Figure 5: NMR studies.

(a) 1H NMR spectra (benzene-d6, hydride region) of catalyst precursor 3 (I, 300.1 MHz), amido complex 9 (II, 300.1 MHz) and dihydride 8 (III, 400.1 MHz); (b) 31P{1H }NMR spectra (benzene-d6) of catalyst precursor 3 (I, 121.0 MHz), amido complex 9 (II, 121.0 MHz, residual coupling to hydride hydrogens is present) and dihydride 8 (III, 161.9 MHz).