Zinc acetate

Zinc acetate
IUPAC name Zinc acetate
Other names Acetic acid, Zinc salt Acetic acid, Zinc(II) salt Dicarbomethoxyzinc Zinc diacetate
Identifiers
CAS number	557-34-6 Y, 5970-45-6
PubChem	11192
ChemSpider	10719 Y
UNII	H2ZEY72PME Y
ChEMBL	CHEMBL1200928
RTECS number	ZG8750000
Jmol-3D images	Image 1
SMILES [Zn+2].[O-]C(=O)C.[O-]C(=O)C
InChI InChI=1S/2C2H4O2.Zn/c2*1-2(3)4;/h2*1H3,(H,3,4);/q;;+2/p-2 Y Key: DJWUNCQRNNEAKC-UHFFFAOYSA-L Y InChI=1/2C2H4O2.Zn/c2*1-2(3)4;/h2*1H3,(H,3,4);/q;;+2/p-2 Key: DJWUNCQRNNEAKC-NUQVWONBAP
Properties
Molecular formula	C4H10O6Zn (dihydrate)
Molar mass	219.50 g/mol (dihydrate) 183.48 g/mol (anhydrous)
Appearance	White solid (all forms)
Density	1.735 g/cm3 (dihydrate)
Melting point	Decomposes 237 °C (dihydrate loses water at 100 °C)
Boiling point	decomp.
Solubility in water	43 g/100 mL (20 °C, dihydrate)
Solubility	soluble in alcohol
Structure
Coordination geometry	octahedral (dihydrate)
Molecular shape	tetrahedral
Hazards
R-phrases	R22 R36 R50/53
S-phrases	S26 S60 S61
Main hazards	mildly toxic
Related compounds
Other anions	Zinc chloride
Other cations	Copper(II) acetate
Related compounds	Basic beryllium acetate
Y acetate (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Zinc acetate is the chemical compound with the formula Zn(O₂CCH₃)₂, which commonly occurs as a dihydrate Zn(O₂CCH₃)₂(H₂O)₂. Both the hydrate and the anhydrous forms are colorless solids that are commonly used in chemical synthesis and as dietary supplements. Zinc acetates are prepared by the action of acetic acid on zinc carbonate or zinc metal. When used as a food additive, it has the E number E650.

Basic properties and structures

The acetate group is capable of binding to metal ions in a variety of ways through its two oxygen atoms and several connectivities are observed for the various hydrates of zinc acetate. Anhydrous zinc acetate adopts a polymeric structure consisting of zinc coordinated to four oxygen atoms in a tetrahedral environment, each tetrahedron being connected to neighbors by the acetate groups.^[1] The acetate ligands are not bidentate. In contrast, most metal diacetates feature metals in octahedral coordination with bidentate acetate groups. In zinc acetate dihydrate the zinc is octahedral, wherein both acetate groups are bidentate.^[2]

Basic zinc acetate

Heating Zn(CH₃CO₂)₂ in a vacuum results in loss of acetic anhydride, leaving a residue of "basic zinc acetate," with the formula Zn₄O(CH₃CO₂)₆. This cluster compound has the tetrahedral structure shown below. This species closely resembles the corresponding beryllium compound, although it is slightly expanded with Zn-O distances ~1.97 vs ~1.63 Å for Be₄O(OAc)₆.^[3]

Applications

Dietary and medicinal applications

Zinc acetate is used as a dietary supplement and in lozenges used to treat the common cold. Zinc acetate alone is thought to be a more effective treatment than zinc gluconate.^[4]

Zinc acetate can also be used to treat zinc deficiencies. As an oral daily supplement it is used to inhibit the body's absorption of copper as part of the treatment for Wilson's disease. Zinc acetate is also sold as an astringent in the form of an ointment, a topical lotion; or combined with an antibiotic such as erythromycin for the topical treatment of acne. Furthermore Zinc acetate is commonly sold as a topical anti-itch ointment.

In chewing gum, zinc acetate is a breath freshener^[5][6] and plaque inhibitor^[7].

Industrial applications

Industrial applications include wood preserving, manufacturing other zinc salts, polymers, manufacture of ethylene acetate, as a dye mordant, and analytical reagent.

Zinc acetate is a precursor via a sol-gel route to the transparent semiconductor zinc oxide.

References

1. ^ Capilla, A. V.; Aranda, R. A. (1979). "Anhydrous Zinc(II) Acetate (CH₃-COO)₂Zn". Crystal Structure Communications 8: 795–797. 
2. ^ J. N. van Niekerk, F. R. L. Schoening and J. H. Talbot (1953). "The crystal structure of zinc acetate dihydrate, Zn(CH₃COO)₂·2H₂O". Acta Cryst. 6 (8): 720–723. doi:10.1107/S0365110X53002015. 
3. ^ Koyama, H.; Saito, Y. (1954). "The Crystal Structure of Zinc Oxyacetate, Zn₄O(CH₃COO)₆". Bull. Chem. Soc. Japan 27 (2): 112–114. doi:10.1246/bcsj.27.112. 
4. ^ Eby GA (2004). "Zinc lozenges: cold cure or candy? Solution chemistry determinations". Biosci. Rep. 24 (1): 23–39. doi:10.1023/B:BIRE.0000037754.71063.41. PMID 15499830. http://george-eby-research.com/html/common-cold.pdf. 
5. ^ US 7087255 
6. ^ US 6592849 
7. ^ Giertsen E, Svatun B, Saxton A (February 1987). "Plaque inhibition by hexetidine and zinc". Scand J Dent Res 95 (1): 49–54. PMID 3470899.