (6)0.0423 (6)0.0033 (4)0.0016 (4)0.0123 (4)
C80.0392 (15)0.036 (2)0.0313 (19)0.0026 (15)0.0060 (13)0.0023 (16)
C100.061 (2)0.046 (2)0.038 (2)0.0035 (18)0.0044 (17)0.0051 (18)
C20.052 (2)0.058 (3)0.057 (3)0.0055 (19)0.0012 (18)0.002 (2)
C90.0433 (16)0.040 (2)0.037 (2)0.0048 (15)0.0035 (14)0.0003 (17)
C50.052 (2)0.061 (3)0.068 (3)0.0124 (19)0.001 (2)0.002 (2)
C10.0372 (17)0.070 (3)0.061 (3)0.0023 (19)0.0012 (17)0.001 (2)
C70.0405 (16)0.0300 (19)0.043 (2)0.0003 (14)0.0051 (14)0.0067 (16)
C110.056 (2)0.050 (2)0.050 (3)0.0106 (18)0.0194 (17)0.003 (2)
C120.0416 (17)0.046 (2)0.048 (2)0.0045 (16)0.0079 (15)0.0058 (19)
O20.0549 (15)0.087 (2)0.115 (3)0.0205 (15)0.0156 (17)0.004 (2)
O10.0665 (18)0.085 (2)0.108 (3)0.0094 (17)0.0127 (18)0.028 (2)
C40.062 (2)0.069 (3)0.079 (3)0.006 (2)0.005 (2)0.006 (3)
O50.0720 (19)0.109 (3)0.092 (3)0.0123 (17)0.034 (2)0.008 (2)
O60.083 (2)0.088 (3)0.117 (3)0.0311 (18)0.0015 (19)0.043 (2)
O40.101 (2)0.096 (3)0.130 (4)0.025 (2)0.021 (2)0.030 (3)
O30.087 (2)0.145 (3)0.068 (3)0.028 (2)0.0250 (19)0.007 (2)
C60.048 (2)0.064 (3)0.080 (3)0.004 (2)0.011 (2)0.005 (3)
C30.0422 (19)0.087 (3)0.060 (3)0.005 (2)0.0038 (19)0.007 (3)
C130.0432 (18)0.055 (3)0.064 (3)0.0049 (16)0.0044 (17)0.001 (2)
Geometric parameters (Å, º) top
Fe1—C11.789 (5)C8—C91.373 (4)
Fe1—C21.786 (4)C10—C91.368 (5)
Fe1—C31.788 (5)C10—C111.378 (5)
Fe1—Fe22.471 (2)C10—H10A0.9300
Fe1—S12.2695 (19)C11—C121.372 (5)
Fe1—S22.253 (2)C11—H11A0.9300
Fe2—C41.789 (5)C12—H12A0.9300
Fe2—C51.781 (4)C13—H13A0.9600
Fe2—C61.784 (5)C13—H13B0.9600
Fe2—S12.2763 (19)C13—H13C0.9600
Fe2—S22.263 (2)O3—C31.127 (5)
C1—O11.131 (4)O6—C61.139 (5)
C2—O21.133 (4)S1—C81.787 (3)
C4—O41.140 (5)S2—C91.779 (3)
C5—O51.135 (5)S3—C71.759 (4)
C7—C121.385 (5)S3—C131.790 (4)
C8—C71.385 (4)
C2—Fe1—C390.77 (19)C8—S1—Fe1101.39 (13)
C2—Fe1—C198.59 (17)C8—S1—Fe2100.67 (13)
C3—Fe1—C199.1 (2)Fe1—S1—Fe265.86 (5)
C2—Fe1—S290.09 (15)C9—C8—C7120.6 (3)
C3—Fe1—S2159.76 (15)C9—C8—S1115.9 (2)
C1—Fe1—S2100.74 (14)C7—C8—S1123.4 (2)
C2—Fe1—S1157.30 (13)C9—C10—C11117.3 (3)
C3—Fe1—S190.84 (14)C9—C10—H10A121.3
C1—Fe1—S1103.50 (13)C11—C10—H10A121.3
S2—Fe1—S180.80 (5)O2—C2—Fe1178.5 (4)
C2—Fe1—Fe2100.45 (13)C10—C9—C8122.1 (3)
C3—Fe1—Fe2103.00 (16)C10—C9—S2122.0 (3)
C1—Fe1—Fe2150.44 (12)C8—C9—S2115.9 (2)
S2—Fe1—Fe257.01 (5)O5—C5—Fe2177.1 (4)
S1—Fe1—Fe257.20 (5)O1—C1—Fe1178.4 (4)
C5—Fe2—C692.06 (19)C8—C7—C12117.4 (3)
C5—Fe2—C498.5 (2)C8—C7—S3118.3 (2)
C6—Fe2—C4100.1 (2)C12—C7—S3124.3 (2)
C5—Fe2—S287.98 (13)C12—C11—C10121.5 (3)
C6—Fe2—S2153.34 (15)C12—C11—H11A119.3
C4—Fe2—S2106.31 (16)C10—C11—H11A119.3
C5—Fe2—S1161.32 (14)C11—C12—C7121.0 (3)
C6—Fe2—S191.81 (15)C11—C12—H12A119.5
C4—Fe2—S198.82 (15)C7—C12—H12A119.5
S2—Fe2—S180.45 (5)O4—C4—Fe2177.5 (5)
C5—Fe2—Fe1104.41 (14)O6—C6—Fe2178.4 (4)
C6—Fe2—Fe197.78 (16)O3—C3—Fe1178.5 (5)
C4—Fe2—Fe1150.30 (13)S3—C13—H13A109.5
S2—Fe2—Fe156.64 (3)S3—C13—H13B109.5
S1—Fe2—Fe156.94 (5)H13A—C13—H13B109.5
C7—S3—C13103.30 (16)S3—C13—H13C109.5
C9—S2—Fe1101.52 (13)H13A—C13—H13C109.5
C9—S2—Fe2101.73 (12)H13B—C13—H13C109.5
Fe1—S2—Fe266.35 (4)
Hydrogen-bond geometry (Å, º) top
Cg1 is the centroid of the C7–C12 ring.
D—H···AD—HH···AD···AD—H···A
C13—H13A···Cg1i0.962.693.590 (5)157
Symmetry code: (i) x+1, y+1/2, z+3/2.
Selected bond lengths (Å) top
Fe1—C11.789 (5)Fe2—C41.789 (5)
Fe1—C21.786 (4)Fe2—C51.781 (4)
Fe1—C31.788 (5)Fe2—C61.784 (5)
Fe1—S12.2695 (19)Fe2—S12.2763 (19)
Fe1—S22.253 (2)Fe2—S22.263 (2)
Hydrogen-bond geometry (Å, º) top
Cg1 is the centroid of the C7–C12 ring.
D—H···AD—HH···AD···AD—H···A
C13—H13A···Cg1i0.962.693.590 (5)157
Symmetry code: (i) x+1, y+1/2, z+3/2.
Acknowledgements top

We are grateful to the Chinese National Natural Science Foundation (grant No. 21101057), the Doctoral Fund of Henan University of Technology (No. 2009BS053) and the Science Foundation of the Education Department of Henan Province (No. 2011B150006) for support.

references
References top

Bruker (2001). SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.

Bruker (2007). SAINT-Plus and APEX2. Bruker AXS Inc., Madison, Wisconsin, USA.

Capon, J.-F., Gloaguen, F., Pétillon, F. Y., Schollhammer, P. & Talarmin, J. (2009). Coord. Chem. Rev. 253, 1476–1494.

Dong, W., Wang, M., Liu, X., Jin, K., Li, G., Wang, F. & Sun, L. (2006). Chem. Commun. pp. 305–307.

Maiolo, F., Testaferri, L., Tiecco, M. & Tingoli, M. (1981). J. Org. Chem. 46, 3070–3073.

Nicolet, Y., Piras, C., Legrand, P., Hatchikian, C. E. & Fontecilla-Camps, J. C. (1999). Structure, 7, 13–23.

Peters, J. W., Lanzilotta, W. N., Lemon, B. J. & Seefeldt, L. C. (1998). Science 282, 1853–1858.

Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.

Tard, C. & Pickett, C. J. (2009). Chem. Rev. 109, 2245–2274.

Wang, F., Wang, M., Liu, X., Jin, K., Dong, W., Li, G., Åkermark, B. & Sun, L. (2005). Chem. Commun. pp. 3221–3223.