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L’ adsorption de molécules d’iode (I2) présente un intérêt crucial lorsque des isotopes radioactifs impliqués dans le cancer de la thyroïde sont relargués dans les centrales nucléaires ou après des accidents nucléaires. Le nouveau matériau découvert, composé de cristaux moléculaires formés par l’empilement de complexes Hôte-Invité, possède des canaux très affins pour les molécules d’iode, bien que ces canaux soient remplis d’eau. Cette propriété est remarquable pour des utilisations en conditions réelles, tout comme les économies d’énergie liées à l’obtention et l’activation de cette nouvelle catégorie de matériaux.
Yang Xue, Li Chunyang, Giorgi Michel, Siri Didier, Bugaut Xavier, Chatelet Bastien, Gigmes Didier, Yemloul Mehdi, Hornebecq Virginie, Kermagoret Anthony, Brasselet Sophie, Martinez Alexandre, Bardelang David
Angewandte Chemie International Edition, 61 e202214039 (2022)
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) with 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 decreasing the energy costs. 1H NMR and DOSY were instrumental for monitoring the H2O/I2 exchange. PHGC-1 crystals are non-centrosymmetric and I2-doped crystals showed markedly different second harmonic generation (SHG), which suggests that iodine doping could be used to modulate the non-linear optical properties of porous organic crystals.
Référence :
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.
Résumé publié dans le journal :
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/
Financements :
Aix-Marseille Université, CNRS, Institut AMUTech