title: One-Electron Oxidation of [M(P(t) Bu3 )2 ] (M=Pd, Pt): Isolation of Monomeric [Pd(P(t) Bu3 )2 ](+) and Redox-Promoted C-H Bond Cyclometalation.
abstract: Oxidation of zero-valent phosphine complexes [M(P(t) Bu3 )2 ] (M=Pd, Pt) has been investigated in 1,2-difluorobenzene solution using cyclic voltammetry and subsequently using the ferrocenium cation as a chemical redox agent. In the case of palladium, a mononuclear paramagnetic Pd(I) derivative was readily isolated from solution and fully characterized (EPR, X-ray crystallography). While in situ electrochemical measurements are consistent with initial one-electron oxidation, the heavier congener undergoes C-H bond cyclometalation and ultimately affords the 14 valence-electron Pt(II) complex [Pt(κ(2) PC -P(t) Bu2 CMe2 CH2 )(P(t) Bu3 )](+) with concomitant formation of [Pt(P(t) Bu3 )2 H](+) .
authors.affiliation: Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, UK.
authors.forename: Thibault
authors.initials: T
authors.lastname: Troadec
authors.affiliation: Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, UK.
authors.forename: Sze-Yin
authors.identifier: http://orcid.org/0000-0002-3789-8745
authors.initials: SY
authors.lastname: Tan
authors.affiliation: Department of Physics, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, UK.
authors.forename: Christopher J
authors.identifier: http://orcid.org/0000-0002-3686-1043
authors.initials: CJ
authors.lastname: Wedge
authors.affiliation: Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, UK.
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Rourke
authors.affiliation: Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, UK.
authors.forename: Patrick R
authors.initials: PR
authors.lastname: Unwin
authors.affiliation: Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, UK. a.b.chaplin@warwick.ac.uk.
authors.forename: Adrian B
authors.identifier: http://orcid.org/0000-0003-4286-8791
authors.initials: AB
authors.lastname: Chaplin
keywords: C−H activation; oxidation; palladium; phosphane ligands; platinum