Résumé
Ionic species, such as polyoxometalates (POMs) or (metal-) boron clusters, are at the frontier between ions and (charged-)colloids due to their nm size.1a The large size and low charge density of these nano-ions, compared to classical ions, are responsible for a peculiar behavior called “super-chaotropy”.1b, 2a, 3 This property refers to the surprisingly strong propensity of nano-ions to adsorb to neutral polar interfaces and to interact with macrocycles. This property results from the dehydration of (i) the weakly hydrated nano-ions, which has a reduced enthalpic cost compared to smaller ions, and of (ii) the surface (or macrocycle). A simple experimental procedure, based on cloud point measurement, was proposed lately for evaluating and classifying nano-ions according to their super-chaotropy.1b The super-chaotropic behavior of nano-ions opens opportunities in separation science,2a catalysis, and for the design of nanostructured hybrid materials.2bReferences[1]a) A. Malinenko, A. Jonchère, S. Maynadié, L. Girard, O. Diat, P. Bauduin P. Langmuir 34(5) 2018, 2026 b) T. Buchecker, P. Schmid, S. Renaudineau, O. Diat, A. Proust, A. Pfitzner, P. Bauduin, Chem. Commun. 54(15) 2018, 1833.[2] a) B. Naskar, O. Diat, V. Rataj, P. Bauduin, J. Phys. Chem. C 119 (36) 2015, 20985. b) T. Buchecker, X. LeGoff, B. Naskar, A. Pfitzner, O. Diat, P. Bauduin, Chem. - A Eur. J. 23 2017, 8434. c) T. Buchecker, P. Schmid, I. Grillo, S. Prévost, M. Drechsler, O. Diat, A. Pfitzner, P. Bauduin, J. Am. Chem. Soc. 2019 10.1021/jacs.8b12181[3] a) K. Assaf, M. Ural, F. Pan, T. Georgiev, S. Simova, K. Rissanen, D. Gabel, W. Nau, Angew. Chem. Int. Ed. 54(23) 2015, 6852 b) Assaf, K. I.; Nau, W. M., Angew. Chem. Int. Ed. 57 (43) 2018, 13968.