Porous Organic Salts: Diversifying Void Structures and Environments.

Porous organic salts (POSs) are porous organic materials, in which various aromatic sulfonic acids and amines are regularly self-assembled by charge-assisted hydrogen bonding. POSs exhibit high solubility in highly polar solvents. Therefore, they are prepared via facile recrystallization and exhibit high recyclability. In this study, tetrahedral-structured tetrasulfonic acid and triphenylmethylamine (TPMA) were combined to construct POSs with rigid diamond networks called diamondoid porous organic salts (d-POSs). Furthermore, by introducing substituents (e.g., F, Cl, Br, or I) at the para-positions of benzene rings of TPMA, these substituents were exposed on the void surface of d-POSs, and their diamond networks were distorted. This induced the formation of a variety of void structures and environments in the d-POSs, which significantly affected their gas adsorption behavior. In particular, the d-POS from TPMA substituted by fluorine exhibited very high CO2 adsorption of 182 mL(STP) g-1 at 1 atm in all-organic porous materials.