Oxidation of Organometallic Platinum and Palladium Complexes Obtained from C−H Activation

η^3-Cyclohexenyl and -indenyl Pt(II) and Pd(II) diimine complexes, which are generated via C−H activation of cyclohexene and indene by Pt and Pd hydroxy dimers, are selectively oxidized by Br_2, Na_2PtCl_6, and CuCl_2 to give halogenated organic products along with well-defined Pd(II) and Pt(II) species

C−H Bond Activation by Air-Stable [(Diimine)M^(II)(μ_2-OH)]_2^(2+)Dimers (M = Pd, Pt)

Air- and water-tolerant C−H activation is observed in reactions of [(diimine)Pt(μ_2-OH)]_2^(2+) dimers with allylic and benzylic C−H groups. The reactions proceed in good yields under mild conditions. Mechanistic studies indicate that the active species is the monomeric [(diimine)Pt(OH_2)]^(2+) dication. The related palladium species, [(diimine)Pd(μ_2-OH)_2]^(2+), exhibit similar stoichiometric activations and also effect catalytic oxidation of cyclohexene to benzene with molecular oxygen as the terminal oxidant

Dinitrogen Complexes Supported by Tris(phosphino)silyl Ligands

The tetradentate tris(phosphino)silyl ligand [Si^P(iPr)_3] ([SiP^(iPr)_3] = [Si(o-C_6H_4P^(iPr)_2)_3]−) has been prepared, and its complexation with iron, cobalt, nickel, and iridium precursors has been explored. Several coordination complexes have been thoroughly characterized and are described. These include, for example, the divalent trigonal bipyramidal metal chlorides [SiP^(iPr)_3]M−Cl (M = Fe, Co, Ni), as well as the monovalent dinitrogen adducts [SiP^(iPr)_3]M−N_2 (M = Fe, Co, Ir), which are compared with related [SiP^(Ph)_3]M−Cl and [SiP^(Ph)_3]M−N_2 species (M = Fe, Co). Complexes of this type represent the first examples of terminal dinitrogen adducts of monovalent iron, and the ligand architecture allows examination of a unique class of dinitrogen adducts with a trans-disposed silyl donor. Oxidation of the appropriate [SiP^(R)_3]M−N_2 precursors affords the divalent iron triflate [SiP^(Ph)_3]Fe(OTf) and trivalent cobalt triflate {[SiP^(iPr)_3]Co(OTf)}{OTf} complexes, which are of interest for group transfer studies because of the presence of a labile triflate ligand. Comparative electrochemical, structural, and spectroscopic data are provided for these complexes