Syntheses and crystal structures of three one-dimensional copper(II) complexes constructed by salicylate and 4,4′-bipyridine: Ladder, zig-zag, and linear polymeric assembly

Syntheses and crystal structures of three new compounds {trans-[Cu(Hsal)₂(4,4′-bipy)](DMF)}_n (1), {cis-[Cu(Hsal)₂(4,4′-bipy)](2H₂O)}_n (2), and [Cu₂(Hsal)₄(4,4′-bipy)]_n (3) are reported. These three compounds have trans-, cis-, and dimer geometries bearing a common motif [Cu(Hsal)₂(4,4-bipy)_n] leading to ladder, zig-zag, and linear one-dimensional (1-D) networks, respectively. The CuCu distances separated by 4,4′-bipy are different in these three compounds, which leads to an extension structure in compound 3 and a compact structure in compound 2. Conformations of 4,4′-bipy ligands in these three compounds are also different. In compound 1 there is stacking of the bidentate salicylate and the bridging salicylate from another molecule. There is also stacking of salicylate and 4,4′-bipy from another molecule in compound 2.