Names | |
---|---|
IUPAC name
Hexadecacarbonylhexarhodium
| |
Other names
Hexarhodium hexadecacarbonyl
| |
Identifiers | |
3D model (JSmol)
|
|
ChemSpider | |
ECHA InfoCard | 100.044.539 |
EC Number |
|
PubChem CID
|
|
CompTox Dashboard (EPA)
|
|
| |
| |
Properties | |
C16O16Rh6 | |
Molar mass | 1065.62 g/mol |
Appearance | purple-brown solid |
Melting point | 235 °C (455 °F; 508 K) |
Hazards | |
GHS labelling: | |
Warning | |
H302, H312, H332 | |
P261, P264, P270, P271, P280, P301+P312, P302+P352, P304+P312, P304+P340, P312, P322, P330, P363, P501 | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|
Hexadecacarbonylhexarhodium is a metal carbonyl cluster with the formula Rh6(CO)16. It exists as purple-brown crystals that are slightly soluble in dichloromethane and chloroform.[1] It is the principal binary carbonyl of rhodium.
Rh6(CO)16 was first prepared by Hieber in 1943 by carbonylation of RhCl3·3H2O at 80–230 °C and 200 atm carbon monoxide with silver or copper as a halide acceptor. Hieber correctly formulated the compound as a binary carbonyl, but suggested the formula Rh4(CO)11, i.e., CO/Rh ratio of 2.75.[2] The correct formula and structure was subsequently established by Dahl et al. using X-ray crystallography. The correct CO/Rh ratio is 2.66.[3]
Relative to the original preparation, the carbonylation of a mixture of anhydrous rhodium trichloride and iron pentacarbonyl was shown to give good yields of Rh6(CO)16.[4] Other compounds of rhodium are also effective precursors such as [(CO)2Rh(μ-Cl)]2 and rhodium(II) acetate:[1]
It also arises quantitatively by thermal decomposition of tetrarhodium dodecacarbonyl in boiling hexane:[5]
At least some of the CO ligands can be displaced by donor ligands.[5]
Rh6(CO)16 catalyzes a number of organic reactions including hydrogenation and hydroformylation.[4]