Raman spectroscopy of the heteronuclear complexes in the ZnCl2-CdCl2-Li,K/Cl and AlCl3-MgCl2-Li,K/Cl melts

The structure of the ZnCl2-CdCl2-Li,K/Cl and AlCl3-MgCl2-Li,K/Cl melts has been studied by Raman spectroscopy over a wide complexing metal concentration range. The spectroscopic criteria of heteronuclear-complex formation have been established: when the instability constants (or Gibbs energies) of the individual complex ions ZnCl42- and CdCl42- are close to each other, the nu(1) (A(l)) frequency disappears from the Raman spectra of these complexes, and a new Zn-Cl-Cd bond vibration line appears. When the stability characteristics of the individual complex ions AlCl4- and MgCl42- are different but high, a decrease in the vibration frequency and intensity of the MgCl42- complex due to a weakening of the Mg2+-Cl- bond is observed besides the appearance of a new Al-Cl-Mg bond vibration frequency in the Raman spectrum, (C) 1999 Elsevier Science B.V. All rights reserved.