Raman spectroscopic investigations of concentrated aqueous solutions of InCl3 and of InBr3

Abstract

Raman spectra have been observed for concentrated solutions of indium chloride and bromide in water and deuterium oxide. Isotopic shifts and the modification of these profiles were observed for the Raman bands at ca. 400 cm^–1, 195 cm^–1, 60–80 cm^–1 in indium bromide, and ca. 400 cm^–1, 295 cm^–1, 90–120 cm^–1 in indium chloride solutions. When the static pressure of the solution increases from 1 atmosphere up to ca. 6 kbar the value of the frequency of the 195 cm^–1 Raman band increases and a small modification of the profile of the spectrum of the ca. 4 mol dm^–3 indium bromide solution is observed in the region near 40 cm^–1. Indium complexes with a quasi-linear configuration (halide–indium–halide) seem to be the predominant species existent in these concentrated solutions; the presence of coordinated water molecules in these complexes is apparent.