Electronic absorption spectra of nickel dichloride and nickel oxide solutions in the 2CsCl-NaCl and KCl-NaCl metls

The electronic absorption spectra of nickel dichloride and nickel oxide dilute solutions in the 2CsCl-NaCl and KCl-NaCl melts have been measured by ultraviolet reflection absorption spectroscopy in the range 250–2500 nm. The spectroscopic data demonstrate the formation of stable Ni(II)-based tetrahedral groups (NiCl42−) in solutions of nickel dichloride in the 2CsCl-NaCl melt, whereas in the KCl-NaCl melt, nickel dichloride undergoes thermal dissociation to give Ni(II)-and Ni(I)-based complex groups: NiCl42−, NiCl64−, and NiCl43−. The dissolution of nickel oxide in the 2CsCl-NaCl and KCl-NaCl melts gives mainly NiOCl33− complex groups.