Photochemical reactivity of group 9 metal pinacolate complexes

Citation
Aw. Holland et al., Photochemical reactivity of group 9 metal pinacolate complexes, ORGANOMETAL, 20(11), 2001, pp. 2250-2261
Citations number
43
Categorie Soggetti
Organic Chemistry/Polymer Science
Journal title
ORGANOMETALLICS
ISSN journal
02767333 → ACNP
Volume
20
Issue
11
Year of publication
2001
Pages
2250 - 2261
Database
ISI
SICI code
0276-7333(20010528)20:11<2250:PROG9M>2.0.ZU;2-Y
Abstract
Coordinatively unsaturated pentameehylcyclopentadienyl pinacolate complexes of the group 9 transition metals (4-6) have been prepared and characterize d. Photolysis of either the cobalt complex 4 or the rhodium complex 5 resul ts in cleavage of the central carbon-carbon bond in the diolate, generating acetone. Various trapping studies demonstrate that an intact [Cp*M] fragme nt is produced in these reactions, and in the absence of added traps this f ragment reacts either with aromatic solvents or with an intact molecule of the starting pinacolate complex. The oxidation of the resulting rhodium(II) product II by air (or Oz) in the presence of pinacol regenerates the rhodi um(III) pinacolate complex 5. Photolysis of rhodium complex 5 in the presen ce of pinacol and oxidant (either O-2 or N2O) results in the catalytic conv ersion of pinacol to acetone.