DIENE AND DIENYL COMPLEXES OF TRANSITION ELEMENTS II. THE PROTONATION OF η-DIARYLDIENONE(η-CYCLOPENTADIENYL)-RHODIUM(I) AND -IRIDIUM(I) COMPLEXES

Article abstract of DOI:10.1016/S0022-328X(00)83475-0

Reaction of 4-PhCH=CRCH=CHCOPh)(η⁵-C5H5)>, with HBF4 or HPF6 affords the crystalline salts 3-PhCHCRCHCH2COPh)(η⁵-C5H5)>Y, , in which the acyl CO group is coordinated to the metal.HCl and HBr also protonate the dienone complexes (M = Rh) at carbon, giving the covalent derivatives 3-PhCHCHCHCH2COPh)(η⁵-C5H5)>, .A mechanism involving endo addition of H⁺ to the η⁴-dienone ligand is in accord with deuteration studies. 1H and 13C NMR spectra of the new complexes are discussed.Thereactions of 4-PhCHCHCHCHPh)(η⁵-C5H5)> with HCl and HBr are also reported.