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

The reaction of salicylaldoxime, tetracarboxylate btca4− with MnCl2·4H2O resulted in the isolation of a novel coordination polymer with (4,4)-net based on oximate-bridged Mn(III) clusters, namely, {Na2[MnIII6O2(sao)6(btca)(H2O)2]·5H2O}n (1) (H2sao = 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 btca4− and Na+ bridges and this 2D net is extended to 3D frameworks through π–π stacking between the phenyl rings of the sao2− 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.