• Source: Rhodium(II) trifluoroacetate

Rhodium trifluoroacetate is the chemical compound with the formula Rh2(O2CCF3)4. It is used as a catalyst in the synthesis of some organic compounds. The compound and its derivatives have been extensively characterized by X-ray crystallography. It adopts the Chinese lantern structure seen for many dimetal carboxylate complexes. This structure accommodates a Rh-Rh bond, the existence of which explains the diamagnetism of this Rh(II) species. The Rh-Rh distance is 238 pm.
The anhydrous complex is a green volatile solid. It is prepared by dissolving rhodium(II) acetate in hot trifluoroacetic acid:

Rh2(O2CCH3)4 + 4 HO2CCF3 → Rh2(O2CCF3)4 + 4 HO2CCH3
This reaction expels acetic acid. The Rh-Rh bond is retained.




Reactions


Rhodium(II) trifluoroacetate forms adducts with a variety of Lewis bases. The structures typically have a 2:1 stoichiometry, with one base binding at the "axial" position on each of the two Rh(II) centers:

Rh2(O2CCF3)4 + 2 L → Rh2(O2CCF3)4L2 (L = CO, RCN, R2SO, R3P, ...)
Rhodium(II) trifluoroacetate binds even very weak bases, moreso than does rhodium(II) acetate. It even forms adducts with hexamethylbenzene and with S8.
Rhodium(II) trifluoroacetate catalyzes cyclopropanation of alkenes by diazo compounds:
RCH=CR'H + CH3CH2O2CCH(N2) → cyclo−(RCH)(R'CH)(CH3CH2O2CCH) + N2




References

Kata Kunci Pencarian:

• Rhodium(II) trifluoroacetate
• Rhodium(II) acetate
• Rhodium
• Cyclopropanation
• Transition metal carboxylate complex
• Roy A. Periana
• List of CAS numbers by chemical compound
• Caesium
• Insertion reaction