Carboxylate-Free Manganese(II) Phosphonate Assemblies: Synthesis, Structure, and Magnetism

The reaction of manganese­(II) salts with organophosphonic acid [t-BuPO3H2 or cyclopentyl phosphonic acid (C5H9PO3H2)] in the presence of ancillary nitrogen ligands [1,10-phenanthroline (phen) or 2,6-bis­(pyrazol-3-yl)­pyridine (dpzpy)], afforded, depending on the stoichiometry of the reactants and the reaction conditions, dinuclear, trinuclear, and tetranuclear compounds, [Mn2(t-BuPO3H)4(phen)2]·2DMF (1), [Mn3(C5H9PO3)2(phen)6]­(ClO4)2·7CH3OH (2), [Mn3(t-BuPO3)2(dpzpy)3]­(ClO4)2·H2O (3), [Mn4(t-BuPO3)2(t-BuPO3H)2(phen)6(H2O)2]­(ClO4)2 (4), and [Mn4(C5H9PO3)2(phen)8(H2O)2]­(ClO4)4 (5). Magnetic studies on 1, 2, and 4 reveal that the phosphonate bridges mediate weak antiferromagnetic interactions between the MnII ions have also been carried out.