Harman Patil (Editor)

Lead(IV) acetate

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Formula
  
Pb(C2H3O2)4

Density
  
2.23 g/cm³

Molar mass
  
443.38 g/mol

Melting point
  
175 °C

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Appearance
  
colorless or pink crystals

Lead(IV) acetate or lead tetraacetate is a chemical compound with chemical formula Pb(C2H3O2)4 and is a lead salt of acetic acid. It is commercially available often stabilized with acetic acid.

Contents

Structure

In the solid state the lead atoms are surrounded by four acetate ions which are bidentate, each coordinating via two oxygen atoms. The lead atom is 8 coordinate and the O atoms form a flattened trigonal dodecahedron.

Preparation

It can be prepared by reaction of red lead with acetic acid. The other main lead acetate is lead(II) acetate.

Reagent in organic chemistry

Lead tetraacetate is a strong oxidizing agent, a source of acetyloxy groups and a general reagent for the introduction of lead into organolead compounds. Some of its many uses in organic chemistry:

  • acetoxylation of benzylic, allylic and α-oxygen ether C-H bonds, for example the photochemical conversion of dioxane to 1,4-dioxene through the 2-acetoxy-1,4-dioxane intermediate and the conversion of α-pinene to verbenone
  • an alternative reagent to bromine in Hofmann rearrangement
  • oxidation of hydrazones to diazo compounds for example that of hexafluoroacetone hydrazone to bis(trifluoromethyl)diazomethane
  • aziridine formation, for example the reaction of N-aminophthalimide and stilbene
  • cleavage of α-hydroxy acids or 1,2-diols to their corresponding aldehydes or ketones, often replacing ozonolysis; for instance, the oxidation of di-n-butyl d-tartrate to n-butyl glyoxylate.
  • reaction with alkenes to form γ-lactones
  • oxidation of alcohols carrying a δ-proton to cyclic ethers.
  • Oxidative cleavage of certain allyl alcohols in conjunction with ozone:
  • conversion of acetophenones to phenyl acetic acids
  • Decarboxylation of carboxylic acids to alkyl halides in the Kochi reaction

    • Safety

    Lead(IV) acetate may be fatal if ingested, inhaled, or absorbed through skin. It causes irritation to skin, eyes, and respiratory tract. It is a neurotoxin. It affects the gum tissue, central nervous system, kidneys, blood, and reproductive system. Its oxidising nature can indirectly lead to many diseases, even cancer, by free radical mechanism.

    References

    Lead(IV) acetate Wikipedia
    (Text) CC BY-SA