Triruthenium dodecacarbonyl

Triruthenium dodecacarbonyl is the chemical compound with the formula Ru₃(CO)₁₂. Classified as metal carbonyl cluster, it is a dark orange-colored solid that is soluble in nonpolar organic solvents. The compound serves as a precursor to other organoruthenium compounds.

Triruthenium dodecacarbonyl

Names
IUPAC name cyclo-tris(tetracarbonylruthenium)(3 Ru—Ru)
Other names Ruthenium carbonyl
Identifiers
CAS Number	15243-33-1 Y
3D model (JSmol)	Interactive image
ChemSpider	24589240
ECHA InfoCard	100.035.701
EC Number	239-287-4
PubChem CID	6096991
CompTox Dashboard (EPA)	DTXSID901015348
InChI InChI=1S/12CO.3Ru/c12*1-2;;; Key: NQZFAUXPNWSLBI-UHFFFAOYSA-N
SMILES [Ru-4]1(C#[O+])(C#[O+])(C#[O+])(C#[O+])[Ru-4](C#[O+])(C#[O+])(C#[O+])(C#[O+])[Ru-4]1(C#[O+])(C#[O+])(C#[O+])(C#[O+])
Properties
Chemical formula	C12O12Ru3
Molar mass	639.33 g/mol
Appearance	orange solid
Density	2.48 g/cm3
Melting point	224 °C (435 °F; 497 K)
Boiling point	sublimes in vacuum
Solubility in water	insoluble
Solubility in organic solvents	soluble
Structure
Molecular shape	D3h cluster
Dipole moment	0 D
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	Toxic, CO Source
GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H302, H315, H319, H332, H335
Precautionary statements	P261, P264, P270, P271, P280, P301+P312, P302+P352, P304+P312, P304+P340, P305+P351+P338, P312, P321, P330, P332+P313, P337+P313, P362, P403+P233, P405, P501
Related compounds
Related compounds	Triiron dodecacarbonyl Triosmium dodecacarbonyl
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Structure and synthesis

The cluster has D_3h symmetry, consisting of an equilateral triangle of Ru atoms, each of which bears two axial and two equatorial CO ligands. The Ru-Ru distance is 284 pm.^[1] Os₃(CO)₁₂ has the same structure. In Fe₃(CO)₁₂, two CO ligands are bridging, resulting in C_2v symmetry. In solution, Ru₃(CO)₁₂ is fluxional as indicated by the observation of a single CO signal in the room temperature ¹³C NMR spectrum. The barrier is estimated at 20 kJ/mol^[2]

Ru₃(CO)₁₂ is prepared by treating solutions of ruthenium trichloride with carbon monoxide in the presence of a base. Dichlororuthenium tricarbonyl dimer is an intermediate.^[3][4] The stoichiometry of the reaction is uncertain, one possibility being the following:

6 RuCl₃ + 33 CO + 18 CH₃OH → 2 Ru₃(CO)₁₂ + 9 CO(OCH₃)₂ + 18 HCl

Reactions

The chemical properties of Ru₃(CO)₁₂ have been widely studied, and the cluster has been converted to hundreds of derivatives. High pressures of CO convert the cluster to the monomeric ruthenium pentacarbonyl, which reverts to the parent cluster upon standing.

Ru₃(CO)₁₂ + 3 CO ⇌ 3 Ru(CO)₅ K_eq = 3.3 x 10⁻⁷ mol dm⁻³ at room temperature

The instability of Ru(CO)₅ contrasts with the robustness of the corresponding Fe(CO)₅. The condensation of Ru(CO)₅ into Ru₃(CO)₁₂ proceeds via initial, rate-limiting loss of CO to give the unstable, coordinatively unsaturated species Ru(CO)₄. This tetracarbonyl binds Ru(CO)₅, initiating the condensation.^[5]

Upon warming under a pressure of hydrogen, Ru₃(CO)₁₂ converts to the tetrahedral cluster H₄Ru₄(CO)₁₂.^[6] Ru₃(CO)₁₂ undergoes substitution reactions with Lewis bases:

Ru₃(CO)₁₂ + n L → Ru₃(CO)_12-nL_n + n CO (n = 1, 2, or 3)

where L is a tertiary phosphine or an isocyanide. It forms complexes with acenaphthylene.^[7]

Ru₃(CO)₁₂ forms a variety of alkene complexes, some where the Ru3 core remains intact but often with fragmentation. Upon treatment with 1,5-cyclooctadiene gives the monoRu tricarbonyl derivative:^[8]

Ru₃(CO)₁₂ + 3 C₈H₁₂ → 3 Ru(C₈H₁₂)(CO)₃ + 3 CO

Upon irradiation with UV light, Ru₃(CO)₁₂ converts to an insoluble polymeric form.^[9]

Ru-carbido clusters

At high temperatures, Ru₃(CO)₁₂ converts to a series of clusters that contain interstitial carbido ligands. These include Ru₆C(CO)₁₇ and Ru₅C(CO)₁₅. Anionic carbido clusters are also known, including [Ru₅C(CO)₁₄]²⁻ and the bioctahedral cluster [Ru₁₀C₂(CO)₂₄]²⁻.^[10] Ru₃(CO)₁₂ -derived carbido compounds have been used to synthesize nanoparticles for catalysis. These particles consist of 6-7 atoms and thus are all surface, resulting in extraordinary activity.

References

1. Slebodnick, C.; Zhao, J.; Angel, R.; Hanson, B. E.; Song, Y.; Liu, Z.; Hemley, R. J. (2004). "High Pressure Study of Ru₃(CO)₁₂ by X-ray Diffraction, Raman, and Infrared Spectroscopy". Inorg. Chem. 43 (17): 5245–5252. doi:10.1021/ic049617y. PMID 15310201.
2. Farrugia, Louis J. (1997). "Dynamics and fluxionality in metal carbonyl clusters: Some old and new problems". Journal of the Chemical Society, Dalton Transactions (11): 1783–1792. doi:10.1039/A608514H.
3. Bruce, M. I.; Jensen, C. M.; Jones, N. L. (1989). "Polynuclear Ruthenium Complexes". Inorganic Syntheses. Vol. 26. pp. 259–61. doi:10.1002/9780470132579.ch45. ISBN 978-0-471-50485-6.
4. Fauré, Matthieu; Saccavini, Catherine; Lavigne, Guy (2004). "Transition Metal Carbonyl Compounds". Inorganic Syntheses. Vol. 34. p. 110. doi:10.1002/0471653683.ch3. ISBN 978-0-471-64750-8.
5. Hastings, W. R.; Roussel, M. R.; Baird, M. C. "Mechanism of the conversion of [Ru(CO)₅] into [Ru₃(CO)₁₂]" Journal of the Chemical Society, Dalton Transactions, 1990, pages 203-205. doi:10.1039/DT9900000203
6. Bruce, M. I.; Williams, M. L. "Dodecacarbonyl(tetrahydrido)tetraruthenium, Ru₄(μ-H)₄(CO)₁₂" Inorganic Syntheses, 1989, volume 26, pages 262-63. ISBN 0-471-50485-8.
7. Motoyama, Yukihiro; Itonaga, Chikara; Ishida, Toshiki; Takasaki, Mikihiro; Nagashima, Hideo (2005). "Catalytic Reduction of Amides to Amines with Hydrosilanes Using a Triruthenium Cluster as the Catalyst". Organic Syntheses. 82. 188. doi:10.15227/orgsyn.082.0188.
8. Domingos, A. J. P.; Howell, J. A. S.; Johnson, B. F. G.; Lewis, J. (1990). "Reagents for the Synthesis of η-Diene Complexes of Tricarbonnyliron and Tricarbonylruthenium". Inorganic Syntheses. Vol. 28. pp. 52–55. doi:10.1002/9780470132593.ch11. ISBN 978-0-471-52619-3.
9. Hastings, W. Ross; Baird, Michael C. (1986). "A new form of ruthenium tetracarbonyl". Inorganic Chemistry. 25 (16): 2913–2915. doi:10.1021/ic00236a054.
10. Nicholls, J. N.; Vargas, M. D. "Carbido-Carbonyl Ruthenium Cluster Complexes" Inorganic Syntheses, 1989, volume 26, pages 280-85. doi:10.1002/9780470132579.ch49