Tetrairidium dodecacarbonyl

Tetrairidium dodecacarbonyl
Names
	IUPAC names dodecacarbonyl-1κ3C,2κ3C,3κ3C,4κ3C-[Td-(13)-Δ4-closo]-tetrairidium(6 Ir—Ir); tetrahedro-tetrakis(tricarbonyliridium)(6 Ir—Ir)
	Other names iridium(0) carbonyl; iridium carbonyl; iridium dodecacarbonyl
Identifiers
CAS Number	18827-81-1 ;
3D model (JSmol)	Interactive image;
ChemSpider	21171017;
ECHA InfoCard	100.038.718
EC Number	242-607-5;
PubChem CID	16211901;
CompTox Dashboard (EPA)	DTXSID80474907 ;
	InChI InChI=1S/12CO.4Ir/c12*1-2;;;; Key: XWDKRVSSHIJNJP-UHFFFAOYSA-N;
	SMILES [O+]#C[Ir-3]12(C#[O+])(C#[O+])[Ir-3]3(C#[O+])(C#[O+])(C#[O+])[Ir-3]1(C#[O+])(C#[O+])(C#[O+])[Ir-3]23(C#[O+])(C#[O+])C#[O+];
Properties
Chemical formula	Ir4(CO)12
Molar mass	1104.92 g/mol
Appearance	Canary-yellow crystals
Melting point	195 °C (383 °F; 468 K)
Solubility	Chlorocarbons, toluene, tetrahydrofuran
Related compounds
Related compounds	Tetrarhodium dodecacarbonyl
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Tetrairidium dodecacarbonyl is the chemical compound with the formula Ir₄(CO)₁₂. This tetrahedral cluster is the most common and most stable "binary" carbonyl of iridium. This air-stable species is only poorly soluble in organic solvents.^[1]^[2]^[3] It has been used to prepare bimetallic clusters and catalysts, e.g. for the water gas shift reaction, and reforming, but these studies are of purely academic interest.

Structure[edit]

Each Ir center is octahedral, being bonded to 3 other iridium atoms and three terminal CO ligands. Ir₄(CO)₁₂ has T_d symmetry with an average Ir-Ir distances of 2.693 Å.^[4] The related clusters Rh₄(CO)₁₂ and Co₄(CO)₁₂ have C_3v symmetry because of the presence of three bridging CO ligands in each.

Preparation[edit]

It is prepared in two steps by reductive carbonylation of hydrated iridium trichloride. The first step gives [Ir(CO)₂Cl₂]⁻.^[5]

IrCl₃ + 3 CO + H₂O → [Ir(CO)₂Cl₂]⁻ + CO₂ + 2 H⁺ + Cl⁻

4 [Ir(CO)₂Cl₂]⁻ + 6 CO + 2 H₂O → Ir₄(CO)₁₂ + 2 CO₂ + 4 H⁺ + 8 Cl⁻

References[edit]

^ "Tetrairidium dodecacarbonyl". WebElements. Retrieved 16 July 2021.
^ Uzun, Alper; Dixon, David A.; Gates, Bruce C. (10 January 2011). "Prototype Supported Metal Cluster Catalysts: Ir4 and Ir6". ChemCatChem. 3 (1): 95–107. doi:10.1002/cctc.201000271. S2CID 96876029. Retrieved 16 July 2021.
^ Muetterties, E L; Burch, R R; Stolzenberg, A M (October 1982). "Molecular Features of Metal Cluster Reactions". Annual Review of Physical Chemistry. 33 (1): 89–118. Bibcode:1982ARPC...33...89M. doi:10.1146/annurev.pc.33.100182.000513. Retrieved 16 July 2021.
^ Churchill, Melvyn Rowen; Hutchinson, John P. (1978). "Crystal Structure of tetrairidium dodecacarbonyl, Ir₄(CO)₁₂. An Unpleasant Case of Disorder". Inorganic Chemistry. 17 (12): 3528–35. doi:10.1021/ic50190a040.
^ Pergola, R. D.; Garlaschelli, L.; Matinengo, S. (1990). Dodecacarbonyltetrairidium: Ir₄(CO)₁₂. Inorganic Syntheses. Vol. 28. pp. 245–247. doi:10.1002/9780470132593.ch63. ISBN 9780470132593.

[WebElements-1] "Tetrairidium dodecacarbonyl". WebElements. Retrieved 16 July 2021.

[Uzun-2] Uzun, Alper; Dixon, David A.; Gates, Bruce C. (10 January 2011). "Prototype Supported Metal Cluster Catalysts: Ir4 and Ir6". ChemCatChem. 3 (1): 95–107. doi:10.1002/cctc.201000271. S2CID 96876029. Retrieved 16 July 2021.

[Muetterties-3] Muetterties, E L; Burch, R R; Stolzenberg, A M (October 1982). "Molecular Features of Metal Cluster Reactions". Annual Review of Physical Chemistry. 33 (1): 89–118. Bibcode:1982ARPC...33...89M. doi:10.1146/annurev.pc.33.100182.000513. Retrieved 16 July 2021.

[4] Churchill, Melvyn Rowen; Hutchinson, John P. (1978). "Crystal Structure of tetrairidium dodecacarbonyl, Ir₄(CO)₁₂. An Unpleasant Case of Disorder". Inorganic Chemistry. 17 (12): 3528–35. doi:10.1021/ic50190a040.

[5] Pergola, R. D.; Garlaschelli, L.; Matinengo, S. (1990). Dodecacarbonyltetrairidium: Ir₄(CO)₁₂. Inorganic Syntheses. Vol. 28. pp. 245–247. doi:10.1002/9780470132593.ch63. ISBN 9780470132593.

[1]

[2]

[3]

[4]

[5]