NOVEL COMPLEXES OF RHODIUM AND IRIDIUM WITH ELECTRONEGATIVE OLEFINS

[Rh(CO)2Cl]2 undergoes halogen bridge splitting by triphenylphosphine to give trans-RhCl(CO)2(P(C6H5)3). Tetracyanoethylene (TCNE) forms a 1:1 adduct with this substrate, of the formula RhCl(CO)2(P(C6H5)8)(TCNE) (cis-dicarbonyl). cis-RhCl(CO)2(L) (L = pyridine, p-toluidine) forms adducts with TCNE and fumaronitrile (FMN) of the type RhCl(CO)2(L)(TCNE or FMN) (trans-dicarbonyl). IrCl(N2)(P(C6H5)3)2 reacts with TCNE to give [IrCl(P(C6H5)3)2(TCNE)] and with FMN to give both IrCl(N2)(P(C6H5)3)2(FMN) and IrCl(P(C6H5)3)2(FMN). In all these adducts the cyanoolefins are bonded to the metal through the olefinic bond. By the action of l,2-bis(diphenylphosphino)ethane (diphos), RhCl-(CO)2(L)(TCNE) is converted to [Rh(L)(diphos)(TCNE)]Cl whereas RhCl(CO)2(L)(FMN) gives [Rh(diphos)(CO)2]Cl. Infrared spectra, bonding modes, and reactivity are discussed. © 1969, American Chemical Society. All rights reserved.