Solvation of cobalt(II) and trifluoromethanesulfonate ions in N,N-dimethylformamide–methanol mixed solvent studied by means of FT-IR spectroscopy

FT-IR spectra of Co(CF3SO3)2–N,N-dimethylformamide (DMF)–methanol (MeOH) solutions have been measured over the whole range of solvent composition. The data together with the obtained previously spectra of DMF–MeOH mixtures have been analyzed using the difference spectra method in the region of CO and OH stretching bands. The number of DMF and MeOH molecules in the first solvation sphere of Co(II) ion versus solvent composition has been determined. The second solvation sphere has been revealed and characterized quantitatively. Solvation of trifluoromethanesulfonate (triflate) ion as well as ion association in DMF solution have been also studied.