Nucleophilic Activation of Sulfur Hexafluoride: Metal-Free, Selective Degradation by Phosphines.

The development of new methods for the chemical activation of the extremely inert greenhouse gas sulfur hexafluoride (SF ) not only is of current environmental interest, but also offers new opportunities for applications of SF as a reagent in organic synthesis. We herein report the first nucleophilic activation of SF by Lewis bases, namely by phosphines, which results either in its complete degradation to phosphine sulfides and difluorophosphoranes or in the selective conversion of SF into a bench-stable, crystalline salt containing the SF anion. Quantum chemical calculations reveal a nucleophilic substitution mechanism (S 2) for the initial fluorine abstraction from SF by the phosphine. Furthermore, a scalable one-pot procedure for the complete decomposition of SF into solid, nonvolatile products is presented based on cheap and commercially available starting materials.