Harnessing the (CH3)2ZnCl- Anion for Dimethylzinc Stabilization as a Pathway to Stable Dimethylzinc Salts and Dimethylzinc Recovery.

Abstract

The possibility of stabilizing reactive dimethylzinc through salt formation has been investigated using advanced ab initio electronic structure methods and flexible basis sets. It was found that the attachment of a Cl^- ion to dimethylzinc is thermodynamically favorable (with a Gibbs free reaction energy of -22.88 kcal/mol at room temperature), occurring without a kinetic barrier. The resulting anion is strongly electronically bound, with an excess electron binding energy of 4.306 eV. The subsequent attachment of Li⁺ or Na⁺ ions to this anion leads to the formation of ionic salts (CH₃)₂ZnClLi or (CH₃)₂ZnClNa. These salts, formed through this two-step process, are thermodynamically stable and represent stabilized forms of dimethylzinc, from which the pure dimethylzinc compound can be regenerated via the procedures suggested in this work. In addition to the structural characterization of these systems and a detailed analysis of the electronic structure of the (CH₃)₂ZnCl^- anion, which plays a key role in the described process, experimental approaches for realizing each transformation are also proposed.