Multinuclear solid-state nuclear magnetic resonance studies on transition-metal clusters containing hydrides

Solid-state H-1 and D NMR measurements have been made for all transition-metal carbonyl clusters containing interstitial hydrides/deuterides previously characterised by neutron diffraction. There is a close agreement between the values of delta(H-1/D) in solution and the solid state except for [Co6H(CO)(15)](-). The values of delta(H-1) for interstitial hydrides are in the range delta + 18.5 to -26.8; the shift to high field is shown to be due to an increasing displacement of H from the centre of the metal octahedral cavity, consistent with surface tensor harmonic theory. Whereas migration of H readily occurs in both [Rh13Hx(CO)(24)]((5-x)-) (x = 2 or 3) and [Ru2Rh2H2(CO)(12)] in solution, solid-state H-1 NMR measurements on [Rh13Hx(CO)(24)]((5-x)-) (x = 2 or 3) showed that there is no evidence for such migration in the solid state and for [Ru2Rh2H2(CO)(12)] oscillation of H about the metal-metal edge(s) occurs rather than migration to different edges as found in solution.