Synthesis, Crystal Structures, and Magnetic Properties of MnII, CoII, and ZnII Coordination Polymers Containing 1,2,4,5-Benzenetetracarboxylic Acid and 4,4′-Azobispyridine

Manganese(II), cobalt(II), and zinc(II) coordination polymers, {[Mn(H(2)btec)(azopy)(H2O)(2)]center dot(azopy)}(n) (1), {[Co(H(2)btec)(azopy)-(H2O)(2)]center dot(azopy)}(n) (2), and {[Zn-2.5(btec)(azopy)(mu(3)-OH)-(H2O)]center dot H2O}(n) (3) (H(4)btec = 1,2,4,5-benzenetetracarboxylic acid; azopy = 4,4'-azobispyridine), were synthesized by a hydrothermal method and characterized by single-crystal X-ray diffraction, elemental analysis, and powder X-ray diffraction. Compounds 1 and 2 are isomorphic and crystallize in the triclinic space group P (1) over bar, exhibiting a 2D grid framework bridged by two types of ligands. Compound 3 also crystallizes in the triclinic space group Pi and possess an interesting 3D coordination framework with an unprecedented dodecadentate coordination mode and a unique {4(16).5(10).6(18).7}{4(4).5.6}(2) topological structure. The ideal topology of 3 has not been encountered in metal-organic framework chemistry, which has been deposited in the Reticular Chemistry Structure Resource under the name zim net. Magnetic studies show that there are antiferromagnetic interactions in both 1 and 2. The cyclic voltammograms of 1-3 in the solid state were also obtained.