HYDRIDO-1,5-CYCLOOCTADIENEIRIDIUM(III) COMPLEXES STABILIZED BY TRICHLOROSTANNATE LIGANDS AND THE STRUCTURE OF

Article abstract of DOI:10.1016/0022-328X(85)87122-9

The complexes , and , L = tertiary arylphosphine, have been isolated and characterized by 1H, 31P and 119Sn NMR spectroscopy.The coordinated 1,5-COD ligand is stable with respect to insertion into an iridium-hydride bond at room temperature, in contrast to the cationic complexes ⁺ which are known to react rapidly at this temperature.The complexes exist as cis,cis- and cis,trans- (L trans to SnCl3^-) isomers in solution. is a poor hydrogenation catalyst for the olefin styrene, cyclohexene and 1,5-COD at room temperature in CH2Cl2.The structure of has been determined by crystallographic methods.The three phosphines are in a pseudo-meridional arrangement and the two hydrides are cis to one another.The phosphine ligands are displaced toward the hydrido ligands relative to their position in a typical octahedral complex.Relevant bond lengths (Angstroem) and bond angles (deg) are as follows: Ir-Sn, 2.623(1); Ir-P, 2.318(4), 2.340(4), 2.395(3) (with the latter for P trans to H); Sn-Ir-P, 97.54(10), 97.35(9), 99.97(9); P-Ir-P, 102.11(12), 105.21(11), 145.95(9) (P trans to P).The hydride ligands have been located at a distance of ca. 1.7 Angstroem from the metal.