Tetrazole-based porous metal–organic frameworks for selective CO2 adsorption and isomerization studies. Issue 7 (29th January 2020) - Zhang, Rui
Abstract : Tetrazole-based porous MOFs and isomers were synthesized for adsorbing carbon dioxide, showing high selectivity. Abstract : Tetrazole-based molecules have numerous bridging coordination modes which afford great synthetic possibilities for the preparation of porous metal-tetrazolate architectures for many applications, such as carbon capture. We reported here three tetrazole-based MOFs: 1, {[Cu12 (ttz)8/3 Cl5 (H2 O)16 ] 11+ ·11Cl − } n (H3 ttz = N 2, N 4, N 6 -tris(4-(1 H -tetrazol-5-yl)phenyl)-1, 3, 5-triazine-2, 4, 6-triamine), contains highly positively charged Cu12 clusters and the largest mesopores (32 Å) among the reported MOFs based on a tri-topic tetrazole ligand. 2 and 3 are two MOF isomers built by using Cu II and 2-(1 H -tetrazol-5-yl)pyrimidine. 3 contains nonporous layers, while 2 contains 1D channels and showed high selectivity for adsorbing CO2, which should be attributed to the high density of free nucleophilic tetrazole N atoms on the pore surfaces. We found that the isomerization between 2 and 3 was caused by the diverse coordination modes of tetrazole-based ligands and can be controlled in synthesis processes.