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

A new coordination polymer associated with cobalt ion, [Co3(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 CoII ions with µ4-κO : κO′ : κO″,κO‴-µ2 coordination mode and each bpp ligand is ligated to two CoII ions with anti–anti bridging mode in 1. Each cobalt(II) trimer is connected to eight adjacent Co3 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.