Rationalizing the CO2 vs. N2O selectivity switch triggered by linker-composition modulation in a metal-organic framework via in situ high-re

CO2 and N2O are concerning greenhouse gases in the atmosphere, triggering the identification of adsorbents designed ad hoc for their capture. The metal-organic framework [Ce6O4(OH)4(TzTz)6] (Ce1; TzTz = [2,2'-bithiazole]-5,5'-dicarboxylate) shows a higher capacity, thermodynamic affinity (Qst,CO2 = 18.2 kJ/mol, Qst,N2O = 25.4 kJ/mol) and selectivity S (S N2O/CO2 = 1.6 at 273 K) for N2O. [Ce6O4(OH)4(TzTz)4(PyPy)2] (Ce2; PyPy = 2,2'-bipyridine-5,5'-dicarboxylate), having the same 3D architecture, shows a higher capacity, affinity (Qst,CO2 = 29.5 kJ/mol, Qst,N2O = 26.4 kJ/mol) and selectivity (S CO2/N2O = 1.4 at 298 K) for CO2. DFT calculations on the [N2O@Ce1] and [CO2@Ce2] systems unveiled Ce···N2O and TzTz···CO2 interactions. HR-PXRD in situ dosing CO2 and N2O (0.1-1 bar, 273 and 298 K) will provide otherwise inaccessible crystallochemical and thermodynamic details for this case study and new-generation adsorbents discriminating polluting gases via linker-composition modulation.