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

Abstract

The reactions of Zn(NO 3) 2 · 6H 2O and FeSO 4 · 7H 2O with 4-PDS (4-PDS = 4,4′-dipyridyldisulfide) and NH 4SCN in CH 3OH afforded the complexes [Zn(NCS) 2(4-PDS)] n ( 1) and [Fe(NCS) 2(4-PDS) 2 · 4H 2O] n ( 2), respectively, while the reaction of CoCl 2 · 6H 2O with 4-PDS in CH 3OH gave the complex {[Co(4-PDS) 2][Cl] 2 · 2CH 3OH} 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.