The Raman spectra of complex anions of formula MX4 n? where M is Au III , Pt II , or Pd II , and X is a halogen atom

The Raman spectra of solid samples of the salts K2PtCl4, K2PtBr4, K2Ptl4, Na2Ptl4, K2PdCl4, K2PdBr4, KAuBr4, and KAul4 are reported. Agreement between the spectra recorded and those of aqueous solutions of the PtCl42– and AuBr4– anions is satisfactory in most respects suggesting that the phase does not seriously effect the vibration frequencies. The Raman and far-infrared spectra are assigned to fundamental modes of vibration. Force constants for the metal–halogen bonds are computed, compared, and discussed in relation to the stabilities and reactivities of these complex ions.