Figure 1.

(a) Representative structure of the metal–organic framework Mg₂(dobpdc). Green, red, gray, and white spheres represent Mg, O, C, and H atoms, respectively. The inset shows a single open Mg^II site appended with a diamine molecule. (b) Depiction of cooperative CO₂ insertion into a row of Mg^II–diamine sites to form ammonium carbamate chains along the pore axis. The threshold conditions for cooperative adsorption can be tuned by modifying the diamine structure to adjust the strength of the metal–amine bond and the ammonium carbamate ion-pairing interaction.