Palladium(II) acetate

Palladium(II) acetate

Names
IUPAC name Palladium(II) acetate
Other names Palladium diacetate hexakis(acetato)tripalladium bis(acetato)palladium
Identifiers
CAS Number	3375-31-3 Y
3D model (Jmol)	Interactive image
ChemSpider	146827 Y
ECHA InfoCard	100.020.151
PubChem	167845
RTECS number	AJ1900000
InChI InChI=1S/2C2H4O2.Pd/c2*1-2(3)4;/h2*1H3,(H,3,4);/q;;+2/p-2 Y Key: YJVFFLUZDVXJQI-UHFFFAOYSA-L Y InChI=1/2C2H4O2.Pd/c2*1-2(3)4;/h2*1H3,(H,3,4);/q;;+2/p-2 Key: YJVFFLUZDVXJQI-NUQVWONBAH
SMILES [Pd+2].[O-]C(=O)C.[O-]C(=O)C
Properties
Chemical formula	Pd(CH3COO)2
Molar mass	224.50 g/mol
Appearance	Brown yellow solid
Density	2.19 g/cm3
Melting point	205 °C (401 °F; 478 K) decomposes
Boiling point	decomposes
Solubility in water	low
Structure
Crystal structure	monoclinic
Coordination geometry	Square Planar
Dipole moment	0 D
Hazards
Main hazards	considered nonhazardous
Safety data sheet	[1]
R-phrases	41
S-phrases	24/25
Related compounds
Other anions	Palladium(II) chloride
Other cations	Platinum(II) acetate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y  (what is YN ?)
Infobox references

Palladium(II) acetate is a chemical compound of palladium described by the formula Pd(O₂CCH₃)₂ or Pd(OAc)₂. It is considered more reactive than the analogous platinum compound. It is soluble in many organic solvents, and commonly used as a catalyst for organic reactions and as a precursor for the synthesis of other palladium catalysts.

Although the compound is a 1:2 stoichiometric ratio of palladium atoms and acetate ligands as their oxidation states suggest, the actual molecular nature of the chemical depends on how it is prepared.

As prepared by Wilkinson and coworkers in 1965, and later studied by Skapski and Smart in 1970 by single crystal X-ray diffraction, palladium(II) acetate is a red-brown solid that crystallizes as monoclinic plates. Its structure was determined to be trimeric, consisting of an equilateral triangle of Pd atoms each pair of which is bridged with two acetate groups in a butterfly conformation. Each metal atom achieves approximate square planar co-ordination.

On the other hand, palladium(II) acetate prepared in a slightly different way was isolated as a pale pink powder, whose structure was determined by X-ray powder diffraction to consist of infinite chains of palladium atoms, each linked by an adjacent pair of acetate bridges to the next, in which the coordination geometry around each Pd is true square planar.

Palladium acetate, in trimeric form, can be prepared by refluxing palladium sponge with hot glacial acetic acid and nitric acid. An excess of palladium sponge metal or nitrogen gas flow is used to prevent contamination by a material that contains a nitrite ligand in place of one of the acetates (Pd₃(OAc)₅NO₂).

The nitro variant has different solubility and catalytic activity in some reactions. Preventing, or controlling for the amount of, this impurity can be an important aspect for reliable use of palladium(II) acetate.

Palladium(II) propionate is prepared analogously; other carboxylates are prepared by reacting palladium(II) acetate with the appropriate carboxylic acid. Likewise, palladium(II) acetate can be prepared by reacting other palladium(II) carboxylates with acetic acid. This ligand exchange starting with a purified other carboxylate is an alternative way to synthesize palladium(II) acetate free from the nitro contaminant.