Abstract
A number of complexes CpFe(CO)2(L) (L = aldehyde, ketone, ester, amide) have been prepared either by treatment of [CpFe(CO)2]2 or CpFe(Co)2Br with AgPF6 in the presence of L or by a ligand exchange reaction employing CpFe(CO)2(isobutylene)BF4. NMR spectral data suggest that these complexes involve iron—oxygen σ-bonding rather than π-bonding to the carbonyl group. This is confirmed by an X-ray structure determination of the 3-methylcyclohexenone complex. The exchange stability of these complexes parallels their basicity.