The porous nature of these mixed-ligand materials has been analysed using N2 sorption measurements, revealing some differences depending on the combination of ligands. Thus, whereas ZIF-8-mimb and ZIF-8-eimi show BET values of 875 and 845 m 2 /g, respectively (Figure ), in agreement with previous reports, ZIF-8-eimb shows a negligible N2 sorption capacity. On the contrary, for the Co(II) compounds, only ZIF-67-eimi presents remarkable porosity, albeit lower than the Zn(II) analogue (BET of 402 m 2 /g, Figure ), whereas the two mixedligand Fe(II) materials present a negligible N2 sorption capacity. This seems to be the result of a smaller window caused by the bulkier ligand combined with a different gate-opening capacity depending on the metal, as previously hypothesized. These textural properties are also accompanied by a higher stability towards water, improving their chemical stability (see Section S4 in the Supporting Information). For example, the mixedligands Fe(II) materials (MUV-3-mimb and MUV-3-eimb) are stable for more than two days in humid atmosphere, whereas the pure ligand MUV-3 decomposes in a few hours in non-inert conditions.