title: Isolation and structural characterization of anionic and neutral compounds resulting from the oxidative addition of HI or CH3I to [IrI2(CO)2](-).
abstract: The active iridium species in the methanol carbonylation reaction has been crystallized as the [PPN][IrI(2)(CO)(2)] complex and the X-ray structure solved, showing a cis-geometry and a square planar environment. Hydriodic acid reacts very quickly with this compound to provide [PPN][IrHI(3)(CO)(2)], the X-ray crystal structure of which has been determined. The two CO ligands remain in mutual cis-position in a pseudooctahedral environment. The same cis-arrangement has been observed from the X-ray structure for [PPN][IrI(3)(CH(3))(CO)(2)] resulting from the slower oxidative addition of CH(3)I to [PPN][IrI(2)(CO)(2)]. By iodide abstraction with InI(3), the anionic methyl complex gave rise to the dimeric neutral complex [Ir(2)(mu-I)(2)I(2)(CH(3))(2)(CO)(4)]. An X-ray structure showed that the methyl ligands are in the equatorial positions of the two octahedrons sharing an edge, formed by the two bridging iodide ligands. All these four complexes have been fully characterized by mass spectrometry, (1)H and (13)C NMR, and infrared both in solution and in the solid state. When necessary, the (13)CO- or (13)CH(3)-enriched complexes have been prepared and analyzed.
authors.affiliation: Laboratoire de Catalyse, Chimie Fine et Polymères, Ecole Nationale Supérieure des Ingénieurs en Arts Chimiques et Technologiques, 118 route de Narbonne, 31077 Toulouse Cedex 4, France.
authors.forename: Samuel
authors.initials: S
authors.lastname: Gautron
authors.forename: Roberto
authors.initials: R
authors.lastname: Giordano
authors.forename: Carole
authors.initials: C
authors.lastname: Le Berre
authors.forename: Joël
authors.initials: J
authors.lastname: Jaud
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Daran
authors.forename: Philippe
authors.initials: P
authors.lastname: Serp
authors.forename: Philippe
authors.initials: P
authors.lastname: Kalck