Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536801016154/ya6054sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536801016154/ya6054Isup2.hkl |
CCDC reference: 175981
The compound was prepared in 66% yield as a dark red solid, decomposing at 373 K, according to the procedure described previously (Seyferth & White, 1971).
Hydrogen atoms were placed in calculated positions and included in the refinement in the riding motion approximation with Uiso constrained to be 1.5 times Ueq of the carrier atom for the methyl-H and 1.2 times Ueq for the remaining H atoms. The highest peak in the final difference map is at a distance of 0.84 Å from Sn2.
The title compound (I) was prepared thirty years ago, but the nature of the bonding in the crystal remained unknown until now. The tin–carbon bond in stannyl alkynes is relatively labile, though these can be used in Stille-type palladium-catalysed cross-coupling reactions with organyl halides (Mitchell, 1998). However, the reactivity of the carbon–carbon triple bond is such that oligomeric and polymeric side-products are obtained in large amounts. Complexation of the carbon–carbon triple bond by the dicobalt hexacarbonyl moiety to give a dicobaltatetrahedrane structure does not hinder cross-coupling with activated organyl halides (Zavgorodnii et al., 2000). The title compound is air- and moisture-insensitive, whereas the uncomplexed bis(trimethylstannyl)acetylene is easily hydrolysed by atmospheric moisture.
Only one dicobaltatetrahedrane derived from a stannyl alkyne has so far been studied by X-ray crystallography (Wrackmeyer et al., 1997) but this compound (A) could be atypical for steric reasons, as it is prepared by reacting diphenyldiethynyltin Ph2Sn(C≡CH)2 with dicobalt octacarbonyl, both acetylenic bonds being converted to dicobaltatetrahedrane moieties.
The structure of (I) is shown in Fig. 1. The length of the complexed acetylenic triple bond in this structure is 1.309 (5) Å, as compared with 1.238 Å in the uncomplexed stannyl acetylene and 1.212 (1) Å in acetylene itself (Khaikin et al., 2000); it is markedly shorter than in (A) [1.322 (9) and 1.335 (9) Å]. The cobalt–cobalt distance (2.5043 (9) Å) is considerably longer than in (A) [2.4788 (2) and 2.487 (2) Å]. While in (A) the cobalt–carbon bond lengths in the dicobaltatetrahedrane moiety lie between 1.944 and 1.990 Å (the authors describe these as "normal" values), all four Co—C bonds in the title compound are equal or longer than 2.000 Å (up to 2.007 Å). The originally linear Sn—C—C—Sn arrangement is naturally considerably bent, the angles Sn—C—C being 144.7 (3)° and 145.7 (3)°; in (A), however, the bond angles are much larger at 150.5 (5) and 151.5 (5)°.
Data collection: CAD4 Version 5.0 (Nonius, 1989); cell refinement: CAD4 Version 5.0 (Nonius, 1989); data reduction: XCAD4 (Harms, 1996); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL-Plus (Sheldrick, 1991); software used to prepare material for publication: SHELXL97 (Sheldrick, 1997), PARST95 (Nardelli, 1995).
Fig. 1. : View of the title compound showing the labelling of all non-H atoms. Displacement ellipsoids are shown at the 30% probability level. H atoms are omitted for clarity. |
[Co2(C8H18Sn2)(CO)6] | Z = 2 |
Mr = 637.52 | F(000) = 608 |
Triclinic, P1 | Dx = 1.942 Mg m−3 |
a = 8.659 (4) Å | Ag Kα radiation, λ = 0.56083 Å |
b = 10.0360 (17) Å | Cell parameters from 25 reflections |
c = 13.292 (3) Å | θ = 12.1–15.4° |
α = 91.731 (16)° | µ = 1.98 mm−1 |
β = 91.17 (3)° | T = 293 K |
γ = 109.09 (2)° | Plate, red-brown |
V = 1090.5 (6) Å3 | 0.40 × 0.30 × 0.05 mm |
Nonius CAD-4 diffractometer | 3813 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.019 |
Graphite monochromator | θmax = 21.0°, θmin = 3.0° |
ω/2θ scans | h = −11→11 |
Absorption correction: ψ scan (WinGX; Farrugia, 1999; North et al., 1968) | k = −12→12 |
Tmin = 0.620, Tmax = 0.997 | l = −16→16 |
9426 measured reflections | 3 standard reflections every 60 min |
4713 independent reflections | intensity decay: none |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.034 | H-atom parameters constrained |
wR(F2) = 0.091 | w = 1/[σ2(Fo2) + (0.0639P)2] where P = (Fo2 + 2Fc2)/3 |
S = 1.03 | (Δ/σ)max = 0.002 |
4713 reflections | Δρmax = 1.15 e Å−3 |
224 parameters | Δρmin = −1.54 e Å−3 |
0 restraints | Extinction correction: SHELXL, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0075 (11) |
[Co2(C8H18Sn2)(CO)6] | γ = 109.09 (2)° |
Mr = 637.52 | V = 1090.5 (6) Å3 |
Triclinic, P1 | Z = 2 |
a = 8.659 (4) Å | Ag Kα radiation, λ = 0.56083 Å |
b = 10.0360 (17) Å | µ = 1.98 mm−1 |
c = 13.292 (3) Å | T = 293 K |
α = 91.731 (16)° | 0.40 × 0.30 × 0.05 mm |
β = 91.17 (3)° |
Nonius CAD-4 diffractometer | 3813 reflections with I > 2σ(I) |
Absorption correction: ψ scan (WinGX; Farrugia, 1999; North et al., 1968) | Rint = 0.019 |
Tmin = 0.620, Tmax = 0.997 | 3 standard reflections every 60 min |
9426 measured reflections | intensity decay: none |
4713 independent reflections |
R[F2 > 2σ(F2)] = 0.034 | 0 restraints |
wR(F2) = 0.091 | H-atom parameters constrained |
S = 1.03 | Δρmax = 1.15 e Å−3 |
4713 reflections | Δρmin = −1.54 e Å−3 |
224 parameters |
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 | ||
Sn1 | 0.23433 (3) | 0.46053 (3) | 0.251823 (19) | 0.04642 (10) | |
Sn2 | 0.54726 (3) | 0.94962 (3) | 0.21592 (2) | 0.04575 (10) | |
Co1 | 0.09136 (6) | 0.76295 (5) | 0.17469 (4) | 0.04472 (14) | |
Co2 | 0.16469 (6) | 0.78922 (6) | 0.35914 (4) | 0.04702 (14) | |
O1 | 0.0671 (6) | 1.0421 (4) | 0.1399 (4) | 0.1016 (13) | |
O2 | −0.2450 (5) | 0.5692 (5) | 0.1871 (4) | 0.1063 (15) | |
O3 | 0.1587 (6) | 0.6853 (6) | −0.0283 (3) | 0.1123 (15) | |
O4 | −0.1387 (6) | 0.5951 (6) | 0.4359 (4) | 0.126 (2) | |
O5 | 0.1589 (6) | 1.0769 (4) | 0.3971 (3) | 0.1030 (14) | |
O6 | 0.3909 (6) | 0.7805 (5) | 0.5218 (3) | 0.1100 (16) | |
C1 | 0.0780 (6) | 0.9363 (5) | 0.1549 (3) | 0.0631 (11) | |
C2 | −0.1150 (5) | 0.6445 (5) | 0.1830 (3) | 0.0638 (11) | |
C3 | 0.1323 (6) | 0.7160 (5) | 0.0501 (3) | 0.0666 (11) | |
C4 | −0.0236 (7) | 0.6703 (6) | 0.4058 (4) | 0.0759 (14) | |
C5 | 0.1607 (6) | 0.9664 (5) | 0.3817 (3) | 0.0643 (11) | |
C6 | 0.3017 (6) | 0.7841 (5) | 0.4595 (3) | 0.0662 (12) | |
C7 | 0.2264 (4) | 0.6713 (4) | 0.2535 (3) | 0.0418 (7) | |
C8 | 0.3120 (4) | 0.8039 (4) | 0.2425 (3) | 0.0412 (7) | |
C9 | 0.4148 (6) | 0.4613 (6) | 0.3624 (4) | 0.0697 (12) | |
H9A | 0.5213 | 0.5099 | 0.3381 | 0.105* | |
H9B | 0.4066 | 0.3660 | 0.3762 | 0.105* | |
H9C | 0.3980 | 0.5085 | 0.4231 | 0.105* | |
C10 | 0.3025 (8) | 0.4188 (6) | 0.1041 (4) | 0.0757 (14) | |
H10A | 0.4168 | 0.4682 | 0.0965 | 0.114* | |
H10B | 0.2398 | 0.4500 | 0.0554 | 0.114* | |
H10C | 0.2815 | 0.3192 | 0.0938 | 0.114* | |
C11 | −0.0033 (6) | 0.3260 (5) | 0.2861 (4) | 0.0756 (14) | |
H11A | 0.0011 | 0.2343 | 0.3010 | 0.113* | |
H11B | −0.0765 | 0.3179 | 0.2293 | 0.113* | |
H11C | −0.0418 | 0.3650 | 0.3434 | 0.113* | |
C12 | 0.5244 (6) | 1.1542 (4) | 0.2171 (4) | 0.0655 (11) | |
H12A | 0.4192 | 1.1482 | 0.1890 | 0.098* | |
H12B | 0.6085 | 1.2150 | 0.1777 | 0.098* | |
H12C | 0.5351 | 1.1918 | 0.2851 | 0.098* | |
C13 | 0.7062 (6) | 0.9255 (6) | 0.3335 (4) | 0.0750 (13) | |
H13A | 0.6663 | 0.9439 | 0.3975 | 0.113* | |
H13B | 0.8141 | 0.9907 | 0.3255 | 0.113* | |
H13C | 0.7097 | 0.8308 | 0.3304 | 0.113* | |
C14 | 0.6169 (7) | 0.8873 (7) | 0.0737 (4) | 0.0803 (15) | |
H14A | 0.6323 | 0.7972 | 0.0786 | 0.120* | |
H14B | 0.7171 | 0.9561 | 0.0547 | 0.120* | |
H14C | 0.5326 | 0.8805 | 0.0239 | 0.120* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Sn1 | 0.04805 (17) | 0.04004 (15) | 0.05211 (17) | 0.01603 (11) | −0.00076 (11) | −0.00017 (10) |
Sn2 | 0.03709 (15) | 0.04657 (16) | 0.05209 (16) | 0.01188 (11) | 0.00044 (10) | 0.00039 (10) |
Co1 | 0.0395 (3) | 0.0487 (3) | 0.0464 (3) | 0.0152 (2) | −0.00260 (19) | 0.0017 (2) |
Co2 | 0.0472 (3) | 0.0536 (3) | 0.0437 (3) | 0.0215 (2) | 0.0020 (2) | −0.0023 (2) |
O1 | 0.120 (4) | 0.073 (2) | 0.127 (4) | 0.053 (3) | 0.000 (3) | 0.019 (2) |
O2 | 0.052 (2) | 0.123 (4) | 0.116 (3) | −0.008 (2) | 0.001 (2) | 0.009 (3) |
O3 | 0.129 (4) | 0.156 (4) | 0.054 (2) | 0.052 (3) | 0.002 (2) | −0.013 (2) |
O4 | 0.085 (3) | 0.158 (5) | 0.101 (3) | −0.010 (3) | 0.039 (3) | 0.016 (3) |
O5 | 0.136 (4) | 0.078 (3) | 0.113 (3) | 0.063 (3) | −0.021 (3) | −0.028 (2) |
O6 | 0.126 (4) | 0.160 (5) | 0.066 (2) | 0.082 (3) | −0.028 (2) | −0.009 (3) |
C1 | 0.058 (3) | 0.070 (3) | 0.067 (3) | 0.029 (2) | −0.008 (2) | 0.005 (2) |
C2 | 0.046 (2) | 0.075 (3) | 0.064 (3) | 0.012 (2) | −0.0060 (18) | 0.002 (2) |
C3 | 0.064 (3) | 0.088 (3) | 0.048 (2) | 0.026 (2) | −0.0059 (19) | −0.004 (2) |
C4 | 0.071 (3) | 0.094 (4) | 0.057 (3) | 0.020 (3) | 0.014 (2) | −0.003 (2) |
C5 | 0.067 (3) | 0.077 (3) | 0.060 (2) | 0.042 (2) | −0.007 (2) | −0.010 (2) |
C6 | 0.080 (3) | 0.083 (3) | 0.044 (2) | 0.040 (3) | −0.003 (2) | −0.0070 (19) |
C7 | 0.0419 (18) | 0.0432 (17) | 0.0431 (17) | 0.0182 (14) | 0.0008 (13) | −0.0003 (13) |
C8 | 0.0364 (16) | 0.0440 (17) | 0.0446 (18) | 0.0153 (14) | −0.0009 (13) | 0.0002 (14) |
C9 | 0.069 (3) | 0.078 (3) | 0.071 (3) | 0.038 (3) | −0.011 (2) | 0.001 (2) |
C10 | 0.096 (4) | 0.076 (3) | 0.063 (3) | 0.040 (3) | 0.008 (2) | −0.011 (2) |
C11 | 0.061 (3) | 0.057 (3) | 0.096 (4) | 0.002 (2) | 0.002 (2) | 0.010 (2) |
C12 | 0.064 (3) | 0.043 (2) | 0.086 (3) | 0.0130 (19) | −0.004 (2) | 0.000 (2) |
C13 | 0.055 (3) | 0.090 (3) | 0.080 (3) | 0.024 (2) | −0.017 (2) | 0.007 (3) |
C14 | 0.081 (4) | 0.101 (4) | 0.064 (3) | 0.038 (3) | 0.015 (3) | −0.007 (3) |
Sn1—C9 | 2.121 (5) | O4—C4 | 1.125 (6) |
Sn1—C11 | 2.127 (5) | O5—C5 | 1.127 (6) |
Sn1—C10 | 2.131 (5) | O6—C6 | 1.130 (6) |
Sn1—C7 | 2.138 (3) | C7—C8 | 1.309 (5) |
Sn2—C12 | 2.126 (4) | C9—H9A | 0.9600 |
Sn2—C8 | 2.127 (4) | C9—H9B | 0.9600 |
Sn2—C13 | 2.133 (5) | C9—H9C | 0.9600 |
Sn2—C14 | 2.133 (5) | C10—H10A | 0.9600 |
Co1—C3 | 1.781 (5) | C10—H10B | 0.9600 |
Co1—C2 | 1.801 (5) | C10—H10C | 0.9600 |
Co1—C1 | 1.808 (5) | C11—H11A | 0.9600 |
Co1—C7 | 2.006 (4) | C11—H11B | 0.9600 |
Co1—C8 | 2.006 (4) | C11—H11C | 0.9600 |
Co1—Co2 | 2.5043 (9) | C12—H12A | 0.9600 |
Co2—C6 | 1.780 (5) | C12—H12B | 0.9600 |
Co2—C5 | 1.806 (5) | C12—H12C | 0.9600 |
Co2—C4 | 1.811 (5) | C13—H13A | 0.9600 |
Co2—C7 | 2.000 (3) | C13—H13B | 0.9600 |
Co2—C8 | 2.007 (4) | C13—H13C | 0.9600 |
O1—C1 | 1.119 (6) | C14—H14A | 0.9600 |
O2—C2 | 1.136 (6) | C14—H14B | 0.9600 |
O3—C3 | 1.127 (6) | C14—H14C | 0.9600 |
C9—Sn1—C11 | 112.9 (2) | C8—C7—Co2 | 71.2 (2) |
C9—Sn1—C10 | 112.0 (2) | C8—C7—Co1 | 71.0 (2) |
C11—Sn1—C10 | 112.4 (2) | Co2—C7—Co1 | 77.38 (12) |
C9—Sn1—C7 | 105.74 (17) | C8—C7—Sn1 | 144.7 (3) |
C11—Sn1—C7 | 107.10 (18) | Co2—C7—Sn1 | 132.34 (18) |
C10—Sn1—C7 | 106.14 (17) | Co1—C7—Sn1 | 132.51 (18) |
C12—Sn2—C8 | 107.24 (17) | C7—C8—Co1 | 70.9 (2) |
C12—Sn2—C13 | 113.1 (2) | C7—C8—Co2 | 70.7 (2) |
C8—Sn2—C13 | 106.30 (17) | Co1—C8—Co2 | 77.22 (13) |
C12—Sn2—C14 | 113.0 (2) | C7—C8—Sn2 | 145.7 (3) |
C8—Sn2—C14 | 106.23 (19) | Co1—C8—Sn2 | 133.33 (18) |
C13—Sn2—C14 | 110.5 (2) | Co2—C8—Sn2 | 130.94 (17) |
C3—Co1—C2 | 99.2 (2) | Sn1—C9—H9A | 109.5 |
C3—Co1—C1 | 100.1 (2) | Sn1—C9—H9B | 109.5 |
C2—Co1—C1 | 106.8 (2) | H9A—C9—H9B | 109.5 |
C3—Co1—C7 | 99.67 (19) | Sn1—C9—H9C | 109.5 |
C2—Co1—C7 | 104.20 (19) | H9A—C9—H9C | 109.5 |
C1—Co1—C7 | 139.71 (18) | H9B—C9—H9C | 109.5 |
C3—Co1—C8 | 100.80 (19) | Sn1—C10—H10A | 109.5 |
C2—Co1—C8 | 139.81 (18) | Sn1—C10—H10B | 109.5 |
C1—Co1—C8 | 103.50 (18) | H10A—C10—H10B | 109.5 |
C7—Co1—C8 | 38.10 (14) | Sn1—C10—H10C | 109.5 |
C3—Co1—Co2 | 149.37 (16) | H10A—C10—H10C | 109.5 |
C2—Co1—Co2 | 97.65 (15) | H10B—C10—H10C | 109.5 |
C1—Co1—Co2 | 99.27 (15) | Sn1—C11—H11A | 109.5 |
C7—Co1—Co2 | 51.21 (10) | Sn1—C11—H11B | 109.5 |
C8—Co1—Co2 | 51.39 (10) | H11A—C11—H11B | 109.5 |
C6—Co2—C5 | 99.0 (2) | Sn1—C11—H11C | 109.5 |
C6—Co2—C4 | 99.5 (2) | H11A—C11—H11C | 109.5 |
C5—Co2—C4 | 107.0 (3) | H11B—C11—H11C | 109.5 |
C6—Co2—C7 | 100.43 (18) | Sn2—C12—H12A | 109.5 |
C5—Co2—C7 | 140.47 (19) | Sn2—C12—H12B | 109.5 |
C4—Co2—C7 | 103.3 (2) | H12A—C12—H12B | 109.5 |
C6—Co2—C8 | 99.72 (19) | Sn2—C12—H12C | 109.5 |
C5—Co2—C8 | 104.60 (19) | H12A—C12—H12C | 109.5 |
C4—Co2—C8 | 139.60 (19) | H12B—C12—H12C | 109.5 |
C7—Co2—C8 | 38.15 (14) | Sn2—C13—H13A | 109.5 |
C6—Co2—Co1 | 149.34 (15) | Sn2—C13—H13B | 109.5 |
C5—Co2—Co1 | 98.63 (15) | H13A—C13—H13B | 109.5 |
C4—Co2—Co1 | 99.08 (17) | Sn2—C13—H13C | 109.5 |
C7—Co2—Co1 | 51.41 (10) | H13A—C13—H13C | 109.5 |
C8—Co2—Co1 | 51.39 (10) | H13B—C13—H13C | 109.5 |
O1—C1—Co1 | 177.9 (5) | Sn2—C14—H14A | 109.5 |
O2—C2—Co1 | 179.2 (5) | Sn2—C14—H14B | 109.5 |
O3—C3—Co1 | 179.3 (5) | H14A—C14—H14B | 109.5 |
O4—C4—Co2 | 178.6 (6) | Sn2—C14—H14C | 109.5 |
O5—C5—Co2 | 179.0 (4) | H14A—C14—H14C | 109.5 |
O6—C6—Co2 | 178.6 (5) | H14B—C14—H14C | 109.5 |
C3—Co1—Co2—C6 | 6.1 (5) | C11—Sn1—C7—C8 | 179.0 (5) |
C2—Co1—Co2—C6 | 129.0 (4) | C10—Sn1—C7—C8 | −60.8 (5) |
C1—Co1—Co2—C6 | −122.5 (4) | C9—Sn1—C7—Co2 | −63.9 (3) |
C7—Co1—Co2—C6 | 26.9 (4) | C11—Sn1—C7—Co2 | 56.7 (3) |
C8—Co1—Co2—C6 | −22.5 (4) | C10—Sn1—C7—Co2 | 177.0 (3) |
C3—Co1—Co2—C5 | 130.5 (4) | C9—Sn1—C7—Co1 | −179.6 (2) |
C2—Co1—Co2—C5 | −106.6 (2) | C11—Sn1—C7—Co1 | −59.0 (3) |
C1—Co1—Co2—C5 | 1.9 (2) | C10—Sn1—C7—Co1 | 61.3 (3) |
C7—Co1—Co2—C5 | 151.3 (2) | Co2—C7—C8—Co1 | −82.72 (10) |
C8—Co1—Co2—C5 | 101.8 (2) | Sn1—C7—C8—Co1 | 138.6 (4) |
C3—Co1—Co2—C4 | −120.6 (4) | Co1—C7—C8—Co2 | 82.72 (10) |
C2—Co1—Co2—C4 | 2.3 (2) | Sn1—C7—C8—Co2 | −138.6 (4) |
C1—Co1—Co2—C4 | 110.8 (3) | Co2—C7—C8—Sn2 | 135.9 (5) |
C7—Co1—Co2—C4 | −99.8 (2) | Co1—C7—C8—Sn2 | −141.4 (5) |
C8—Co1—Co2—C4 | −149.2 (2) | Sn1—C7—C8—Sn2 | −2.8 (8) |
C3—Co1—Co2—C7 | −20.8 (3) | C3—Co1—C8—C7 | −91.9 (3) |
C2—Co1—Co2—C7 | 102.1 (2) | C2—Co1—C8—C7 | 26.6 (4) |
C1—Co1—Co2—C7 | −149.4 (2) | C1—Co1—C8—C7 | 164.9 (3) |
C8—Co1—Co2—C7 | −49.44 (18) | Co2—Co1—C8—C7 | 73.7 (2) |
C3—Co1—Co2—C8 | 28.6 (4) | C3—Co1—C8—Co2 | −165.62 (18) |
C2—Co1—Co2—C8 | 151.5 (2) | C2—Co1—C8—Co2 | −47.1 (3) |
C1—Co1—Co2—C8 | −99.9 (2) | C1—Co1—C8—Co2 | 91.17 (18) |
C7—Co1—Co2—C8 | 49.44 (18) | C7—Co1—C8—Co2 | −73.7 (2) |
C6—Co2—C7—C8 | −92.5 (3) | C3—Co1—C8—Sn2 | 59.2 (3) |
C5—Co2—C7—C8 | 25.7 (4) | C2—Co1—C8—Sn2 | 177.7 (3) |
C4—Co2—C7—C8 | 165.0 (3) | C1—Co1—C8—Sn2 | −44.1 (3) |
Co1—Co2—C7—C8 | 73.9 (2) | C7—Co1—C8—Sn2 | 151.1 (4) |
C6—Co2—C7—Co1 | −166.43 (19) | Co2—Co1—C8—Sn2 | −135.2 (3) |
C5—Co2—C7—Co1 | −48.3 (3) | C6—Co2—C8—C7 | 94.6 (3) |
C4—Co2—C7—Co1 | 91.1 (2) | C5—Co2—C8—C7 | −163.5 (2) |
C8—Co2—C7—Co1 | −73.9 (2) | C4—Co2—C8—C7 | −22.8 (4) |
C6—Co2—C7—Sn1 | 56.4 (3) | Co1—Co2—C8—C7 | −74.0 (2) |
C5—Co2—C7—Sn1 | 174.6 (3) | C6—Co2—C8—Co1 | 168.56 (18) |
C4—Co2—C7—Sn1 | −46.0 (3) | C5—Co2—C8—Co1 | −89.44 (17) |
C8—Co2—C7—Sn1 | 148.9 (4) | C4—Co2—C8—Co1 | 51.2 (4) |
Co1—Co2—C7—Sn1 | −137.1 (3) | C7—Co2—C8—Co1 | 74.0 (2) |
C3—Co1—C7—C8 | 95.2 (3) | C6—Co2—C8—Sn2 | −54.1 (3) |
C2—Co1—C7—C8 | −162.6 (2) | C5—Co2—C8—Sn2 | 47.9 (3) |
C1—Co1—C7—C8 | −23.1 (4) | C4—Co2—C8—Sn2 | −171.5 (3) |
Co2—Co1—C7—C8 | −74.2 (2) | C7—Co2—C8—Sn2 | −148.7 (4) |
C3—Co1—C7—Co2 | 169.41 (18) | Co1—Co2—C8—Sn2 | 137.3 (3) |
C2—Co1—C7—Co2 | −88.44 (18) | C12—Sn2—C8—C7 | −179.1 (5) |
C1—Co1—C7—Co2 | 51.1 (3) | C13—Sn2—C8—C7 | −57.9 (5) |
C8—Co1—C7—Co2 | 74.2 (2) | C14—Sn2—C8—C7 | 59.8 (5) |
C3—Co1—C7—Sn1 | −53.6 (3) | C12—Sn2—C8—Co1 | 55.0 (3) |
C2—Co1—C7—Sn1 | 48.5 (3) | C13—Sn2—C8—Co1 | 176.3 (3) |
C1—Co1—C7—Sn1 | −172.0 (3) | C14—Sn2—C8—Co1 | −66.0 (3) |
C8—Co1—C7—Sn1 | −148.8 (4) | C12—Sn2—C8—Co2 | −59.5 (3) |
Co2—Co1—C7—Sn1 | 137.0 (3) | C13—Sn2—C8—Co2 | 61.7 (3) |
C9—Sn1—C7—C8 | 58.3 (5) | C14—Sn2—C8—Co2 | 179.4 (3) |
Experimental details
Crystal data | |
Chemical formula | [Co2(C8H18Sn2)(CO)6] |
Mr | 637.52 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 293 |
a, b, c (Å) | 8.659 (4), 10.0360 (17), 13.292 (3) |
α, β, γ (°) | 91.731 (16), 91.17 (3), 109.09 (2) |
V (Å3) | 1090.5 (6) |
Z | 2 |
Radiation type | Ag Kα, λ = 0.56083 Å |
µ (mm−1) | 1.98 |
Crystal size (mm) | 0.40 × 0.30 × 0.05 |
Data collection | |
Diffractometer | Nonius CAD-4 |
Absorption correction | ψ scan (WinGX; Farrugia, 1999; North et al., 1968) |
Tmin, Tmax | 0.620, 0.997 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 9426, 4713, 3813 |
Rint | 0.019 |
(sin θ/λ)max (Å−1) | 0.639 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.034, 0.091, 1.03 |
No. of reflections | 4713 |
No. of parameters | 224 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 1.15, −1.54 |
Computer programs: CAD4 Version 5.0 (Nonius, 1989), XCAD4 (Harms, 1996), SHELXS97 (Sheldrick, 1990), SHELXTL-Plus (Sheldrick, 1991), SHELXL97 (Sheldrick, 1997), PARST95 (Nardelli, 1995).
The title compound (I) was prepared thirty years ago, but the nature of the bonding in the crystal remained unknown until now. The tin–carbon bond in stannyl alkynes is relatively labile, though these can be used in Stille-type palladium-catalysed cross-coupling reactions with organyl halides (Mitchell, 1998). However, the reactivity of the carbon–carbon triple bond is such that oligomeric and polymeric side-products are obtained in large amounts. Complexation of the carbon–carbon triple bond by the dicobalt hexacarbonyl moiety to give a dicobaltatetrahedrane structure does not hinder cross-coupling with activated organyl halides (Zavgorodnii et al., 2000). The title compound is air- and moisture-insensitive, whereas the uncomplexed bis(trimethylstannyl)acetylene is easily hydrolysed by atmospheric moisture.
Only one dicobaltatetrahedrane derived from a stannyl alkyne has so far been studied by X-ray crystallography (Wrackmeyer et al., 1997) but this compound (A) could be atypical for steric reasons, as it is prepared by reacting diphenyldiethynyltin Ph2Sn(C≡CH)2 with dicobalt octacarbonyl, both acetylenic bonds being converted to dicobaltatetrahedrane moieties.
The structure of (I) is shown in Fig. 1. The length of the complexed acetylenic triple bond in this structure is 1.309 (5) Å, as compared with 1.238 Å in the uncomplexed stannyl acetylene and 1.212 (1) Å in acetylene itself (Khaikin et al., 2000); it is markedly shorter than in (A) [1.322 (9) and 1.335 (9) Å]. The cobalt–cobalt distance (2.5043 (9) Å) is considerably longer than in (A) [2.4788 (2) and 2.487 (2) Å]. While in (A) the cobalt–carbon bond lengths in the dicobaltatetrahedrane moiety lie between 1.944 and 1.990 Å (the authors describe these as "normal" values), all four Co—C bonds in the title compound are equal or longer than 2.000 Å (up to 2.007 Å). The originally linear Sn—C—C—Sn arrangement is naturally considerably bent, the angles Sn—C—C being 144.7 (3)° and 145.7 (3)°; in (A), however, the bond angles are much larger at 150.5 (5) and 151.5 (5)°.