An Electron Paramagnetic Resonance Study of Mn(II)-Chloro Complex Formation in Ν,Ν-Dimethylformamide

Abstract

EPR spectra differing in hyperfine splitting have been reported for Mn (II) ions in Ν,Ν-Dimethylformamide (DMF) when using Mn (ClO4) 2 and MnCl2. The difference in the reported spectra is shown to be due to the species MnCl4 2⊖ by a mole ratio plot. The presence of MnCl⊕ is also indicated by a mole ratio plot. Three basic spectra, differing in hyperfine splitting, are obtained for solutions of Mn (ClO4) 2 in DMF to which varying amounts of chloride ion have been added. ΔH° for the equilibrium reaction of the species Mn2⊕ und MnCl⊕ was determined from the variation of the formation constant, Kc, with temperature over the range 25° to 116°C. Values for ΔF° and ΔS° at 25°C are also given.