title: An anionic phosphenium complex as an ambident nucleophile.
abstract: A unique anionic phosphenium complex was prepared from reaction of an N-heterocyclic chlorophosphine with Collman's reagent or K[HFe(CO)4]/NaH and characterized by spectral and XRD data. The complex behaves as an ambident nucleophile. Reactions with acetic acid, ClSnPh3, and a further equivalent of an N-heterocyclic chlorophosphine proceed via electrophilic functionalization at the metal site to yield appropriate mono- or bis-phosphenium complexes. Reaction with MeI at -70 °C produces a P-alkylation product as the first spectroscopically detectable intermediate, which decays at a higher temperature to give a mixture of free P-methylated N-heterocyclic phosphine and its Fe(CO)4 complex. The different reaction products were characterized by spectral and XRD data. Computational studies indicate that the NHP units in all complexes display π-acceptor behaviour but show no disposition to adopt phosphide-like character or formally oxidize the metal centre.
authors.affiliation: Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70550 Stuttgart, Germany. gudat@iac.uni-stuttgart.de.
authors.forename: B
authors.initials: B
authors.lastname: Stadelmann
authors.forename: J
authors.initials: J
authors.lastname: Bender
authors.forename: D
authors.initials: D
authors.lastname: Förster
authors.forename: W
authors.initials: W
authors.lastname: Frey
authors.forename: M
authors.initials: M
authors.lastname: Nieger
authors.forename: D
authors.initials: D
authors.lastname: Gudat