Rhodium(II) acetate

Rhodium(II) acetate

Names
IUPAC name Rhodium(II) acetate
Other names Dirhodium tetraacetate, Tetrakis(acetato)dirhodium(II), Rhodium diacetate dimer, Tetrakis(μ-acetato)dirhodium
Identifiers
CAS Number	15956-28-2 Y
ChemSpider	20370 Y
ECHA InfoCard	100.036.425
EC Number	240-084-8
PubChem	152122
RTECS number	VI9361000
InChI InChI=1S/2C2H4O2.Rh/c2*1-2(3)4;/h2*1H3,(H,3,4);/q;;+2/p-2 Y Key: ITDJKCJYYAQMRO-UHFFFAOYSA-L Y InChI=1S/4C2H4O2.2Rh/c4*1-2(3)4;;/h4*1H3,(H,3,4);;/q;;;;2*+2/p-4 Key: : SYBXSZMNKDOUCA-UHFFFAOYSA-J
Properties
Chemical formula	C8H12O8Rh2
Molar mass	441.99 g/mol
Appearance	Emerald green powder
Density	1.126 g/cm3
Melting point	>100 °C
Boiling point	decomposes
Solubility in water	soluble
Solubility in other solvents	polar organic solvents
Structure
Crystal structure	monoclinic
Coordination geometry	octahedral
Dipole moment	0 D
Hazards
Safety data sheet	Coleparmer MSDS
R-phrases	36/38
S-phrases	15, 26, 28A, 37/39
NFPA 704	0 3 0
Flash point	low flammability
Related compounds
Related compounds	Copper(II) acetate Chromium(II) acetate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

Rhodium(II) acetate is the chemical compound with the formula Rh₂(AcO)₄, where AcO⁻ is the acetate ion (CH
3CO−
2). This dark green powder is slightly soluble in polar solvents, including water. It is used as a catalyst for cyclopropanation of alkenes.

Rhodium(II) acetate is usually prepared by the heating of hydrated rhodium(III) chloride in acetic acid (CH₃COOH): Rhodium(II) acetate dimer undergoes ligand exchange, the replacement of the acetate group by other carboxylates and related groups.

The structure of rhodium(II) acetate features a pair of rhodium atoms, each with octahedral molecular geometry, defined by four acetate oxygen atoms, water, and a Rh–Rh bond of length 2.39 Å. The water adduct is exchangeable, and a variety of other Lewis bases bind to the axial positions.Copper(II) acetate and chromium(II) acetate adopt similar structures.

The application of dirhodium tetraacetate to organic synthesis was pioneered by Teyssie and co-workers. An extensive range of reactions including insertion into O–H and N–H bonds and the cyclopropanation of olefins. and aromatic systems. It selectively binds ribonucleosides (vs. deoxynucleosides) by binding selectively to ribonucleosides at their 2′ and 3′ –OH groups. Rhodium(II) acetate dimer, compared to copper(II) acetate, is more reactive and useful in differentiating ribonucleosides and deoxynucleosides because it is soluble in aqueous solution like water whereas copper(II) acetate only dissolves in non-aqueous solution.