Ammonia → Cobalt(3+) acetylacetonate

Participants

Reaction Conditions

Reaction Steps

582.5 grams cobalt(II)acetylacetonate, made from cobalt dichloride and acetylacetone by reaction with ammonia, having a water content of 11.7% by weight, corresponding to 509.6 grams of the anhydrous compound, were dissolved in 2 liters of methanol at room temperature and thereto 210 grams of acetylacetone were added at 35° C, while stirring. Subsequently, to the clear solution 150 grams hydrogen peroxide of about 30% were added within 8 minutes, which led to an increase in temperature of the solution to 65° C. The solution was then stirred at 65° C for about 30 minutes, and another 80 grams of about 30% hydrogen peroxide were added until the solution had turned to a clear green color. Thereafter, the reaction mixture was heated to reflux for one hour, cooled to 3° C, and the precipitated cobalt(III)acetylacetonate filtered and washed with 100 ml of cold methanol. After drying at 5 torr/80° C for 5 hours, 539 grams cobalt(III)acetylacetonate were obtained (corresponding to 75.7% of the theoretical). The product was black and shining, and of finely-crystalline structure, and having a water content of less than 0.05% by weight.

Provenance & Evidence