Three manganese(II)N-oxide complexes have been synthesized from the reaction of manganese(II) chloride with either pyridineN-oxide (PNO), 2-methylpyridineN-oxide (2MePNO) or 3-methylpyridineN-oxide (3MePNO). The compounds were synthesized from methanolic solutions of MnCl2·4H2O and the respectiveN-oxide, and subsequently characterized structurally by single-crystal X-ray diffraction. The compounds arecatena-poly[[aquachloridomanganese(II)]-di-μ-chlorido-[aquachloridomanganese(II)]-bis(μ-pyridineN-oxide)], [MnCl2(C5H5NO)(H2O)]nor [MnCl2(PNO)(H2O)]n(I),catena-poly[[aquachloridomanganese(II)]-di-μ-chlorido-[aquachloridomanganese(II)]-bis(μ-2-methylpyridineN-oxide)], [MnCl2(C6H7NO)(H2O)]nor [MnCl2(2MePNO)(H2O)]n(II), and bis(μ-3-methylpyridineN-oxide)bis[diaquadichloridomanganese(II)], [Mn2Cl4(C6H7NO)2(H2O)4] or [MnCl2(3MePNO)(H2O)2]2(III). The MnIIatoms are found in pseudo-octahedral environments for each of the three complexes. CompoundIforms a coordination polymer with alternating pairs of bridgingN-oxide and chloride ligands. The coordination environment is defined by two PNO bridging O atoms, two chloride bridging atoms, a terminal chloride, and a terminal water. CompoundIIalso forms a coordination polymer with a similar metal cation; however, the coordination polymer is bridged between MnIIatoms by both a single chloride and 2MePNO. The distorted octahedrally coordinated metal cation is defined by two bridging 2MePNOtransto each other, two chlorides, alsotransto one another in the equatorial (polymeric) plane, and a terminal chloride and terminal water. Finally, complexIIIforms a dimer with two bridging 3MePNOs, two terminal chlorides and two terminal waters forming the six-coordinate metal environment. All three compounds exhibit hydrogen bonding between the coordinating water(s) and terminal chlorides.
Analysis of energies of halogen and hydrogen bonding interactions in the solid state structures of vanadyl Schiff base complexes