Syntheses, Crystal Structures, and Magnetic Properties of Metal-Organic Hybrid Materials of Mn(II)/Co(II): Three-Fold Interpenetrated α-Polonium-like Network in One of Them

Three new 1,4-phenylenediacrylate bridged Mn(II) and Co(II) complexes of molecular formulas {[Mn-2(ppda)(phen)(4)(H2O)(2)](ppda)(2)(H2O)} (1), {[Co(ppda)(dpyo)(H2O)(3)]center dot 4(H2O)}(n) (2), and {[Co(ppda)(bpe)]center dot(0.5H(2)O)}(n) (3) [ppda = 1,4-phenylenediacrylate; phen = 1,10-phenanthroline; dpyo = 4,4'-dipyridyl N,N'-dioxide; bpe = 1,2-bis(4-pyridyl)ethane] have been synthesized and characterized by elemental analysis, IR spectra, single-crystal X-ray diffraction studies, and low-temperature magnetic measurements. The structural determination reveals that complex 1 is a discrete dinuclear species, 2 is a ID polymeric chain, while 3 is a three-fold interpenetrated alpha-polonium network. Hydrogen-bonding interactions, formed by coordinated and/or lattice water molecules with ppda oxygen and pi-pi stacking interactions of aromatic rings, lead to a 3D supramolecular architecture in both complexes 1 and 2. Low-temperature magnetic study shows antiferromagnetic coupling in all the complexes. In addition, their electronic and fluorescent spectral properties have been investigated.