Occurrence of slow relaxation of the magnetization in a family of copper(II)/manganese(II) quasi-isotropic complexes with different ground spin states.

A family of copper(II)/manganese(II) new clusters with the formulas [CuNa(L2)(MeOH)(ClO)] (1), [CuII2Mn(,-L3)(MeOH)](ClO) (2SS), [{CuMn(L1)(HO)(MeOH)}{Cu(L1)}](ClO) (3), [(μ-N){CuMn(L2)(HO)}{Cu(L2)](ClO)} (4) and [(μ-N){CuMn(L1)(N)}{CuNa(L1)(MeOH)}](ClO) (5) with L1 = ,'-ethylene-bis(3-methoxysalicylaldiimine), L2 = ,'-ethylene-bis(3-ethoxysalicylaldiimine) and L3 = ,'-cyclohexane-bis(3-ethoxysalicylaldiimine), has been synthesized, and structurally and magnetically characterized. Reduced magnetization studies demonstrate that the magnetic anisotropy of the systems is very small. However, dynamic magnetic studies and ultra-low-frequency Raman spectroscopy confirm the slow relaxation of these systems despite their quasi-isotropic nature, enlarging the range of non-anisotropic slow relaxing molecules.