Strong P=P π Bonds: The First Synthesis of a Stable Phosphanyl Phosphenium Ion

Abstract

A 35-fold excess of methyl triflate (2) is required to quantitively prepare 3, the first phosphanyl phosphenium ion, from diphosphene 1. Experimental data and calculations indicate that the P=P bond becomes stronger upon alkylation.

Synthesis, Structures, and Reactivity of Kinetically Stabilized Anthryldiphosphene Derivatives

“…55 The phosphorus atom of 1b bearing the anthryl group may attack the C=C bond of 30c due to steric reasons to give 32, which may retain its P=P double-bond analogously to a previous report of an isolated phosphanyl phosphenium ion, [Mes*P=P(Me)Mes*] + bearing significant P=P double-bond character. 56 Taking into consideration the zwitterionic species 32, the ³-bond of the (NC)C=C(CN) moiety of 32 should be weakened enough to be rotated along with the CC axis to give 32¤. Then, the cleavage of the PC bond of 32¤ should occur to afford 1b and maleonitrile.…”

Reactivity of Diimido Complexes of Moybdenum and Tungsten towards Lithium Derivatives of Diphosphanes and Triphosphanes

“…The most striking feature of both structures is the sideon bonding mode of the R 2 P2=P1 fragment belonging to the ligand R 2 P=P-PR 2 , which was first observed for [(1,2η 2 -R 2 P=P-PR 2 )M(Cl)L] (L = tertiary phosphine; M = Ni, Pd, Pt). [33,34] The bonding situation of these dihapto ligands is such that the cation can be described as a diphosphenium cation [35] (Scheme 5, structure A) with a significant contribution from the second canonical structure B representing the non-classical phosphido ligand. Similar structures are known for complexes of Ni group metals with the η 2 -bonded tBu 2 -P-PtBu 2 ligand.…”

A Crystalline Phosphenium Salt Featuring the Electron-Withdrawing 2,6-Bis(trifluoromethyl)phenyl Group

“…[12] Because of their inherent electrophilicity, most of the known phosphenium salts (R 2 P ϩ ) feature two π-donor substituents such as amino groups. [13] Notable exceptions are the (amino)(mesityl)- [14] and (phosphanyl)(supermesityl)-phosphenium [15] salts, which both feature an electron-rich [ aryl substituent. Given the potential uses of phosphenium salts as strong π-acceptor ligands, [16] it was of interest to investigate the possibility of preparing a phosphenium salt featuring an electron-withdrawing group.…”