Vibrational spectroscopic studies on ion–molecule interactions in non-aqueous solvents. Part 1.—Far infrared studies on tetra-n-butylammonium chloride in benzene

Abstract

The far infrared absorption of solutions of tetra-n-butylammonium chloride in benzene has been examined as a function of concentration and temperature. Part of the absorption (both for liquid and solid solutions) arises from severely perturbed benzene molecules which must, therefore, be involved in “solvation” of ion aggregates. The whole spectrum is thought to arise from vibrations of the solvated, or maybe solvent separated, ion aggregates and from the collisions of severely polarised benzene molecules. The benzene perturbation is further reflected by the intensity enhancement of the ν₁₆(e_2u) band. The concentration dependence of the band intensity shows clearly that the ion aggregates are “breaking up” as the concentration is lowered.