A new 8-connected porous coordination polymer: crystal structure and selective adsorption properties

A new coordination polymer associated with cobalt ion, [Co-3(Tda)(3)(bpp)(2)].2DMF (1, Tda = thiophene-2,5-dicarboxylic acid, bpp 1,3-bis(4-pyridyl) propane, DMF = dimethylformamide), was prepared under solvothermal conditions, and characterized by the single-crystal X-ray diffraction, element analysis, and IR spectra. Each Tda is coordinated to four Co-II ions with mu(4)-kappa O : kO' : kO '', kO'''-mu(2) coordination mode and each bpp ligand is ligated to two Co-II ions with anti-anti bridging mode in 1. Each cobalt(II) trimer is connected to eight adjacent Co-3 units via four Tda and four bpp ligands reduced to a uninodal 8-connected topology. Sorption studies conducted on this permanently microporous material imply that it can separate carbon dioxide from nitrogen and methane with high selectivity.