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

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-[aqua-manganese(II)]-μ₂-acetato-μ-(pyridine N-oxide)-manganese(II)-μ₃-acetato-μ₂-acetato-μ-(pyridine N-oxide)-[aqua-manganese(II)]-di-μ₂-acetato], [Mn₄(CH₃COO)₈(C₅H₅NO)₂(H₂O)₂] , (I), catena-poly[[manganese(II)]-μ₃-acetato-μ₂-acetato-μ-(2-methyl-pyridine N-oxide)-[aqua-manganese(II)]-di-μ₂-acetato-manganese(II)-di-μ₂-acetato-μ₃-acetato-[aqua-manganese(II)]-μ₂-acetato-μ-(2-methyl-pyridine N-oxide)], [Mn₄(CH₃COO)₈(C₆H₇NO)₂(H₂O)₂] , (II), and catena-poly[[manganese(II)-di-μ₂-acetato-μ-(4-methyl-pyridine N-oxide)] monohydrate], {[Mn(CH₃COO)₂(C₆H₇NO)]·H₂O} , (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-octa-hedral six-coordinate mangan-ese(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-methyl-pyridine N-oxide (2MePNO), or 4-methyl-pyridine 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 mol-ecule forms bridging hydrogen bonds between two neighboring acetates. In compound (III) a water mol-ecule of solvation is found in the lattice, not bound to the metal ion but hydrogen bonding to a bridging acetate.