Infrared Spectra of Highly Associated Liquids and the Question of Complex Ions in Fused Salts

Infrared absorption spectra have been derived from infrared reflectivity data by the method of Robinson and Price for the systems LiNO3–NaNO3, KNO3–AgNO3, LiNO3–LiOH, LiNO3–H2O, LiClO3–H2O, LiOH–NaOH, ZnCl2–LiCl, ZnCl2–KCl, CuCl2–LiCl, CuCl2–KCl, and CuCl–LiCl. The question of the determination of the existence and nature of complex ions and ion-pairs in these strongly associated systems has been critically discussed and operational criteria have been suggested. In only one system studied (CuCl2–KCl) was the presence of a complex ion indicated by the spectroscopic data.