Laboratoire de Chimie de Coordination UPR 8241


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Conférence Pr Emmanuel Cadot,
Institut Lavoisier de Versailles

Vendredi 3 décembre 2021 à 11h - Auditorium Fernand Gallais

"Chaotropic Effect as Motif Assembly in POM Chemistry"
Contact LCC : Dr Eric Manoury , eric.manoury chez lcc-toulouse.fr


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Clément Falaise, Mohamed Houas, Nathalie Leclerc &
Emmanuel Cadot*

Institut Lavoisier de Versailles UMR 8180, UVSQ,
Université Paris-Saclay, 78035 Versailles, France.
emmanuel.cadot chez uvsq.fr

Controlling aggregation processes in solution offers promising opportunities for tailoring and engineering properties of multi-component materials to some specific functions and applications. In context, supramolecular hybrid systems built on multicomponent organic-inorganic systems and polyoxometalates (POMs) demonstrated high ability to produce in aqueous solution, well-designed aggregates characterized in the solid state by single-crystal X-ray diffraction (see example in Fig.1) or in solution using multinuclear NMR methods (including DOSY, EXSY and COSY), ESI-mass and UV-vis spectroscopies, electrochemistry and ITC experiments.[1] Solution study demonstrates clearly that highly specific and cooperative pre-associations exist in solution for which binding constants and thermodynamic parameters have been determined, giving preliminary arguments about the chaotropic nature of the POMs.[1] Some examples will be reported showing that three- component well-ordered hybrid materials derived either as supramolecular hydrogel or crystalline solids can be produced through the straightforward non-covalent approach. Such fundamental phenomena open a wide scope for the design of hybrid materials, allowing :
i) the control of the polycondensation of metalate ions,[2,3]
ii) the design of redox-responsive host- guest systems,
iii) to construct highly ordered hybrid systems[4] and
iv) to self-assemble POMs with non-ionic surfactants into membrane-like organizations.

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Fig. 1 : Hierarchical supramolecular assembly based on Mo154 ring-shaped polyoxometalate, cyclodextrin and archetypical Dawson POM.





[1] M. A. Moussawi, N. Leclerc-Laronze, S. Floquet, P. A. Abramov, M. N. Sokolov, S. Cordier, E. Monflier, H. bricout, D. Landy, M. Haouas, J. Marrot, E. Cadot, J. Am. Chem. Soc. 2017, 139, 12793.

[2] Falaise, C. ; Moussawi, M. A. ; Floquet, S. ; Abramov, P. A. ; Sokolov, M. N. ; Haouas, M. ; Cadot, E. J. Am. Chem. Soc. 2018, 140 (36), 11198–11201.

[3] C. Falaise, S. Khlifi, P. Bauduin, P. Schmid, W. Shepard, A. A. Ivanov, M. N. Sokolov, M. A. Shestopalov, P. A. Abramov, S. Cordier, J. Marrot, M. Haouas,
E. Cadot, Angewandte Chemie International Edition 2021, 60, 14146–14153. [4 ] M. A. Moussawi, M. Haouas, S. Floquet, W. E. Shepard, P. A. Abramov, M.
N. Sokolov, V. P. Fedin, S. Cordier, A. Ponchel, E. Monflier, J. Marrot, and E. Cadot, J. Am. Chem. Soc. 2017, 139, 14376-14379.