Fluorinated metal-organic frameworks: advantageous for higher H2 and CO2 adsorption or not?

The synthesis, structure, and gas adsorption properties of three new metal-organic frameworks (MOFs) designed from isonicotinic acid (INA) and its fluorinated analogue 3-fluoroisonicotinic acid (FINA) along with Co(II) as the metal center have been reported. Co-INA-1 ([Co(3)(INA)(4)(O)(C(2)H(5)OH)(3)][NO(3)]·C(2)H(5)OH·3H(2)O; INA=isonicotinic acid) and Co-INA-2 ([Co(INA)(2)]·DMF) are structural isomers as are Co-FINA-1 ([Co(3-)(FINA)(4)(O)(C(2) H(5) OH)(2)]·H(2)O; FINA=3-fluoroisonicotinic acid) and Co-FINA-2 ([Co(FINA)(2)]·H(2)O), but the most important thing to note here is that Co-INA-1 and Co-FINA-1 are isostructural as are Co-INA-2 and Co-FINA-2. The effect of partial introduction of fluorine atoms into the framework on the gas uptake properties of MOFs having similar structures has been analyzed experimentally and computationally in isostructural MOFs.