Syntheses, crystal structures, and catalytic properties of three zinc(II), nickel(II) and cobalt(II) coordination polymers constructed from 4,4-(pyridin-3,5-diyl)dibenzoic acid

Three zinc(II), nickel(II), and cobalt(II) coordination polymers, namely {[Zn(mu 3-pdba)(phen)]center dot H2O}n (1), {[Ni(mu(3)-pdba)(bipy)]center dot 3H(2)O}(n) (2), and {[Co(mu(3)-pdba)(H(2)biim)(H2O)]center dot H2O}(n) (3) have been constructed hydrothermally using 4, 4'-(pyridin-3, 5-diyl)dibenzoic acid (H(2)pdba), 1, 10-phenanthroline (phen), 2, 2 '-bipyridine (bipy), 2, 2 '-biimdazole (H(2)biim), and zinc, nickel and cobalt chlorides at 160 degrees C. The products were isolated as stable crystalline solids and were characterized by IR spectra, elemental analyses, thermogravimetric analyses, and single-crystal X-ray diffraction analyses. Single-crystal X-ray diffraction analyses reveal that the three compounds crystallize in the monoclinic system, space groups P2(1)/c or P2(1)/n. Compounds 1 and 2 show 2D networks. Compound 3 discloses a 1D ladder chain structure. The catalytic activities in the Henry reaction of these compounds were investigated. Compound 1 exhibited an effective catalytic activity in the Henry reaction at 70 degrees C. For this reaction, various parameters were optimized, followed by the investigation of the substrate scope.