pH-Dependent formation of three porous In(III)-MOFs: framework diversity and selective gas adsorption.

pH-Dependent self-assembly and structural transformation have been observed in a series of porous In(III)-MOFs, H 3 O[In 3 (pta) 4 (OH) 2 ]·10H 2 O (NXU-1), [In(pta) 2 ]·C 3 H 10 N (NXU-2) and [In(pta) 2 ]·C 3 H 10 N (NXU-3) (H 2 pta = 2-(4-pyridyl)-terephthalic acid). The structural diversities of NXU-1-3 reveal that the pH value of the reaction plays a key role in the assembly of In-MOFs. NXU-1 with excellent stability exhibits highly selective CO 2 adsorption over CH 4 as compared to NXU-2 and NXU-3, owing to the presence of abundant multiple active sites unveiled by theoretical calculations.