Vibrational analysis of the H4I2O102− ion in CuH4I2O10·6H2O

Vibrational wavenumbers (IR and Raman) have been calculated for the diperiodate ion H₄I₂O₁₀²⁻ on the basis of a DFT method and assigned to experimental wavenumbers obtained from CuH₄I₂O₁₀·6H₂O. To obtain vibrational wavenumbers in the range comparable to the experiment it was necessary to use the complex (H₄I₂O₁₀)₇(Cu(H₂O)₆)₆]²⁻. Smaller complexes lead to much too high wavenumbers for the O‐H stretching vibrations and to too small wavenumbers in the range of the internal vibrations of the anion. On the basis of the results of the calculations an assignment of the Raman lines observed for CuH₄I₂O₁₀· 6H₂O to the vibrational modes is given. Copyright © 2008 John Wiley & Sons, Ltd.