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, H3O[In-3(pta)(4)(OH)(2)]center dot 10H(2)O (NXU-1), [In(pta)(2)]center dot C3H10N (NXU-2) and [In(pta)(2)]center dot C3H10N (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 CO2 adsorption over CH4 as compared to NXU-2 and NXU-3, owing to the presence of abundant multiple active sites unveiled by theoretical calculations.