Tuning CO2 Uptake and Reversible Iodine Adsorption in Two Isoreticular MOFs through Ligand Functionalization

Abstract The synthesis and characterization of two isoreticular metal–organic frameworks (MOFs), {[Cd(bdc)(4‐bpmh)]} n ⋅2 n (H 2 O) ( 1 ) and {[Cd(2‐NH 2 bdc)(4‐bpmh)]} n ⋅2 n (H 2 O) ( 2 ) [bdc=benzene dicarboxylic acid; 2‐NH 2 bdc=2‐amino benzene dicarboxylic acid; 4‐bpmh= N , N ‐bis‐pyridin‐4‐ylmethylene‐hydrazine], are reported. Both compounds possess similar two‐fold interpenetrated 3D frameworks bridged by dicarboxylates and a 4‐bpmh linker. The 2D Cd‐dicarboxylate layers are extended along the a‐ axis to form distorted square grids which are further pillared by 4‐bpmh linkers to result in a 3D pillared‐bilayer interpenetrated framework. Gas adsorption studies demonstrate that the amino‐functionalized MOF 2 shows high selectivity for CO 2 (8.4 wt % 273 K and 7.0 wt % 298 K) over CH 4 , and the uptake amounts are almost double that of non‐functional MOF 1 . Iodine (I 2 ) adsorption studies reveal that amino‐functionalized MOF 2 exhibits a faster I 2 adsorption rate and controlled delivery of I 2 over the non‐functionalized homolog 1 .