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

Solid-state 1H 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 δ(1H/D) in solution and the solid state except for [Co6H(CO)15]–. The values of δ(1H) for interstitial hydrides are in the range δ+ 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 1H 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.