Raman spectrum of the [SnI3]− ion and other halogenostannate(II) complexes including mixed halides

Abstract

AbstractThe complete Raman spectrum of the pyramidal triiodostannate(II) ion [SnI3]− (ν1 = 162 cm−, strong, polarized; ν2 = 61 cm−, medium, polarized; ν3 = 148 cm−, strong, depolarized; ν4 = 48 cm−, strong, depolarized) is observed in a diethyl ether extract from a solution of tin(II) iodide containing hydriodic acid. Previous reports of the frequencies of [SnCl3]− are confirmed but for [SnBr3]− ν1 is revised from 211 to 205 cm−1. The complex acids H[SnX2Y] and H[SnXYZ] (X, Y or Z = Cl, Br or I) are observed in solvent extracts of tin(II) mixed halide solutions and a set of ν(Sn—halogen) frequencies is compiled. Appreciable co‐extraction of [SnX2(H2O)] occurs at halogen acid concentrations below 3 mol l−1.