Using a bis-triazolate ligand and tetrahedral Zn(II) ion, we synthesized a flexible porous coordination polymer functionalized with pairs of uncoordinated triazolate N-donors that can be used as guest chelating sites to give very high CO2 adsorption enthalpy and CO2/N-2 selectivity. The dynamic CO2 sorption behavior could be monitored well by single-crystal X-ray diffraction.