Reaction of a manganese(III)-Schiff base complex with gadolinium nitrate: synthesis, structure and magnetic properties of an ionic species [LMn(H_2O)_2]_2[Gd(NO_3)_5(MeOH)](H_2L = 1,3-bis((3-methoxysalicylidene)amino)-2,2'-dimethylpropane)

摘要

The crystal structure of an ionic entity formulated {[LMn(H_2O)_2]_2[Gd(NO_3)_5(MeOH)]} resulting from the reaction of a manganese (III) Schiff-base complex (H_2L = 1,3-bis((3-methoxysalicylidene)amino)-2,2'-dimethylpropane) with Gd(NO_3)_3·5H_2O has been determined. The manganese(III) ion exhibits an octahedral geometry where the basal plane involves the N_2O_2 inner donor set of the Schiff base and the apical positions are occupied by the water oxygen atoms. The gadolinium(III) ion is ten-coordinate to four bidentate nitrate groups, one monodentate nitrate group and one methanol oxygen atom. As expected from the structural data, the magnetic study confirms the absence of Mn … Mn and Mn … Gd interactions. Indeed the metal ions are separated by large distances without any material support between them. The Mn~(III) ZFS, which is the only active parameter, has to be taken into account to fit the experimental data at low temperature (D = -4.58 cm~(-1)). The negative sign is in agreement with the tetragonal elongation of the manganese environment.