Mercury(II) acetate

Mercury(II) acetate, also known as mercuric acetate is a chemical compound, the mercury(II) salt of acetic acid, with the formula Hg(O₂CCH₃)₂. Commonly abbreviated Hg(OAc)₂, this compound is employed as a reagent to generate organomercury compounds from unsaturated organic precursors. It is a white, water-soluble solid, but some samples can appear yellowish with time owing to decomposition.

Mercury(II) acetate

Names
Other names mercuric acetate mercuriacetate mercury diacetate
Identifiers
CAS Number	1600-27-7 Y
3D model (JSmol)	ionic form: Interactive image coordination form: Interactive image
ChEBI	CHEBI:33211 Y
ChemSpider	14599 Y
ECHA InfoCard	100.014.993
EC Number	209-766-2
PubChem CID	15337
RTECS number	AI8575000
UNII	R0G1MCT8Y5 Y
UN number	1629
CompTox Dashboard (EPA)	DTXSID4042123
InChI InChI=1S/2C2H4O2.Hg/c2*1-2(3)4;/h2*1H3,(H,3,4);/q;;+2/p-2 Y Key: BRMYZIKAHFEUFJ-UHFFFAOYSA-L Y InChI=1/2C2H4O2.Hg/c2*1-2(3)4;/h2*1H3,(H,3,4);/q;;+2/p-2 Key: BRMYZIKAHFEUFJ-NUQVWONBAS
SMILES ionic form: [Hg+2].[O-]C(=O)C.[O-]C(=O)C coordination form: O=C(C)O[Hg]OC(C)=O
Properties
Chemical formula	C4H6O4Hg
Molar mass	318.678 g/mol
Appearance	white solid
Odor	mild vinegar odor
Density	3.28 g/cm3, solid
Melting point	179 °C (354 °F; 452 K) (decomposes)
Solubility in water	25 g/100 mL (10 °C) 100 g/100 mL (100 °C)
Solubility	soluble in alcohol, diethyl ether
Magnetic susceptibility (χ)	−100·10−6 cm3/mol
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H300, H310, H330, H373, H410
Precautionary statements	P260, P262, P264, P270, P271, P273, P280, P284, P301+P310, P302+P350, P304+P340, P310, P314, P320, P321, P322, P330, P361, P363, P391, P403+P233, P405, P501
NFPA 704 (fire diamond)	4 0 0
Lethal dose or concentration (LD, LC):
LD50 (median dose)	40.9 mg/kg (rat, oral) 23.9 mg/kg (mouse, oral)[1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Structure

Mercury(II) acetate is a crystalline solid consisting of isolated Hg(OAc)₂ molecules with Hg-O distances of 2.07 Å. Three long, weak intermolecular Hg···O bonds of about 2.75 Å are also present, resulting in a slightly distorted square pyramidal coordination geometry at Hg.^[2]

Synthesis and reactions

Mercury(II) acetate can be produced by reaction of mercuric oxide with acetic acid.^[3]

HgO + 2 CH₃COOH → Hg(CH₃COO)₂ + H₂O

Inorganic reactions

Mercury(II) acetate in acetic acid solution reacts with H₂S to rapidly precipitate the black (β) polymorph of HgS. With gentle heating of the slurry, the black solid converts to the red form.^[4] The mineral cinnabar is red HgS. The precipitation of HgS as well as a few other sulfides, using hydrogen sulfide is a step in qualitative inorganic analysis.

Organic chemistry

Electron-rich arenes undergo "mercuration" upon treatment with Hg(OAc)₂. This behavior is illustrated with phenol:

C₆H₅OH + Hg(OAc)₂ → C₆H₄(OH)-2-HgOAc + HOAc

The acetate group (OAc) that remains on mercury can be displaced by chloride:^[5]

C₆H₄(OH)-2-HgOAc + NaCl → C₆H₄(OH)-2-HgCl + NaOAc

The Hg²⁺ center binds to alkenes, inducing the addition of hydroxide and alkoxide. For example, treatment of methyl acrylate with mercuric acetate in methanol gives an α-mercuri ester:^[6]

Hg(OAc)₂ + CH₂=CHCO₂CH₃ + CH₃OH → CH₃OCH₂CH(HgOAc)CO₂CH₃ + HOAc

Exploiting the high affinity of mercury(II) for sulfur ligands, Hg(OAc)₂ can be used as a reagent to deprotect thiol groups in organic synthesis. Similarly Hg(OAc)₂ has been used to convert thiocarbonate esters into dithiocarbonates:

(RS)₂C=S + H₂O + Hg(OAc)₂ → (RS)₂C=O + HgS + 2 HOAc

Mercury(II) acetate is used for oxymercuration reactions.

A famous use of Hg(OAc)₂ was in the synthesis of idoxuridine.

Toxicity

Main article: Mercury poisoning

Mercuric acetate is a highly toxic compound, due to it being water-soluble and having mercury ions. Symptoms of mercury poisoning include peripheral neuropathy, skin discoloration and desquamation (peeling and/or shedding of the skin).^[7] Chronic exposure may cause reduced intelligence and kidney failure.^[8]