Methylidynetricobaltnonacarbonyl

Methylidynetricobaltnonacarbonyl
Names
	Other names methylidyne-tris(tricarbonylcobalt)
Identifiers
CAS Number	15664-75-2;
3D model (JSmol)	Interactive image;
PubChem CID	519159 wrong formula;
	InChI InChI=1S/9CO.CH.3Co/c91-2;;;;/h;;;;;;;;;1H;;;/q9+1;;3*-3 Key: WPOHNFRRRVAWSE-UHFFFAOYSA-N;
	SMILES [O+]#C[Co-3]12(C#[O+])(C#[O+])[Co-3]3(C#[O+])(C#[O+])(C#[O+])[Co-3]1(C#[O+])(C#[O+])(C#[O+])C23;
Properties
Chemical formula	C10HCo3O9
Molar mass	441.909 g·mol−1
Appearance	purple solid
Density	2.01 g/cm3
Melting point	105–107 °C (221–225 °F; 378–380 K)
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Methylidynetricobaltnonacarbonyl is the organocobalt compound with the formula HCCo₃(CO)₉. It is a metal carbonyl cluster that contains the methylidyne ligand. The compound has C_3v point group symmetry. It is a purple, air-stable solid that is soluble in some organic solvents, but not in water.

The compound is prepared by the reaction of dicobalt octacarbonyl with bromoform. Much of the cobalt(0) is consumed in the formation of cobalt(II) bromide. An idealized equation for the synthesis is:^[1]

9 Co₂(CO)₈ + 4 CHBr₃ → 4 HCCo₃(CO)₉ + 36 CO + 6 CoBr₂

Many analogues are known, including the benzylidyne, arsinidyne, and chloromethylidyne derivatives, respectively C₆H₅CH₂CCo₃(CO)₉,^[1]^[2] AsCo₃(CO)₉, and ClCCo₃(CO)₉.^[3] The potential of some analogues as catalysts for hydroformylation – including with acylidyne and arylidyne moieties – has been investigated.^[4]

The structure has been analyzed by X-ray crystallography. The Co-Co distances are near 2.48 Å in length. The compound is structurally related to tetracobalt dodecacarbonyl.^[5]

References

^ ^a ^b Nestle, Mara O.; Hallgren, John E.; Seyferth, Dietmar; Dawson, Peter; Robinson, Brian H. (1980). "μ₃-Methylidyne and μ₃-Benzylidyne-Tris(Tricarbonylcobalt)". Inorg. Synth. 20: 226–229. doi:10.1002/9780470132517.ch53.
^ Johns, Denise M.; McAuliffe, Charles A. (2007). "Cobalt – Carbonyls". In Johnson, Brian F. G. (ed.). Inorganic Chemistry of the Transition Elements. Vol. 5. Royal Society of Chemistry. pp. 211–213. ISBN 9781847556462.
^ Brown, Alisdair James (1995). Functionalised Transition Metal Clusters of Cobalt and Osmium (PhD thesis). The University of Edinburgh.
^ Seyferth, Dietmar; Withers, Howard P. (1983). "Alkylidynetricobalt nonacarbonyl complexes as hydroformylation catalysts". Inorg. Chem. 22 (20): 2931–2936. doi:10.1021/ic00162a033.
^ Leung, P.; Coppens, P.; McMullan, R. K.; Koetzle, T. F. (1981). "The Structure of Nonacarbonyl-μ₃-methylidyne-triangulo-tricobalt. X-ray and Neutron Diffraction Studies". Acta Crystallogr. B. 37 (7): 1347–1352. doi:10.1107/S0567740881005906.

[InorgSynth-1] Nestle, Mara O.; Hallgren, John E.; Seyferth, Dietmar; Dawson, Peter; Robinson, Brian H. (1980). "μ₃-Methylidyne and μ₃-Benzylidyne-Tris(Tricarbonylcobalt)". Inorg. Synth. 20: 226–229. doi:10.1002/9780470132517.ch53.

[2] Johns, Denise M.; McAuliffe, Charles A. (2007). "Cobalt – Carbonyls". In Johnson, Brian F. G. (ed.). Inorganic Chemistry of the Transition Elements. Vol. 5. Royal Society of Chemistry. pp. 211–213. ISBN 9781847556462.

[3] Brown, Alisdair James (1995). Functionalised Transition Metal Clusters of Cobalt and Osmium (PhD thesis). The University of Edinburgh.

[4] Seyferth, Dietmar; Withers, Howard P. (1983). "Alkylidynetricobalt nonacarbonyl complexes as hydroformylation catalysts". Inorg. Chem. 22 (20): 2931–2936. doi:10.1021/ic00162a033.

[5] Leung, P.; Coppens, P.; McMullan, R. K.; Koetzle, T. F. (1981). "The Structure of Nonacarbonyl-μ₃-methylidyne-triangulo-tricobalt. X-ray and Neutron Diffraction Studies". Acta Crystallogr. B. 37 (7): 1347–1352. doi:10.1107/S0567740881005906.

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