The vibrational spectra of the halides, complex halides and mixed halides of thallium(III). Part I. The vibrational spectra of TlBr3, TlBr4, TlCl63– and TlCl4–
Abstract
The Raman spectrum of a solution of thallic bromide in ethanol to which lithium bromide has been added is compatible with the existence of the TlBr4 anion (symmetry Td). A number of other solutions containing this anion were also investigated. The i.r. and Raman spectra of solutions of thallic bromide in ethanol and in tri-n-butyl phosphate (TBP) indicate that these solutions consist of a mixture of TlBr3 and TlBr4–, and not the TlBr4– anion alone as reported previously. The Raman spectrum of a solution of thallic chloride in 1 OM-aqueous lithium chloride shows that this solution contains the TlCl63– anion, of point group Oh. The tri-n-butyl phosphate extract of this solution gives the Raman spectrum of the TlCl4– anion. A number of other solutions containing this anion are also investigated. The far-i.r. spectrum (20–400 cm.–1) of NEt4TlCl4 is also reported. Solutions of NEt4TlCl3Br and NEt4TlBr3Cl in acetonitrile are shown to consist of mixtures of the TlBr4– and TlCl4– anions.