journal menu
research papers
The experimental electron density (ED) of the triclinic phase of Co2(CO)6(μ-CO)(μ-C4O2H2), μ-carbonyl-μ-5-oxo-2,5-dihydrofuran-2-ylbis(tricarbonylcobalt), has been determined through X-ray diffraction at 120 K. The presence of a `closed shell' Co—Co bond in the title compound, found in an experimental ED study of its orthorhombic form, is confirmed by the Quantum Theory of Atoms in Molecules. However, the two phases show a significant Co—Co bond length difference [triclinic: 2.4402 (2) Å; orthorhombic: 2.4222 (3) Å]. The flat distribution of the experimental ED along the Co—Co bond path and on the two Co2C rings allows for variations of the Co—Co bond length which may be easily induced by the different packing arrangements of the two forms.
Supporting information
 | Crystallographic Information File (CIF) https://doi.org/10.1107/S0108768101009028/lc0036sup1.cif |
 | Structure factor file (CIF format) https://doi.org/10.1107/S0108768101009028/lc0036sup2.hkl |
 | Portable Document Format (PDF) file https://doi.org/10.1107/S0108768101009028/lc0036sup3.pdf |
CCDC reference: 174972
Computing details top
Data collection: Siemens XSCANS; cell refinement: Siemens XSCANS; data reduction: REFPK,BGLP,TSCALE,SORTAV; program(s) used to refine structure: VALRAY.
![[Figure 1]](http://journals.iucr.org/b/issues/2001/05/00/lc0036/lc0036fig1thm.gif)
![[Figure 2]](http://journals.iucr.org/b/issues/2001/05/00/lc0036/lc0036fig2thm.gif)
![[Figure 3]](http://journals.iucr.org/b/issues/2001/05/00/lc0036/lc0036fig3thm.gif)
![[Figure 4]](http://journals.iucr.org/b/issues/2001/05/00/lc0036/lc0036fig4thm.gif)
![[Figure 5]](http://journals.iucr.org/b/issues/2001/05/00/lc0036/lc0036fig5thm.gif)
(COMPLEX3) top
Crystal data top
| C11H2Co2O9 | Z = 2 |
| Mr = 395.99 | F(000) = 388 |
| Triclinic, P1 | Dx = 1.942 Mg m−3 |
| a = 7.169 (2) Å | Mo Kα radiation, λ = 0.71073 Å |
| b = 8.452 (2) Å | Cell parameters from 35 reflections |
| c = 11.364 (3) Å | θ = 10–15° |
| α = 82.77 (1)° | µ = 2.49 mm−1 |
| β = 80.84 (1)° | T = 120 K |
| γ = 87.72 (2)° | Prismatic, red |
| V = 674.3 (3) Å3 | 0.40 × 0.36 × 0.24 mm |
Data collection top
| Siemens P4 diffractometer | 5479 reflections with > 3σ(I) |
| Radiation source: fine-focus sealed tube | Rint = 0.034 |
| Graphite monochromator | θmax = 48.5°, θmin = 1° |
| θ/2θ scans | h = −15→10 |
| Absorption correction: numerical (De Titta, 1985) | k = −19→19 |
| Tmin = 0.373, Tmax = 0.601 | l = −26→21 |
| 35370 measured reflections | 7 standard reflections every 50 reflections |
| 11623 independent reflections | intensity decay: none |
Refinement top
| 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)] = 0.024 | H atoms treated by a mixture of independent and constrained refinement |
| wR(F2) = 0.030 | 1/s2 |
| S = 0.87 | (Δ/σ)max = 0.01 |
| 5479 reflections | Δρmax = 0.4 e Å−3 |
| 571 parameters | Δρmin = −0.1 e Å−3 |
Crystal data top
| C11H2Co2O9 | γ = 87.72 (2)° |
| Mr = 395.99 | V = 674.3 (3) Å3 |
| Triclinic, P1 | Z = 2 |
| a = 7.169 (2) Å | Mo Kα radiation |
| b = 8.452 (2) Å | µ = 2.49 mm−1 |
| c = 11.364 (3) Å | T = 120 K |
| α = 82.77 (1)° | 0.40 × 0.36 × 0.24 mm |
| β = 80.84 (1)° |
Data collection top
| Siemens P4 diffractometer | 5479 reflections with > 3σ(I) |
| Absorption correction: numerical (De Titta, 1985) | Rint = 0.034 |
| Tmin = 0.373, Tmax = 0.601 | 7 standard reflections every 50 reflections |
| 35370 measured reflections | intensity decay: none |
| 11623 independent reflections |
Refinement top
| R[F2 > 2σ(F2)] = 0.024 | 571 parameters |
| wR(F2) = 0.030 | H atoms treated by a mixture of independent and constrained refinement |
| S = 0.87 | Δρmax = 0.4 e Å−3 |
| 5479 reflections | Δρmin = −0.1 e Å−3 |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
| x | y | z | Uiso*/Ueq | ||
| Co1 | 0.28425 (2) | 0.76609 (2) | 0.32153 (1) | 0.015 (1) | |
| Co2 | 0.30481 (2) | 0.50598 (2) | 0.24783 (1) | 0.016 (1) | |
| C1' | 0.1428 (1) | 0.9455 (2) | 0.2960 (2) | 0.016 (1) | |
| O1' | 0.0524 (5) | 1.0573 (3) | 0.2786 (3) | 0.028 (1) | |
| C2' | 0.2674 (3) | 0.7492 (2) | 0.4849 (2) | 0.025 (1) | |
| O2' | 0.2580 (6) | 0.7451 (4) | 0.5859 (3) | 0.036 (1) | |
| C3' | 0.5334 (3) | 0.8308 (2) | 0.2928 (2) | 0.015 (1) | |
| O3' | 0.6863 (5) | 0.8675 (4) | 0.2745 (3) | 0.031 (1) | |
| C4 | 0.0926 (3) | 0.6049 (2) | 0.3399 (2) | 0.013 (1) | |
| O4 | −0.0634 (4) | 0.5813 (3) | 0.3835 (2) | 0.018 (1) | |
| C5' | 0.1920 (3) | 0.4160 (2) | 0.1417 (2) | 0.016 (1) | |
| O5' | 0.1221 (4) | 0.3627 (3) | 0.0731 (3) | 0.025 (1) | |
| C6' | 0.2969 (3) | 0.3360 (2) | 0.3647 (2) | 0.026 (1) | |
| O6' | 0.2941 (5) | 0.2271 (3) | 0.4342 (3) | 0.033 (1) | |
| C7' | 0.5637 (3) | 0.4857 (2) | 0.2027 (2) | 0.020 (1) | |
| O7' | 0.7225 (5) | 0.4757 (4) | 0.1760 (3) | 0.035 (1) | |
| C6 | 0.3065 (3) | 0.7203 (2) | 0.1524 (2) | 0.011 (1) | |
| C7 | 0.4238 (4) | 0.8359 (2) | −0.0360 (2) | 0.012 (1) | |
| C8 | 0.2176 (3) | 0.8406 (2) | −0.0236 (2) | 0.017 (1) | |
| C9 | 0.1494 (3) | 0.7704 (2) | 0.0871 (2) | 0.022 (1) | |
| O6 | 0.4713 (3) | 0.7632 (2) | 0.0714 (2) | 0.014 (1) | |
| O7 | 0.5441 (5) | 0.8800 (3) | −0.1194 (3) | 0.022 (1) | |
| H8 | 0.148 (4) | 0.885 (3) | −0.093 (3) | 0.04 (1)* | |
| H9 | 0.006 (5) | 0.756 (3) | 0.124 (2) | 0.05 (1)* |
Atomic displacement parameters (Å2) top
| U11 | U22 | U33 | U12 | U13 | U23 | |
| Co1 | 0.0166 (2) | 0.0152 (2) | 0.0159 (2) | −0.0008 (1) | −0.0023 (1) | −0.00204 (9) |
| Co2 | 0.0166 (2) | 0.0152 (2) | 0.0165 (2) | −0.00031 (9) | −0.0024 (1) | −0.00064 (9) |
| C1' | 0.020 (1) | 0.0163 (7) | 0.0289 (8) | 0.0009 (6) | −0.0034 (7) | −0.0029 (6) |
| O1' | 0.027 (1) | 0.021 (1) | 0.046 (1) | 0.006 (1) | −0.007 (1) | −0.004 (1) |
| C2' | 0.028 (1) | 0.0263 (8) | 0.0191 (8) | −0.0027 (7) | −0.0049 (7) | −0.0045 (7) |
| O2' | 0.048 (2) | 0.049 (1) | 0.017 (1) | −0.001 (1) | −0.005 (1) | −0.006 (1) |
| C3' | 0.019 (1) | 0.0256 (7) | 0.0239 (8) | −0.0039 (7) | −0.0063 (7) | 0.0001 (6) |
| O3' | 0.023 (1) | 0.040 (1) | 0.039 (1) | −0.009 (1) | −0.007 (1) | 0.005 (1) |
| C4 | 0.018 (1) | 0.0208 (6) | 0.0162 (7) | −0.0025 (6) | −0.0012 (6) | −0.0008 (5) |
| O4 | 0.020 (1) | 0.028 (1) | 0.028 (1) | −0.003 (1) | −0.001 (1) | −0.0011 (9) |
| C5' | 0.021 (1) | 0.0201 (6) | 0.0209 (7) | −0.0029 (6) | −0.0060 (6) | −0.0033 (6) |
| O5' | 0.027 (1) | 0.029 (1) | 0.031 (1) | −0.003 (1) | −0.011 (1) | −0.0069 (9) |
| C6' | 0.027 (1) | 0.0184 (7) | 0.0204 (8) | 0.014 (7) | −0.0040 (7) | 0.0004 (6) |
| O6' | 0.048 (1) | 0.021 (1) | 0.030 (1) | 0.001 (1) | −0.006 (1) | 0.0091 (9) |
| C7' | 0.020 (1) | 0.0218 (7) | 0.0230 (8) | 0.0017 (7) | −0.0021 (7) | −0.0021 (7) |
| O7' | 0.018 (1) | 0.040 (1) | 0.038 (1) | 0.006 (1) | −0.001 (1) | −0.001 (1) |
| C6 | 0.020 (1) | 0.0156 (6) | 0.0163 (7) | −0.0017 (6) | −0.0029 (6) | 0.0006 (5) |
| C7 | 0.025 (1) | 0.0177 (6) | 0.0177 (8) | 0.0002 (6) | −0.0028 (7) | 0.0015 (6) |
| C8 | 0.025 (1) | 0.0206 (7) | 0.0193 (8) | −0.0008 (7) | −0.0072 (7) | 0.0016 (6) |
| C9 | 0.019 (1) | 0.0195 (6) | 0.0190 (7) | −0.0015 (6) | −0.0052 (7) | 0.0009 (6) |
| O6 | 0.019 (1) | 0.0185 (8) | 0.0176 (8) | 0.0002 (7) | −0.0024 (8) | 0.0018 (7) |
| O7 | 0.030 (1) | 0.0240 (9) | 0.023 (1) | 0.000 (1) | 0.002 (1) | 0.0069 (8) |
Geometric parameters (Å, º) top
| Co2—Co1 | 2.4402 (2) | O3'—C3' | 1.131 (4) |
| Co2—C4 | 1.929 (2) | O4—C4 | 1.163 (3) |
| Co2—C5' | 1.811 (2) | O5'—C5' | 1.137 (4) |
| Co2—C6 | 1.990 (2) | O6—C6 | 1.406 (3) |
| Co2—C6' | 1.825 (3) | O6—C7 | 1.382 (3) |
| Co2—C7' | 1.852 (2) | O6'—C6' | 1.134 (3) |
| Co1—C1' | 1.809 (2) | O7—C7 | 1.207 (4) |
| Co1—C2' | 1.829 (2) | O7'—C7' | 1.133 (4) |
| Co1—C3' | 1.856 (2) | C6—C9 | 1.465 (3) |
| Co1—C4 | 1.943 (2) | C7—C8 | 1.462 (4) |
| Co1—C6 | 1.989 (2) | C8—C9 | 1.346 (3) |
| O1'—C1' | 1.139 (3) | C8—H8 | 1.03 (3) |
| O2'—C2' | 1.135 (4) | C9—H9 | 1.05 (3) |
| Co2—Co1—C1' | 134.48 (7) | Co1—C3'—O3' | 178.7 (3) |
| Co2—Co1—C2' | 112.23 (6) | Co1—C4—O4 | 140.7 (2) |
| Co2—Co1—C3' | 103.16 (6) | Co2—C4—O4 | 141.2 (2) |
| Co2—Co1—C4 | 50.68 (5) | Co2—C5'—O5' | 178.4 (2) |
| Co2—Co1—C6 | 52.20 (4) | Co2—C6'—O6' | 177.6 (2) |
| Co1—Co2—C4 | 51.18 (6) | Co2—C7'—O7' | 178.7 (2) |
| Co1—Co2—C5' | 134.98 (6) | O6—C6—C9 | 105.5 (2) |
| Co1—Co2—C6 | 52.15 (5) | C6—O6—C7 | 109.9 (2) |
| Co1—Co2—C6' | 114.64 (6) | O6—C7—O7 | 121.1 (3) |
| Co1—Co2—C7' | 100.46 (6) | O6—C7—C8 | 107.4 (2) |
| Co1—C4—Co2 | 78.14 (7) | C7—C8—C9 | 107.8 (2) |
| Co1—C6—Co2 | 75.65 (6) | C6—C9—C8 | 109.5 (2) |
| Co1—C1'—O1' | 178.9 (3) | C7—C8—H8 | 122 (2) |
| Co1—C2'—O2' | 177.3 (2) | C8—C9—H9 | 127 (1) |
Experimental details
| Crystal data | |
| Chemical formula | C11H2Co2O9 |
| Mr | 395.99 |
| Crystal system, space group | Triclinic, P1 |
| Temperature (K) | 120 |
| a, b, c (Å) | 7.169 (2), 8.452 (2), 11.364 (3) |
| α, β, γ (°) | 82.77 (1), 80.84 (1), 87.72 (2) |
| V (Å3) | 674.3 (3) |
| Z | 2 |
| Radiation type | Mo Kα |
| µ (mm−1) | 2.49 |
| Crystal size (mm) | 0.40 × 0.36 × 0.24 |
| Data collection | |
| Diffractometer | Siemens P4 diffractometer |
| Absorption correction | Numerical (De Titta, 1985) |
| Tmin, Tmax | 0.373, 0.601 |
| No. of measured, independent and observed [ > 3σ(I)] reflections | 35370, 11623, 5479 |
| Rint | 0.034 |
| (sin θ/λ)max (Å−1) | 1.054 |
| Refinement | |
| R[F2 > 2σ(F2)], wR(F2), S | 0.024, 0.030, 0.87 |
| No. of reflections | 5479 |
| No. of parameters | 571 |
| No. of restraints | ? |
| H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
| Δρmax, Δρmin (e Å−3) | 0.4, −0.1 |
Computer programs: Siemens XSCANS, REFPK,BGLP,TSCALE,SORTAV, VALRAY.
The present EED study of the triclinic form of Co2(CO)6(µ-CO)(µ-C4O2H2) confirms the presence of a cobalt-cobalt bond in a system with bridging ligands in a folded Co2C2 moiety, as already found in the topological analysis of its orthorhombic form. The flat electron density around the Co—Co BCP and Co2C ring critical points is a peculiar feature of the metal-metal bond in the title compound. The values of the EED, its Laplacian, Gb, Vb and Eeb parameters observed for the "closed shell" Co—Co and Co—C(CO) bonds and for the intermolecular interactions agree with the bonding classification given in a previous paper. This analysis confirms the ability of the POP model to reproduce the weak O···O, O···C and O···H interactions, also when heavy atoms are present in the crystal structure.