Synthesis of a Highly Porous Bis(imino)pyridine-Linked Polymer and Its Postsynthetic Modification with Inorganic Fluorinated Ions for Selective CO2 Capture

A novel bis(imino)pyridine-linked porous polymer with high BET surface area of 1580 m(2) g(-1) was synthesized via a facile condensation reaction between 2,6-pyridinedicarboxaldehyde and 1,3,5-tris(4-aminophenyl)benzene. The polymer was postsynthetically functionalized with Cu(BF4)(2) through the complexation of copper cations with bis(imino)pyridine moieties of the polymer, where BF4 ions act as counterions to balance the charge of copper cations. The effect of functionalization on CO2 uptake capacity and selectivity was studied. The functionalization resulted in a 19% enhancement in CO2 binding affinity and 200% increase in CO2 uptake capacity at 0.15 bar. Upon functionalization, CO2/N-2 and CO2/CH4 selectivity values increased by a factor of up to 6. The functionalized network exhibits high CO2/N-2 and CO2/CH4 selectivity values of 101 and 20, respectively.