Vibrational spectra of solvent extracts: far-infrared spectra of gallium, indium, and thallium extracts from acidic chloride and bromide solutions

Abstract

Infrared spectra (500–195 cm.^–1) in di-isopropyl ether show bands due to the complex acids, HMX₄, formed on solvent extraction of Ga³⁺, In³⁺, and Tl³⁺ from HCl and HBr solutions, confirming previous Raman deductions. The tetrahalogeno-ions have T_d symmetry with the v₃ frequencies: GaCl₄^–= 374; GaBr₄^–= 274; InCl₄^–= 333; InBr₄^–= 233; TlCl₄^–= 293; TlBr₄^–= 197 cm.^–1. The same frequencies are found in crystalline tetramethylammonium salts of the bromo-ions and GaCl₄^– but the indium and thallium chloride complex salts have different spectra attributed to pentachloro-ions.