Structural and stereochemical studies on reactive iridium(III) dihydride complexes of the triphosphine ligand C 6H 5P[CH 2CH 2CH 2P(C 6H 11) 2] 2

Abstract

The iridium(III) dihydride complexes IrH 2X- (Cyttp) (X = Cl, I) possess a mer-octahedral structure in which the hydrides are cis to each other and the Cyttp ligand is chelated around an edge of the octahedron. The phenyl group on the central phosphorus atom is oriented away from the chloride ligand in the crystal structure, and Nuclear Overhauser Effect (NOE) measurements show that this anti coordination geometry is maintained in solution. Treatment of IrH 2Cl(Cyttp), 1a, with TIBF 4 and CH 3CN results in a mixture of anti and syn diastereomers, whereas CO gives only the syn diastereomer of the type [IrH 2(CH 3CN)(Cyttp)] + and Tl +.