(μ₄-Disulfido-1:2κ²S,S;3:4κ²S′,S′)bis­(μ₂-ethyl­thiol­ato-κ²S:S)tetra­kis[tricarbonyl­iron(II)(Fe—Fe)]

The title compound, [Fe₄(SEt)₂(S₂)(CO)₁₂], contains two inversion-related [Fe₂(SEt)(CO)₆] subclusters linked by a disulfide bond [S—S 2.1294 (14) Å]. In each subcluster, each Fe^II atom is coordinated by three terminal carbon­yl C atoms [Fe—C 1.792 (3)–1.814 (4) Å], two bridging S atoms [Fe—S 2.2496 (9)–2.2606 (8) Å] and the other Fe atom [Fe—Fe = 2.5311 (7) Å], and exhibits a distorted octa­hedral geometry, with trans angles ranging from 155.56 (12) to 160.14 (15)°.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.006 Å
• R factor = 0.040
• wR factor = 0.094
• Data-to-parameter ratio = 18.8

checkCIF/PLATON results

No syntax errors found



Alert level A
DIFF019_ALERT_1_A  _diffrn_standards_number is missing
            Number of standards used in measurement.
DIFF020_ALERT_1_A  _diffrn_standards_interval_count and
            _diffrn_standards_interval_time are missing. Number of measurements
            between standards or time (min) between standards.

Alert level C
PLAT232_ALERT_2_C Hirshfeld Test Diff (M-X)  Fe1    -   C5      ..       5.26 su
PLAT232_ALERT_2_C Hirshfeld Test Diff (M-X)  Fe1    -   C6      ..       5.98 su
PLAT232_ALERT_2_C Hirshfeld Test Diff (M-X)  Fe2    -   C1      ..       6.58 su
PLAT232_ALERT_2_C Hirshfeld Test Diff (M-X)  Fe2    -   C3      ..       7.00 su

   2 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   4 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   4 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: CrystalClear (Rigaku, 2000); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXTL (Siemens, 1994); program(s) used to refine structure: SHELXTL (Siemens, 1994); molecular graphics: SHELXTL (Sheldrick, 1997); software used to prepare material for publication: SHELXTL (Sheldrick, 1997).

(µ₄-Disulfido-1:2κ²S;3:4κ²S')bis(µ₂-ethylthiolato- κ²Fe,Fe')tetrakis[tricarbonyliron(II)(Fe—Fe)]

Crystal data

[Fe4(C2H5)2(S2)(CO)12]	F(000) = 740
Mr = 745.88	Dx = 1.839 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 2637 reflections
a = 10.4820 (11) Å	θ = 3.1–27.5°
b = 13.1288 (15) Å	µ = 2.48 mm^−1
c = 10.0749 (11) Å	T = 298 K
β = 103.719 (4)°	Prism, red
V = 1346.9 (3) Å^3	0.25 × 0.20 × 0.10 mm
Z = 2

Data collection

Bruker P4 diffractometer	3070 independent reflections
Radiation source: fine-focus sealed tube	2417 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.031
ω scans	θmax = 27.5°, θmin = 3.1°
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996)	h = −13→13
Tmin = 0.525, Tmax = 0.781	k = −17→16
10263 measured reflections	l = −12→12

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.040	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.094	H-atom parameters constrained
S = 1.06	w = 1/[σ^2(Fo^2) + (0.0451P)^2 + 0.0725P] where P = (Fo^2 + 2Fc^2)/3
3070 reflections	(Δ/σ)max = 0.001
163 parameters	Δρmax = 0.36 e Å^−3
0 restraints	Δρmin = −0.27 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
Fe1	0.73694 (4)	0.59944 (3)	0.11792 (4)	0.04750 (15)
Fe2	0.73302 (4)	0.40770 (3)	0.14287 (4)	0.04290 (14)
S1	0.65680 (7)	0.51829 (6)	0.27782 (8)	0.04353 (19)
S2	0.59438 (7)	0.49581 (6)	−0.02187 (8)	0.0467 (2)
C1	0.6401 (3)	0.2968 (3)	0.1720 (4)	0.0584 (8)
C2	0.8054 (3)	0.3616 (3)	0.0097 (4)	0.0631 (9)
C3	0.8830 (3)	0.3841 (2)	0.2677 (3)	0.0536 (8)
C4	0.6511 (4)	0.7187 (3)	0.1163 (4)	0.0674 (10)
C5	0.8100 (4)	0.6194 (3)	−0.0244 (4)	0.0753 (11)
C6	0.8880 (3)	0.6320 (3)	0.2371 (4)	0.0594 (8)
C7	0.7598 (3)	0.5298 (3)	0.4504 (3)	0.0577 (8)
H7A	0.8502	0.5144	0.4497	0.069*
H7B	0.7564	0.5992	0.4825	0.069*
C8	0.7144 (4)	0.4585 (4)	0.5448 (4)	0.0852 (12)
H8A	0.7696	0.4654	0.6352	0.128*
H8B	0.7190	0.3898	0.5137	0.128*
H8C	0.6254	0.4743	0.5464	0.128*
O1	0.5819 (3)	0.2290 (2)	0.1935 (3)	0.0941 (10)
O2	0.8512 (3)	0.3327 (3)	−0.0749 (3)	0.0989 (10)
O3	0.9793 (2)	0.3694 (2)	0.3445 (3)	0.0775 (8)
O4	0.5978 (3)	0.7937 (2)	0.1185 (4)	0.1044 (11)
O5	0.8561 (3)	0.6317 (3)	−0.1142 (3)	0.1226 (14)
O6	0.9834 (3)	0.6520 (2)	0.3111 (3)	0.0851 (8)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Fe1	0.0326 (2)	0.0574 (3)	0.0506 (3)	−0.00636 (19)	0.00611 (19)	0.0052 (2)
Fe2	0.0297 (2)	0.0541 (3)	0.0420 (3)	0.00187 (18)	0.00258 (17)	−0.00441 (19)
S1	0.0344 (4)	0.0536 (4)	0.0418 (4)	−0.0013 (3)	0.0076 (3)	−0.0023 (3)
S2	0.0276 (3)	0.0691 (5)	0.0408 (4)	−0.0007 (3)	0.0032 (3)	0.0027 (3)
C1	0.050 (2)	0.063 (2)	0.060 (2)	0.0025 (17)	0.0098 (17)	−0.0058 (17)
C2	0.0383 (17)	0.091 (3)	0.055 (2)	0.0068 (18)	0.0010 (15)	−0.015 (2)
C3	0.0434 (18)	0.0610 (19)	0.0538 (19)	0.0054 (15)	0.0063 (15)	−0.0092 (16)
C4	0.056 (2)	0.061 (2)	0.084 (3)	−0.0052 (18)	0.014 (2)	0.013 (2)
C5	0.047 (2)	0.109 (3)	0.068 (2)	−0.022 (2)	0.0101 (18)	0.013 (2)
C6	0.0450 (19)	0.066 (2)	0.066 (2)	−0.0111 (17)	0.0100 (17)	0.0057 (18)
C7	0.053 (2)	0.074 (2)	0.0422 (18)	0.0007 (17)	0.0045 (15)	−0.0083 (16)
C8	0.079 (3)	0.119 (3)	0.054 (2)	0.003 (3)	0.009 (2)	0.020 (2)
O1	0.096 (2)	0.0720 (17)	0.120 (3)	−0.0223 (16)	0.037 (2)	−0.0019 (17)
O2	0.076 (2)	0.151 (3)	0.0732 (19)	0.0187 (19)	0.0257 (16)	−0.0343 (19)
O3	0.0467 (14)	0.102 (2)	0.0691 (17)	0.0137 (14)	−0.0154 (12)	−0.0072 (15)
O4	0.102 (2)	0.0674 (17)	0.148 (3)	0.0162 (17)	0.039 (2)	0.0170 (19)
O5	0.091 (2)	0.207 (4)	0.080 (2)	−0.050 (2)	0.0404 (19)	0.013 (2)
O6	0.0512 (15)	0.109 (2)	0.0843 (19)	−0.0266 (16)	−0.0052 (14)	0.0008 (17)

Geometric parameters (Å, º)

Fe1—C6	1.797 (4)	C1—O1	1.129 (4)
Fe1—C5	1.798 (4)	C2—O2	1.137 (4)
Fe1—C4	1.804 (4)	C3—O3	1.134 (4)
Fe1—S2	2.2515 (9)	C4—O4	1.134 (4)
Fe1—S1	2.2535 (8)	C5—O5	1.133 (4)
Fe1—Fe2	2.5311 (7)	C6—O6	1.127 (4)
Fe2—C3	1.792 (3)	C7—C8	1.491 (5)
Fe2—C2	1.797 (3)	C7—H7A	0.9700
Fe2—C1	1.814 (4)	C7—H7B	0.9700
Fe2—S2	2.2496 (9)	C8—H8A	0.9600
Fe2—S1	2.2606 (8)	C8—H8B	0.9600
S1—C7	1.823 (3)	C8—H8C	0.9600
S2—S2^i	2.1294 (14)
C6—Fe1—C5	91.35 (16)	C1—Fe2—Fe1	146.75 (10)
C6—Fe1—C4	99.12 (17)	S2—Fe2—Fe1	55.82 (2)
C5—Fe1—C4	99.93 (19)	S1—Fe2—Fe1	55.76 (2)
C6—Fe1—S2	155.56 (12)	C7—S1—Fe1	113.95 (12)
C5—Fe1—S2	86.23 (13)	C7—S1—Fe2	114.38 (12)
C4—Fe1—S2	105.25 (12)	Fe1—S1—Fe2	68.21 (3)
C6—Fe1—S1	93.07 (11)	S2^i—S2—Fe2	110.08 (5)
C5—Fe1—S1	160.14 (15)	S2^i—S2—Fe1	110.53 (5)
C4—Fe1—S1	98.46 (12)	Fe2—S2—Fe1	68.43 (3)
S2—Fe1—S1	81.77 (3)	O1—C1—Fe2	178.1 (3)
C6—Fe1—Fe2	101.68 (11)	O2—C2—Fe2	179.8 (4)
C5—Fe1—Fe2	104.12 (15)	O3—C3—Fe2	178.5 (3)
C4—Fe1—Fe2	147.59 (11)	O4—C4—Fe1	178.4 (4)
S2—Fe1—Fe2	55.75 (2)	O5—C5—Fe1	179.8 (5)
S1—Fe1—Fe2	56.03 (2)	O6—C6—Fe1	179.4 (4)
C3—Fe2—C2	90.59 (14)	C8—C7—S1	110.5 (3)
C3—Fe2—C1	99.40 (16)	C8—C7—H7A	109.6
C2—Fe2—C1	100.86 (16)	S1—C7—H7A	109.6
C3—Fe2—S2	155.83 (11)	C8—C7—H7B	109.6
C2—Fe2—S2	86.31 (12)	S1—C7—H7B	109.6
C1—Fe2—S2	104.73 (11)	H7A—C7—H7B	108.1
C3—Fe2—S1	93.74 (10)	C7—C8—H8A	109.5
C2—Fe2—S1	159.73 (13)	C7—C8—H8B	109.5
C1—Fe2—S1	97.94 (10)	H8A—C8—H8B	109.5
S2—Fe2—S1	81.65 (3)	C7—C8—H8C	109.5
C3—Fe2—Fe1	102.08 (11)	H8A—C8—H8C	109.5
C2—Fe2—Fe1	103.97 (13)	H8B—C8—H8C	109.5

Symmetry code: (i) −x+1, −y+1, −z.