Syntheses and structural characterization of transition metal(II) coordination polymers containing 4,4′-dipyridyldisulfide

The reactions of Zn(NO3)2 · 6H2O and FeSO4 · 7H2O with 4-PDS (4-PDS = 4,4′-dipyridyldisulfide) and NH4SCN in CH3OH afforded the complexes [Zn(NCS)2(4-PDS)]n (1) and [Fe(NCS)2(4-PDS)2 · 4H2O]n (2), respectively, while the reaction of CoCl2 · 6H2O with 4-PDS in CH3OH gave the complex {[Co(4-PDS)2][Cl]2 · 2CH3OH}n, (3). These complexes have been characterized by spectroscopic methods and their structures determined by X-ray crystallography. The 4-PDS ligands in 1 are coordinated to the metal centers through the nitrogen atoms to form 1-D zigzag-chains, and the distorted tetrahedral coordination geometry at each zinc center is completed by a pair of N-bonded thiocyanate ligands. Compound 2 has a 1-D channel-chain structure and each octahedral Fe(II) metal center is coordinated by four 4-PDS ligands and two trans N-bonded thiocyanate ligands. Weak S⋯S interactions in complex 1 link the 1-D chains into 2-D molecular sheets. In complex 2, the channel chains are interlinked through S⋯S interactions to form molecular sheets, which interpenetrate through the S⋯S interactions to form 3-D structures with large cavities that are occupied by the water molecules. Compound 3 also has a 1-D channel-chain structure with each square-planar Co(II) metal center coordinated by four 4-PDS ligands. Multiple C–H⋯Cl hydrogen bonds and S⋯O interactions in 3 link the 1-D chains into 2-D structures.

Graphical abstractThe synthesis and structures of three new coordination polymers, Zn(NCS)2(4-PDS)]n(4-PDS = 4,4′-dipyridyldisulfide) (1), [Fe(NCS)2(4-PDS)2 · 4H2O]n (2), and {[Co(4-PDS)2][Cl]2 · 2CH3OH}n (3), are reported. Complex 1 exibits 1-D zigzag-chains, while complexes 2 and 3 shows 1-D channel chains structures.Figure optionsDownload full-size imageDownload as PowerPoint slide