Zinc(II) and Cadmium(II) Complexes with Rigid 3,3′,5,5′-Tetra(1H-imidazol-1-yl)-1,1′-biphenyl and Varied Carboxylate Ligands

Six new coordination polymers [Zn­(L)0.5(CO3)]·H2O (1), [Zn­(L)0.5(DC)]·H2O (2), [Cd­(L)0.5(DC)]
(3), [Cd­(L)0.5(PBEA)]·H2O
(4), [Cd2(L)­(MBEA)2]·4H2O (5), and [Zn­(L)0.5(MBEA)]·2H2O (6) with different structures and topologies
were successfully synthesized by hydrothermal reactions of zinc­(II)/cadmium­(II)
salts with rigid ligand 3,3′,5,5′-tetra­(1H-imidazol-1-yl)-1,1′-biphenyl
(L) and auxiliary multicarboxylic acids of 1,3,5-tri­(4-carboxyphenyl)­benzene
(H3BTB), 1,4-benzenediacrylic acid (H2DC), 1,4-benzenediacetic
acid (H2PBEA), and 1,3-benzenediacetic acid (H2MBEA), respectively. Carbonate anion, rather than the carboxylate
anion of H3BTB, is incorporated in 1. Complexes 1 and 5 are (4,4)- and (4,6)-connected binodal
two-dimensional (2D) networks with a point (Schläfli) symbol
of (4.64.8)2(42.64) and
(32.42.52)­(34.44.54.63), respectively. Complex 2 is a self-penetrating three-dimensional (3D) framework with a point
(Schläfli) symbol of (62.84)­(64.82)2, while 3 shows a (3,4,5)-connected
trinodal 3D framework with a point (Schläfli) symbol of (4.63.86)2(42.84)­(63)2. The 3-fold interpenetrating net of 4 is a subnet of sta with a point (Schläfli) symbol
of (4.64.8)2(42.62.82), while the net of 6 is vested in nbo set net with a point (Schläfli) symbol of (64)­(82). The results show that the auxiliary ligands and metal centers
play important roles in the formation of complexes with diverse structures.
Furthermore, the thermal stability, photoluminescence, and sorption
properties of the complexes were investigated.