Porous Metal‐Organic Cages Based on Rigid Bicyclo[2.2.2]oct‐7‐ene Type Ligands: Synthesis, Structure, and Gas Uptake Properties

Abstract

Three new ligands containing a bicyclo[2.2.2]oct‐7‐ene‐2,3,5,6‐tetracarboxydiimide unit have been used to assemble lantern‐type metal‐organic cages with the general formula [Cu4L4]. Functionalisation of the backbone of the ligands leads to distinct crystal packing motifs between the three cages, as observed with single‐crystal X‐ray diffraction. The three cages vary in their gas sorption behaviour, and the capacity of the materials for CO2 is found to depend on the activation conditions: softer activation conditions lead to superior uptake, and one of the cages displays the highest BET surface area found for lantern‐type cages so far.

A metal–organic cage with light-switchable motifs for controllable CO2 adsorption

“…In contrast, there is no obvious CO 2 uptake change for Zr-MC-1 upon visible and UV light irradiation. In addition, in comparison to some previously reported MOCs, NUT-102 offers advantages in terms of CO 2 adsorption capacity (Table S2†), 18,50–59 as well as exhibiting light-switchable CO 2 adsorption behavior.…”

Improving the gas sorption capacity in lantern-type metal–organic polyhedra by a scrambled cage method

“…The ligands LH 2 , CH 3 LH 2 , and MeOLH 2 were synthesised following previously reported procedures. 54,56 The solvent content provided is based on the analysis of TGA data and NMR digestions for [Cu 4 (MeOL) 4− x (CH 3 L) x ] ( x = 1, 2, 3) as the solvent could not be refined in the diffraction data; and on the single-crystal X-ray diffraction data for [Cu 4 (L) 4− x (CH 3 L) x ] ( x = 0, 1, 2, 3), where solvent was refined.…”

“…1 ). 54 The homoleptic lantern [Cu 4 (CH 3 L) 4 ] was found to display the highest Brunauer–Emmett–Teller (BET) surface area for lantern cages, as derived from the N 2 sorption isotherm. Herein, we target the formation of scrambled cages by using mixtures of the ligands LH 2 , CH 3 LH 2 , and MeOLH 2 ( Fig.…”