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The uptake of iodine molecules (I2) is crucial when corresponding radioactive isotopes, implied in thyroid cancer, are released in nuclear power plants, or after nuclear accidents. The discovered material, made of molecular crystals formed by the stacking of Host-Guest complexes, possesses channels perfectly suited for iodine molecules even if these are preliminary filled by water molecules. This property is remarkable for uses in real conditions, as the energy saved for material synthesis and activation.
Reference :
Xue Yang, Chunyang Li, Michel Giorgi, Didier Siri, Xavier Bugaut, Bastien Chatelet, Didier Gigmes, Mehdi Yemloul, Virginie Hornebecq, Anthony Kermagoret, Sophie Brasselet, Alexandre Martinez, and David Bardelang , Angew. Chem. Int. Ed., 2022, DOI : 10.1002/anie.202214039.
Abstract :
Recently, porous organic crystals (POC) based on macrocycles have shown exceptional sorption and separation properties. Yet, the impact of guest presence inside a macrocycle prior to adsorption has not been studied. Here we show that the inclusion of trimethoxybenzyl-azaphosphatrane in the macrocycle cucurbit[8]uril (CB[8]) affords molecular Porous Host•Guest Crystals (PHGC-1) featured by radically new properties. Unactivated hydrated PHGC-1 adsorbed iodine spontaneously and selectively at room temperature and atmospheric pressure. The absence of (i) heat for material synthesis, (ii) moisture sensitivity and (iii) energy-intensive steps for pore activation are attractive attributes for decrease of energetic costs. 1H NMR and DOSY were instrumental to monitor the H2O/I2 exchange. Finally, PHGC-1 are non-centrosymmetric and I2 doped crystals showed markedly different Second Harmonic Generation (SHG) suggesting that iodine doping could be used to modulate the non-linear optical properties of porous organic crystals.
Collaborations :
iSm2, ICR, MADIREL, institut Fresnel, Spectropole, Université de Strasbourg
https://supra-mars.univ-amu.fr/
Financial support :
Aix-Marseille Université, CNRS, Institut AMUTech