Published May 1990 | Version v1
Journal article

Kinetic deuterium isotope effects on ligand migrations in metal hydrides

  • 1. California State Univ., Northridge (USA)
  • 2. Universita di Torino (Italy)

Description

Variable-temperature (VT) 1H and 13C NMR studies of the complexes (μ-X)2Os3(CO)9(μ3-η2-(CH3CH2)2C2) (X = H or D) reveal that alkyne migration over the face of the cluster is directly linked to hydride migrations on the metal core as evidenced by a temperature-independent isotope effect (kHH/kDD = 1.7). In a related study of the VT 13C NMR of (μ-X)2M3(CO)9(μ3-S) (X = H or D; M = Ru, Os) the observation of a kHH/kDD = 1.6 for both the osmium and ruthenium complexes demonstrates that the first stage of carbonyl averaging is brought about by hydride migration and not axial-radial exchange of carbonyl groups, a process that occurs only at higher temperatures. The mechanistic implications of these results are discussed in the context of the reactivity of metal clusters and the dynamic properties of the metal-hydrogen bond

Additional details

Publishing Information

Journal Title
Organometallics
Journal Volume
9
Journal Issue
5
Series
Organometallics.
Journal Page Range
1379-1382
ISSN
0276-7333
CODEN
ORGND