Reaction of a manganese(iii)-Schiff base complex with gadolinium nitrate: synthesis, structure and magnetic properties of an ionic species [LMn(H2O)2]2[Gd(NO3)5(MeOH)] (H2L = 1,3-bis((3-methoxysalicylidene)amino)-2,2′-dimethylpropane)

Abstract

The crystal structure of an ionic entity formulated {[LMn(H₂O)₂]₂[Gd(NO₃)₅(MeOH)]} resulting from the reaction of a manganese(III) Schiff-base complex (H₂L = 1,3-bis((3-methoxysalicylidene)amino)-2,2′-dimethylpropane) with Gd(NO₃)₃·5H₂O has been determined. The manganese(III) ion exhibits an octahedral geometry where the basal plane involves the N₂O₂ 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.