title: Chelate and pincer carbene complexes of rhodium and platinum derived from hexaphenylcarbodiphosphorane, Ph3P=C=PPh3.
abstract: The reaction of [(cod)RhCl]2 with Ph3P=C=PPh3 (1) gave the bidentate Rh(I) carbene complex, (cod)Rh[eta2-C{P(C6H4)Ph2}{PPh3}] (2), in which one of the Ph groups in 1 underwent orthometalation to form the chelate. Displacement of cod by 2 equiv of PMe3 transformed 2, via a second orthometalation event, into the Rh(III) C,C,C pincer carbene complex, HRh(PMe3)2[eta3-C{P(C6H4)Ph2}2] (3). The reaction of [Me2Pt(SMe2)]2 with 1 led directly to the analogous C,C,C pincer carbene complex of Pt(II), (Me2S)Pt[eta3-C{P(C6H4)Ph2}2] (4). DFT calculations on a model form of 3 suggest a net single sigma-bonding interaction between Rh and an sp2-hybridized carbene center, with a HOMO that is predominantly carbene pz in character.
authors.affiliation: Department of Chemistry, Graduate School of Science, Hiroshima University, Higashi-Hiroshima, 739-8526 Japan.
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Kubo
authors.forename: Nathan D
authors.initials: ND
authors.lastname: Jones
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Ferguson
authors.forename: Robert
authors.initials: R
authors.lastname: McDonald
authors.forename: Ronald G
authors.initials: RG
authors.lastname: Cavell