Title: Aluminum Hydroxydiacetate
CAS Registry Number: 142-03-0
CAS Name: Bis(aceto-k
O)hydroxyaluminum
Synonyms: hydroxybis(acetato)aluminum; basic aluminum acetate; aluminum diacetate; aluminum subacetate; aluminum hydroxyacetate
Trademarks: Lenicet
Molecular Formula: C4H7AlO5
Molecular Weight: 162.08
Percent Composition: C 29.64%, H 4.35%, Al 16.65%, O 49.36%
Line Formula: Al(OH)(CH3CO2)2
Literature References: Prepd from aluminum hydroxide and acetic acid or from sodium acetate and aluminum chloride hexahydrate: Hood, Ihde,
J. Am. Chem. Soc. 72, 2094 (1950). Other methods of prepn:
Gmelins, Aluminum (8th ed.)
35B, p 296 (1934). Also prepd in aq solution,
see Aluminum Subacetate Solution.
Properties: White curdy precipitate or white amorphous powder. Material that has been oven-dried at 110° is practically insoluble in water. Freshly prepared material forms numerous hydrates and is quite sol in water. Greatest soly is obtained by formation in solution. The pharmacist's stock soln (
see Aluminum Subacetate Solution) contains about 8% Al(OH)(CH3CO2)2, while commercial solns used for waterproofing, contain 22 to 25% Al(OH)(CH3CO2)2. When heated, the salt loses acetic acid, and aluminum to oxygen bonding occurs, resulting in a very insol compd of disputed nature,
see Gmelin's, loc. cit. and Thomas,
Pap. Trade J. 100, 36 (1935). Aq solns are generally acid to litmus; gradually become turbid and gelatinous. Sometimes a more basic salt precipitates out and settles to the bottom of the container. Increasing the pH to a marked degree will clear up an old soln due to formation of sodium acetate and sodium aluminate. Urea and thiourea have been suggested as stabilizers for aq solns.
Use: Manuf color lakes; mordant in dyeing; in waterproofing and fireproofing fabrics (solns for these purposes are known as
red liquor or
mordant rouge because they were originally used for preparing red color lakes); in antiperspirant formulations; as disinfectant by embalmers. Dusting powder.
