Synthesis, characterization and crystal structures of 2D Co(II)/Zn(II)-coordination polymers containing 3-(pyridin-4-yl)-5-(pyrazin-2-yl) -1H-1,2,4-triazole and benzenetetracarboxylate co-ligands

Under solvothermal condition, the reaction of Co(II) or Zn(II) acetate with mixed-ligands 3-(pyridin-4-yl)-5-(pyrazin-2-yl)-1H-1,2,4-triazole (Hppt) and 1,2,4,5-benzenetetracarboxylate (H₄btec) affords two isomorphic compounds [M(btec)_0.5(Hppt)]_n (M = Co(II) (1), Zn(II) (2)), which display the same dinodal (4,4)-connected 2D net. In addition to single-crystal X-ray crystallography, the complexes are also characterized by IR spectroscopy, PXRD, thermogravimetry, and elemental analysis. Magnetic susceptibility measurements indicate that domain antiferromagnetic interaction exists between Co(II) ions, and the paramagnetic behavior in 1 can be observed. The fluorescent property of 2 has been investigated in the solid state at room temperature.