Ethylzinc hydroxide as an intermediate in the reaction of diethylzinc with water

Abstract The diethylzinc/water ( 1 1 mol) reaction in 1,4-dioxane as solvent has been studied by applying the cryoscopic method for molecular weight determinations to the products formed in the reaction solution. An ethylzinc hydroxide dimer was found to be formed as an intermediate in the reaction system during fast ethane elimination. Monomeric ethylzinc[tri(oxyzinc)] hydroxide was found to be the main product of the subsequent reaction of this intermediate, with further ethane elimination. A mechanism for the latter reaction, involving the formation of a transient ethylzinc hydroxide tetrameric species, is proposed. The reaction pathway in the diethylzinc/water ( 2 1 mol) system is also discussed. The formation of ethylzinc[tri(oxyzinc)] hydroxide, as in the 1 1 system, followed by the subsequent reaction of this compound with diethylzinc gave further ethane elimination and lead to ethylzinc[tri(oxyzinc)] ethylzinc oxide as the main product, is the proposed route in this case. In contrast to diethylzinc, which is too weak a Lewis acid to react with the ethylzinc hydroxide dimer, trimethylaluminium was found to undergo reaction with it in 1,4-dioxane solution, with fast methane and ethane elimination.