6533b855fe1ef96bd12b1524

RESEARCH PRODUCT

Solvent effects on the dimensionality of oxamato-bridged manganese(II) compounds

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Two new oxamate-containing manganese(II) complexes, [{Mn(H2edpba)(H2O)2}2]n (1) and [Mn(H2edpba)(dmso)2]∙dmso∙CH3COCH3∙H2O (2) (H4edpba = N,N′-ethylenediphenylenebis(oxamic acid) and dmso = dimethylsulfoxide), have been synthesized and the structures of 1 and 2 were characterized by single crystal X-ray diffraction. The structure of 1 consists of neutral honeycomb networks in which each manganese(II) is six-coordinate by one H2edpba2− ligand and two carboxylate–oxygens from two other H2edpba2− ligands building the equatorial plane. Each manganese is connected to its nearest neighbor through two carboxylate(monoprotonated oxamate) bridges in an anti-syn conformation. A dmso solution of single crystals of 1 was placed under acetone atmosphere affording 2, whereas putting 2 in equimolar water:ethanol mixture results in 1. The molecular structure of 2 is made up of mononuclear manganese(II) units which are interlinked by weak C–H⋯π and edge-to-face π-stacking interactions leading to supramolecular chains along the crystallographic b axis. Magnetic measurements reveal the occurrence of an antiferromagnetic coupling between two manganese(II) ions through anti-syn carboxylate bridges for 1 [J = −1.18 cm−1, the Hamiltonian being defined as H = −J S1.S2] and very weak intrachain ferromagnetic interactions in 2 [J = + 0.046 cm−1, H = −J ∑iSi.Si + 1].