Changing the Dress to a MOF through Fluorination and Transmetalation. Structural and Gas-Sorption Effects

Two novel pillared Zn(II)-based Metal-Organic Frameworks were de novo synthesized exploiting N,N'-(1,1'-biphenyl)-4,4'-diylbis-4-pyridinecarboxamide (bpba) and its fluorinated analogous N,N'-(perfluoro-1,1'-biphenyl-4,4'-diyl)diisonicotinamide (F-bpba) as suitable pillar linkers and 2,6-naphthalene dicarboxylic acid as carboxylic ligand. The resulting heteroleptic MOFs, namely, PUM210, [Zn-4(bpba)(1.5)center dot(ndc)(4)center dot(H2O)](n) and PUM210F, [Zn-3(F-bpba)(1)center dot(ndc)(3)center dot(DMF)](n), feature an uncommon truncation of the Zn(II) paddle-wheel nodes along the pillaring direction. PUM210 and PUM210F exhibit a polycatenated architecture, resulting in microporous channels decorated by amide moieties. The activated forms show a permanent porosity and a selective adsorption of CO2 over N-2. Moreover, the partially transmetalated Cu-PUM210 and Cu-PUM210F were obtained by convenient transmetalation protocol and their adsorption propriety toward CO2 were subsequently investigated.