Electron spin relaxation and hyperfine line shape of manganese (II) in mixed-solvent systems

The X-band ESR line shape of the six hyperfine components of manganese (II) has been investigated both in pure and in mixed solvents. The procedure used by Luckhurst and Pedulli [G. R. Luckhurst and G. F. Pedulli, Mol. Phys. 22, 931 (1971)] to account for the removal of the spin degeneracy by the nonsecular terms in the spin Hamiltonian has been used to compute the line shape as a function of (D:D) and of τc. In mixed solvents, large deviations from the theoretical line shape are due to the presence of differently coordinated complexes. A criterion for the determination of the selective solvation has been established.