Synthesis, crystal structure, and magnetic characterization of two manganese Schiff-base-containing complexes

Resumo

The reactions of [Mn^III(3-MeOSalen)(H₂O)₂]⁺ (Salen = N,N-ethylenebis(salicylideneaminato) dianion) with (Et₄N)₄[M(CN)₈] (M = Mo, W) have been investigated and one mononuclear manganese(II) complex [Mn^II(Salen)(H₂O)] (I) and one bimetallic ion-pair complex [Mn^III(3-MeO-Salen)(H₂O)₂]₄[W(CN)₈] · DMSO · 4H₂O (II) were obtained unexpectedly and characterized by element and single crystal structure analysis. Single crystal X-ray diffraction (CIF files CCDC nos. 1456365 (I) and 1456366 (II)) showed that the Mn²⁺ ion in complex I is five-coordinated involving in a distorted square pyramid. Furthermore, with the help of the intermolecular hydrogen bond interactions, this complex can be constructed into interesting one-dimensional zig-zag chain structure. For complex II, the coordination sphere of Mn³⁺ ion is an elongated octahedron. Additional, the four mononuclear manganese(III) units are self-complementary through the coordinated aqua ligand from one molecule and the free O(4) compartment from the neighboring molecule, giving supramolecular dimmers structure. Investigation of the magnetic susceptibility of the two complexes reveals the overall weak antiferromagnetic interactions between the adjacent manganese centers caused by H-bond interactions.