Single‐crystal‐to‐single‐crystal transformation of a two‐dimensional noninterpenetrated layer to a microporous three‐dimensional fourfold interpenetrated MOF triggered by DMF

Abstract

We have demonstrated a single‐crystal‐to‐single‐crystal (SCSC) transformation from a two‐dimensional noninterpenetrated layer to a microporous three‐dimensional fourfold interpenetrated MOF. The centrosymmetric [Co2(μ2‐OH)(EIBA)3]n (SNUT‐25) transforms into a microporous [Co(EIBA)2]n (SNUT‐26), which is triggered by the reaction time with DMF that acts as a structure‐directing agent (HEIBA = 4‐(2‐ethyl‐1H‐imidazol‐1‐yl)benzoic acid; DMF = N,N′‐dimethylformamide). Despite the distinct structure and coordination arrangements of SNUT‐25 in contrast to SNUT‐26, both Co‐MOFs were synthesized using the same ligand. Fascinatingly, upon introducing a specific quantity of DMF combined with a negligible proportion of nitric acid, SNUT‐25 will progressively and completely transform into SNUT‐26. Under the synergistic induction of solvent molecules and temperature, SNUT‐25 changed from the original two‐dimensional layered structure to the three‐dimensional pore structure of SNUT‐26. In addition, SNUT‐25 and SNUT‐26 are efficient photocatalysts for the degradation of organic dye methyl blue (MB) under visible light irradiation. Surprisingly, the degradation rates of both SNUT‐25 and SNUT‐26 can reach over 96%. In addition, SNUT‐25 and SNUT‐26 also exhibited high electrocatalytic oxygen evolution reaction.