Vibrational spectrum of π-allylmanganese tetracarbonyl

The i.r. and Raman spectra of (π-C3H5) Mn(CO)4 as a solid and in solution are reported and an assignment suggested. The vibrations of the allyl group are in good agreement with those in analogous molecules, and the vibrations of Mn(CO)4 must be discussed in terms of Cs, not C4v symmetry.