An Acyclic Arsenium Cation Stabilised by a Single P–As π‐Interaction and a Cyclic Diphosphinophosphonium Salt. Issue 32 (3rd July 2019)

• Record Type: Journal Article
• Authors: Izod, Keith; Evans, Peter; Waddell, Paul G.
• Is Part Of: Angewandte Chemie international edition. Volume 58:Issue 32(2019)
• Page Start: 11007
• Page End: 11012
• Publication Date: 2019-07-03
• Subjects: arsenic -- main group chemistry -- π-interactions -- P-ligands -- solid-state structures; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201905922
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Stable acyclic arsenium cations R2 As +, isoelectronic analogues of germylenes, are rare in comparison to the corresponding phosphenium cations. The first example of a diphosphaarsenium salt, [{(Dipp)2 P}2 As][Al{OC(CF3 )3 }4 ]⋅1 1 / 2 PhMe, is described. This salt exhibits remarkable stability due to the delocalisation of a lone pair from a planar phosphorus centre into the vacant p‐orbital at arsenic; the bonding in 2 has been probed by DFT calculations. An attempt to synthesise an analogous diphosphaphosphenium salt unexpectedly generated the cyclic phosphonium salt [ cyclo ‐{(Mes)P}2 P(Mes)2 ][BAr F 4 ]⋅CyMe through the cyclisation of a putative phosphine‐substituted diphosphene cation intermediate. Abstract : The first diphosphaarsenium cation has been synthesised. This cation exhibits remarkable stability because of the delocalisation of a lone pair from a planar phosphorus centre into the vacant arsenic p‐orbital.