Premium
An Acyclic Arsenium Cation Stabilised by a Single P–As π‐Interaction and a Cyclic Diphosphinophosphonium Salt
Author(s) -
Izod Keith,
Evans Peter,
Waddell Paul G.
Publication year - 2019
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201905922
Subject(s) - chemistry , salt (chemistry) , phosphonium , phosphine , lone pair , phosphonium salt , crystallography , stereochemistry , medicinal chemistry , polymer chemistry , organic chemistry , molecule , catalysis
Stable acyclic arsenium cations R 2 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(CF 3 ) 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.