Organometallics 1982, 1, 1567-1571 Under these conditions, less than 1% of the 1-hexene solvent was converted to n-hexane in a 24-h period at 25 “C. Hydrogen reacted with a benzene solution of (1,C3H5)Ir(04-COD) [P(OCH,),] to form propane, cyclooctane, and a new iridium complex. The ‘H NMR spectrum of this hydride consisted of a phosphite methoxy doublet resonance and a broad complex multiplet in the hydride region. All attempts to isolate the hydride in crystalline form failed; the hydride appeared to be a multinuclear iridium hydride, possibly analogous to the [HRhP(OR),],4 complexes. Both (03-C3H5)Ir[P(OCH3)3]3and (03-C3H5)Ir(04-1,5COD)[P(OCH,),] were active catalyst precursors for 1hexene hydrogenation to hexane (Table I). Isomerization of the 1-hexene to the cis- and trans-Zhexene and cis- and trans-3-hexene isomers was a significant (- 10%) competing process to olefin hydrogenation with the latter complex but not with the former (
