1D Coordination Polymers from Zinc(II) and Cadmium(II) Halides and 2,2′-Dithiobis(pyridine N-oxide): Isostructurality and Structural Diversity

Group 12 halides and 2,2′-dithiobis(pyridine N-oxide) (dtpo) form the crystalline the 1D coordination polymers [ZnX2(μ-dtpo-κ2O:O′)]n [X = Cl (1), Br (2), I (3)], [Cd3(μ-Cl)4Cl2(μ-dtpo-κ2O:O′)2(CH3OH)2]n (4), [(CdBr2)2(μ3-dtpo-κ3O,O:O′)2(H2O)2]n (5), and [(CdI2)2(μ-dtpo-κ2O:O′)3]n (6) in methanol. The compounds were structurally characterized by single-crystal X-ray analysis. Compounds 1–3 represent an isomorphous series of single-stranded coordination polymers, whereas the CdII derivatives are structurally diverse. The metal nodes in 4 and 5 are trinuclear and dinuclear cadmium clusters, respectively. In 4 and 5, the metal nodes are linked into double-stranded 1D coordination polymers by two dtpo bridging ligands. Compound 6 contains mononuclear CdI2 units as nodes and can be viewed as an alternating copolymer of CdI2(μ-dtpo-κ2O:O′)2 and CdI2(μ-dtpo-κ2O:O′) entities. Owing to the disulfide moiety, the dtpo bridging ligand inevitably exhibits an axially chiral angular structure. The dtpo ligand adopts various coordination modes through the pyridine N-oxide oxygen atoms.