From the same supramolecular framework to distinct types of porous liquids via in-situ transformation

Porous liquids (PLs), integrating porous hosts into flowing liquids through intermolecular interactions, attract significant attention, while their controlled synthesis remains challenging. Here we report a controllable in-situ transformation strategy to fabricate distinct types of PLs from the same supramolecular framework (SMF). Two isomorphic polyethylene-glycol-based ionic liquids, IL-Br and IL-NTf2, differing only in anions, exhibit contrasting electrostatic interactions with the SMF. Strong attraction between IL-Br and the SMF disrupts the ionic bonds within the framework, yielding a type II PL, PL2(SMF-Br), while electrostatic repulsion in IL-NTf2 preserves the framework, producing a type III PL, PL3(SMF-NTf2). These tailored host–solvent interactions endow PL2(SMF-Br) with over twice the CO2 uptake and photoresponsivity of its counterpart, as well as record-high CO2 capacity among reported type II PLs. In this work, we establish a general strategy for tunable PL construction through electrostatically guided host–solvent design. Porous liquids show potential as material for carbon dioxide capture but their controlled synthesis remains challenging. Here the authors report a controlled in-situ transformation strategy to fabricate distinct types of porous liquids from one type of supramolecular framework.