Ni(II) Coordination Polymers Constructed from the Flexible Tetracarboxylic Acid and Different N-Donor Ligands: Structural Diversity and Catalytic Activity

Abstract

To seek the effect that condition of the complexes has on the manufacture of the biaryl compounds, seven Ni(II) complexes, namely, {[Ni(L)0.5(bpa)(H2O)]·2H2O}n (1), {[Ni2(L)(dpp)2(H2O)]·4H2O}n (2), {[Ni(L)0.5(pbmb)(H2O)]·H2O}n (3), {[Ni2(L)(bmp)2(H2O)]·7H2O}n (4), {[Ni(L)0.5(pbib)1.5]·2H2O}n (5), {[Ni2(L)(pbib)1.5]·3H2O}n (6), and [Ni(L)0.5(beb)2(H2O)]n (7) (bpa = 1,2-bis(4-pyridyl)ethane, dpp = 1,3-di(4-pyridyl)propane, pbmb = 1,1′-(1,3-propane)bis(2-methylbenzimidazole), bmp = 1,5-bis(2-methylbenzimidazol) pentane, pbib = 1,4-bis(imidazol-1-ylmethyl)benzene, beb = 1,4-bis(2-ethylbenzimidazol-1-ylmethyl)benzene), have been gained through hydro(solvo)thermal reactions of 5,5′-(hexane-1,6-diyl)-bis(oxy)diisophthalic acid ligand (H4L) with Ni(II) metal ions under the regulation and control of six N-donor ligands. 3-fold interpenetrating complex 1 belongs to a (4,4)-connected 3D bbf net with a vertex symbol of (64·82)(66) topology. 3-fold interpenetrating complex 2 presents a (4,4,4)-connected 3D bbf net with a Schläfli symbol of (66)2(64·82) topology. 3 features a (3,4)-connected 3,4L13 topology with a Schläfli symbol of (4·62)(42·62·82) topology. 4 possesses a (4,4,4)-connected mog Moganite 3D network fabric, and the vertex symbol is (4·64·8)2(42·62·82). 5 takes on a (4,5)-connected architecture, and the point symbol is (4·69)(42·66·82). 6 is a (4,7)-connected framework, and the Schläfli symbol is (45·5)(47·53·611). 7 has a (4,4)-connected 4,4L28 topology, and the point (Schläfli) symbol is (42·64)(4·64·8). A systematic structural comparison of 1–7 signifies that their frameworks can be regulated through varied conformations of the flexible H4L ligand and diverse N-donor ligands. Between the proximal Ni(II) ions, the variable-temperature (2–300 K) magnetic susceptibilities of 6 display overall weak antiferromagnetic coupling. In the complexes-catalyzed homocoupling reaction of iodobenzene, 3, 5, 6, and 7 have been verified to be effectual catalysts for the synthesis of the biaryl compounds.