Vibrational Spectra of Eight‐Coordinate Niobium and Tantalum Complexes with Peroxo Ligands: A Theoretical Simulation

A theoretical interpretation of the experimental observations made by vibrational IR and Raman spectroscopy on eight‐coordinate peroxo complexes of niobium( V ) and tantalum( V ) is carried out. The theoretical study, realised on stoichiometric models of general formula [M(O 2 ) 4 ] 3– , [M(O 2 ) 3 L 2 ] x – , cis ‐ and trans ‐[M(O 2 ) 2 L 4 ] y – and [M(O 2 )L 6 ] z – (M = Nb V or Ta V ), provides the normal modes of vibrations involving peroxo ligands, their corresponding calculated frequency and their activity in IR and/or Raman spectroscopy. The theoretical results from the model complexes are compared with experimental IR and Raman spectroscopic data. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)