Synthesis of alumoxanes by reactions of organoaluminum compounds with copper sulfate crystallohydrate

Abstract

1. The reaction of aluminum trialkyls and dialkylaluminum chlorides with the water of CuSO4·5H2O in an aromatic hydrocarbon proceeds via the hydrolysis of one of the Al-C bonds and makes it possible to obtain the pure alkyl- and alkylchloroalumoxanes in high yields. 2. In the ability of the Al-C bond to undergo hydrolysis, the organoaluminum compounds can be arranged in the following order: C2H5AlCl2>(C2H5)2AlCl >(C2H5)3Al, which coincides with the order of the Lewis acid properties of aluminum compounds, and is the opposite of the order of their ability to be reduced. 3. The formation rate of the alumoxanes decreases when benzene is replaced by its alkyl derivatives. 4. The reaction of the water of CuSO4·5H2O with organoaluminum compounds begins with dehydration of the salt, which represents a topochemical reaction that is described by the Erofeev-Kolmogorov equation.