13C NMR studies on tricarbonylchromium complexes of dimethylaminofulvene and diphenylfulvene

The 13C NMR spectra of tricarbonylchromium complexes of dimethylaminofulvene diphenylfulvene have been studied. Comparison of the 13C NMR spectra of these complexes with those of the corresponding non-coordinated fulvenes shows that the contribution from the ylidic structure of the π-ligand in the first complex increases when the Cr atom becomes coordinated, while in the second complex this coordination does not favour a formation of the ylidic structure of the π-ligand.