Halogen···Halogen Interactions in the Supramolecular Assembly of 2D Coordination Polymers and the CO2 Sorption Behavior

Abstract

Four new mixed-ligand divalent coordination polymers (CPs) [Cu2(muco)2(4-clpy)2] (1), [Cu2(muco)2(4-brpy)2] (2), [Zn2(bdc)2(4-clpy)2] (3), and [Zn2(bdc)2(4-brpy)2] (4) (H2muco = trans,trans-muconic acid or 1,3-butadiene-1,4-dicarboxylic acid; H2bdc = 1,4-benzene dicarboxylic acid; 4-clpy = 4-chloropyridine and 4-brpy = 4-bromopyridine) have been synthesized and well characterized by elemental analysis, infrared spectra, single-crystal X-ray diffraction techniques, powder X-ray diffraction patterns, and thermogravimetric analysis. All the compounds 1–4 have a two-dimensional (2D) coordination polymeric sheet structure. Of these, 1 and 2 are isotypical and form a 3D supramolecular aggregation based on type-I halogen–halogen interactions (Cl···Cl or Br···Br) and have an impact on CO2 sorption properties. For the first time, halogen–halogen interactions have been used as a tool in the construction of high-dimensional CPs for sorption studies. However, analogous compounds 3 and 4 are expanded to 3D supramolecu...