Tetrairidium dodecacarbonyl
Names | |
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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 | |
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3D model (JSmol) | |
ChemSpider | |
ECHA InfoCard | 100.038.718 |
EC Number |
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PubChem CID | |
CompTox Dashboard (EPA) | |
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Properties | |
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). |
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 Td symmetry with an average Ir-Ir distances of 2.693 Å.[4] The related clusters Rh4(CO)12 and Co4(CO)12 have C3v 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.