A two-dimensional coordination polymer constructed from hexanuclear manganese units with sodium ions as auxiliary bridges

摘要

The reaction of salicylaldoxime, tetracarboxylate btca~(4-) with MnCl_2·4H_2O resulted in the isolation of a novel coordination polymer with (4,4)-net based on oximate-bridged Mn(III) clusters, namely, {Na_2[Mn~III_6O_2(sao)_6(btca)(H_2O)_2]·5H_2O}_n (1) (H_2sao = salicylaldoxime and H4btca= 1,2,3,4-butane tetracarboxylate acid). The complex was characterized by single crystal X-ray diffraction, IR spectroscopy, elemental analysis and magnetic measurements. Structural analysis reveals that complex 1 is a 2D net formed by linking Mn6 clusters through btca~(4-) and Na~+ bridges and this 2D net is extended to 3D frameworks through π-π stacking between the phenyl rings of the sao~(2-) ligands and hydrogen bonding interactions. Low temperature magnetic studies indicate that complex 1 displays slow magnetic relaxation and antiferromagnetic coupling dominates in the Mn6 unit.