Self-assembly of a new “4,4′-bipyridyl-based” building block with Cd(II) and Co(II) cations: synthesis and crystal structures of 1- and 2-D coordination polymers

We synthesized a new “4,4′-bipyridyl-based” building block, 1,4-(di-4-pyridyl) methoxy benzene (bpmob), which appears as two kinds of isomers: trans- and cis-modes. The building block self-assembled into one-dimensional coordination polymer [Cd(NO3)2(cis-bpmob)2]n·[Cd(NO3)2(trans-bpmob)(H2O)]2n (I) with Cd(II), and two-dimensional coordination polymer [Co(NCS)2(trans-bpmob)2]n (II) with Co(II). Polymer I consists of two parts: double zig-zag linear chain and ladder-like one-dimensional chain, trans- and cis-modes exist simultaneously in the polymer. Polymer II shows a two-dimensional plane network structure with rhombohedral grids, and the polymer also exhibits layered packing in its solid-state structure.