Basic beryllium acetate is the best known of the beryllium salts of organic acids which can be divided into normal beryllium carboxylates, Be(RCOO)2, and beryllium oxide carboxylates, Be4O(RCOO)6. The basic acetate is soluble in glacial acetic acid and can readily be crystallized therefrom in very pure form. It is also soluble in chloroform and other organic solvents. It has been used as a source of pure beryllium salts.
Method I: Basic beryllium carbonate (40 g) is mixed with 80 ml of glacial acetic acid and stirred, with heating, until CO2 evolution ceases. The end of the reaction is also recognized by the start of precipitation of white, semi-translucent crystals; otherwise, there is an amorphous white residue. The solution is cooled to room temperature, and the crystallized basic acetate is filtered off and dried in air. The crude product is treated with 60-80 ml of chloroform, and any insoluble residue is removed by filtration. The basic salt, which crystallizes in colourless octahedra, is filtered off and freed of residual chloroform in a vacuum desiccator. Beryllium oxyacetate melts at 284°C and sublimes without a residue at reduced pressure. The yield is 28 g.
Method II: A method described by Hardt avoids contamination of the product by ammonium salts and solvent occlusions and makes purification by sublimation unnecessary. Beryllium hydroxide or basic beryllium carbonate is stirred with glacial acetic acid to a paste and evaporated to dryness in a laboratory oven at 120 to 130°C. The crude product thus formed is extracted with glacial acetic acid in a Soxhlet apparatus (using a glass wool filter); after cooling, it crystallizes from the extract in well-formed octahedra, filtered off and dried at 130°C. This is followed by a second Soxhlet extraction with CCl4 since the ammonium salts from the starting material remain undissolved. The product is analytically pure after drying at 100°C.
Confirmed carcinogen. SeeBERYLLIUM COMPOUNDS. When heated todecomposition it emits toxic fumes of BeO.
Very soluble in chloroform; readily soluble in boiling benzene, toluene, xylene, Tetralin and glacial acetic acid; less soluble in CCl4, acetic anhydride and acetyl chloride; sparingly soluble (0.3%) in diethyl ether. In anhydrous boiling methanol, following initial dissolution, splits off acetic anhydride with the formation of highly aggregated basic acetates. It is quite stable in cold water but is rapidly hydrolyzed in hot water.
