Assignment of ν2 (E) and ν4 (F2) of tetrahedral species by the calculation of the relative Raman intensities: The vibrational spectra of VO43−, CrO42−, MoO42−, WO42−, MnO4−, TcO4−, ReO4−, RuO4, and OsO4

A new method has been developed to assign the frequencies ν2(E) and ν4(F2) in tetrahedral molecules and ions. The method employs the calculation of the relative Raman intensities and has been applied to VO43−, CrO42−, MoO42−, WO42−, MnO4−, TcO4−, ReO4−, RuO4, and OsO4. The assignment of the frequencies has been further confirmed by measuring the infrared and Raman spectra of some of the ions and molecules in the same solvent. A more complete spectrum of TcO4− than earlier reported in the literature has been given.