Abstract
The Raman spectra of p‐benzoquinone, quinone‐d4, quinone‐18O2, quinone‐d418O2, and quinone‐2,5‐d2, excited by the helium radiation 5875.6 Å, are reported, together with semiquantitative measurements of the intensities and qualitative observations on the state of polarization of the Raman shifts. The results are fully consistent with the D2h symmetry of the four molecular species mentioned first, the last one belonging to the point group C2h. A tentative assignment for all Raman‐active fundamental vibrational modes of the investigated compounds is given.