The vibrational spectra of a number of trinuclear complexes ([M3O(OAc)6]+(M = Cr, Fe, Ru), [Cr3O(HCO2)6]+, [(ClHg)3O]+, [Ir3O(SO4)9]10–, [Ru3O2(NH3)14]6+, and [Ru3O2(NH3)14]7+, and the tetranuclear complex Zn4O(OAc)6 have been studied. The structures of the complexes in the solid and solution states are discussed on the basis of these results.