CO2 Adsorption in SIFSIX-14-Cu-i: High Performance, Inflected Isotherms, and Water-Triggered Release via Reversible Structural Transformation: CO2 Adsorption in SIFSIX-14-Cu-i: High Performance, Inflected Isotherms, and Water-Triggered Release via Reversible Structural Transformation

SIFSIX-14-Cu-i belongs to a family of metal-organic materials (MOMs) with exciting gas-sorption properties and high technological impact. CO2-adsorption isotherms are reported for SIFSIX-14-Cu-i revealing very high uptake combined with CO2 selectivity. Importantly, the isotherms show distinct inflection points that result from CO2-induced structural transformations and that can be modulated by the CO2 uptake quantity. The observed behaviour directly relates to the unique structure of this azopyridine-stabilised compound and gives rise to the highest known working capacity for CO2 uptake between 0.1 and 1 bar. Furthermore, the synthetic procedures for the reversible transformation of SIFSIX-14-Cu-i to a non-porous hydrated form are highlighted, and exploit the reversible porous to non-porous phase transition for instantaneous, moisture-mediated CO2 release.