Porous Metal–Organic Frameworks with Chelating Multiamine Sites for Selective Adsorption and Chemical Conversion of Carbon Dioxide

A combination of carbon dioxide (CO 2 ) capture and chemical fixation in a one-step process is attractive for chemists and environmentalists. In this work, by incorporating chelating multiamine sites to enhance the binding affinity toward CO 2, two novel metal–organic frameworks (MOFs) [Zn 2 (L)(2,6-NDC) 2 (H 2 O)]·1.5DMF·2H 2 O ( 1 ) and [Cd 2 (L)(2,6-NDC) 2 ]·1.5DMF·2H 2 O ( 2 ) (L = N 1 -(4-(1 H -1,2,4-triazole-1-yl)benzyl)- N 1 -(2-aminoethyl)ethane-1,2-diamine, 2,6-H 2 NDC = 2,6-naphthalenedicarboxylic acid, DMF = N, N -dimethylformamide) were achieved under solvothermal conditions. Both 1 and 2 possess high selectivity for adsorption of CO 2 over CH 4 at room temperature under atmospheric pressure. Moreover, 1 has one-dimensional tubular channels decorated with multiactive sites including NH 2 groups and coordination unsaturated Lewis acid metal sites, leading to efficient catalytic activity for chemical fixation of CO 2 by reaction with epoxides to give cyclic carbonates under mild conditions.