Carbon-13 and proton magnetic resonance spectra of cyclopentadienylcycloheptatrienylmetal compounds

Abstract

Carbon-13 and proton magnetic resonance spectra of the compounds (C 5H 5)M(C 7H 7) (M = tt, Zr, Mo, Cr) and of some methyl derivatives of the Ti compound have been studied. In the Ti and Zr compounds the C-13 resonance of the C 7H 7 ring is observed to higher field than that of the C 5H 5 ring; the opposite applies to the Cr compound, while for the Mo compound the two signals lie close together. This is taken to indicate that the C 7H 7 ring is more negatively charged than the C 5H 5 ring in the Ti and Zr compounds, while the reverse is true for the Cr compound; these results agree with those of metallation experiments. Proton magnetic resonance spectra indicate hindered rotation of the rings in the Cr and Mo compounds, but not in the Ti and Zr compounds.