Synthesis, structural analysis, and magnetic properties of ethylmalonate-manganese(II) complexes.

Five manganese(II) complexes of formulas [Mn2(Etmal)2(H2O)2(L)]n (1–4) and {[Mn(Etmal)2(H2O)][Mn(H2O)4]}n (5) with H2Etmal = ethylmalonic acid (1–5) and L = 1,2-bis(4-pyridyl)ethane (bpa) (1), 4,4′-azobispyridine (azpy) (2), 4,4′-bipyridyl (4,4′-bpy) (3), and 1,2-bis(4-pyridyl)ethylene (bpe) (4) were synthesized and structurally characterized by single crystal X-ray diffraction. Their thermal behavior and variable-temperature magnetic properties were also investigated. The structure of the compounds 1–4 consists of corrugated layers of aquamanganese(II) units with intralayer carboxylate-ethylmalonate bridges in the anti-syn (equatorial-equatorial) coordination mode which are linked through bis-monodentate bpa (1), azpy (2), 4,4′-bpy (3), and bpe (4) ligands to build up a three-dimensional (3D) framework. The structure of compound 5 is made up by zigzag chains of manganese(II) ions with a regular alternation of [Mn(H2O)4]2+ and chiral (either Δ or λ enantiomeric forms) [Mn(Etmal)2(H2O)]2– units within each...