Nucleophilic Activation of Sulfur Hexafluoride: Metal‐Free, Selective Degradation by Phosphines. Issue 18 (22nd March 2018)

• Record Type: Journal Article
• Authors: Buß, Florenz; Mück‐Lichtenfeld, Christian; Mehlmann, Paul; Dielmann, Fabian
• Is Part Of: Angewandte Chemie international edition. Volume 57:Issue 18(2018)
• Page Start: 4951
• Page End: 4955
• Publication Date: 2018-03-22
• Subjects: difluorophosphoranes -- greenhouse gases -- nucleophilic addition -- phosphines -- sulfur hexafluoride; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201713206
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: The development of new methods for the chemical activation of the extremely inert greenhouse gas sulfur hexafluoride (SF6 ) not only is of current environmental interest, but also offers new opportunities for applications of SF6 as a reagent in organic synthesis. We herein report the first nucleophilic activation of SF6 by Lewis bases, namely by phosphines, which results either in its complete degradation to phosphine sulfides and difluorophosphoranes or in the selective conversion of SF6 into a bench‐stable, crystalline salt containing the SF5 − anion. Quantum chemical calculations reveal a nucleophilic substitution mechanism (SN 2) for the initial fluorine abstraction from SF6 by the phosphine. Furthermore, a scalable one‐pot procedure for the complete decomposition of SF6 into solid, nonvolatile products is presented based on cheap and commercially available starting materials. Abstract : Yes "P" can ! The nucleophilic attack of a superbasic phosphine on a fluorine atom of SF6 enables its selective degradation. Depending on the phosphine's basicity, either a mixture of difluorophosphoranes and phosphine sulfides is formed, or the SF6 molecule is converted into a salt containing the SF5 − anion. In addition, a scalable one‐pot procedure for the depletion of this greenhouse gas has been developed.