Anion solvation I. Solvation of the thiocyanate anion in aprotic solvents by near infrared spectroscopy

Solutions of tetrabutylammonium and lithium thiocyanates have been examined in the infrared 2000–5500 cm^?1 region at room temperature. New bands have been observed which can be assigned to simultaneous transitions between the v (CN) vibrations of the anion and the v (CH) vibrations of the solvent CH₃ group. These transitions which are independent of the state of association (free ion, ionpairs, dimers, triple cation) provide evidence of anion solvation by aprotic solvents.