Structures of substituted pyridine N-oxide with manganese(II) acetate

Abstract

Manganese(II) acetate coordination polymers have been prepared with three derivatives of pyridine N-oxide. The compounds are catena-poly[manganese(II)-μ3-acetato-di-μ2-acetato-[aquamanganese(II)]-μ2-acetato-μ-(pyridine N-oxide)-manganese(II)-μ3-acetato-μ2-acetato-μ-(pyridine N-oxide)-[aquamanganese(II)]-di-μ2-acetato], [Mn4(CH3COO)8(C5H5NO)2(H2O)2]n, (I), catena-poly[[manganese(II)]-μ3-acetato-μ2-acetato-μ-(2-methylpyridine N-oxide)-[aquamanganese(II)]-di-μ2-acetato-manganese(II)-di-μ2-acetato-μ3-acetato-[aquamanganese(II)]-μ2-acetato-μ-(2-methylpyridine N-oxide)], [Mn4(CH3COO)8(C6H7NO)2(H2O)2]n, (II), and catena-poly[[manganese(II)-di-μ2-acetato-μ-(4-methylpyridine N-oxide)] monohydrate], {[Mn(CH3COO)2(C6H7NO)]·H2O}n, (III). Compounds (I) and (II) both have three unique Mn atoms; in both compounds two of them sit on a crystallographic inversion center while the third is on a general position. In compound (III), the single unique Mn atom sits on a general position. Pseudo-octahedral six-coordinate manganese(II) centers are found in all compounds. All of the compounds form chains of Mn atoms bridged by acetate ions and the oxygen atom of the N-oxide in pyridine N-oxide (PNO), 2-methylpyridine N-oxide (2MePNO), or 4-methylpyridine N-oxide (4MePNO). Compound (I) and (II) both exhibit a bound water of solvation. In (I), the water hydrogen bonds to a nearby acetate whereas in (II) the water molecule forms bridging hydrogen bonds between two neighboring acetates. In compound (III) a water molecule of solvation is found in the lattice, not bound to the metal ion but hydrogen bonding to a bridging acetate.

Keywords

• crystal structure
• manganese(II) acetate
• pyridine N-oxide ligand
• coordination polymer