Cyclodextrin-Assisted Hierarchical Aggregation of Dawson-type Polyoxometalate in the Presence of {Re6Se8} Based Clusters

Anton Ivanov (1, 2) , Clement Falaise (1) , Alexandra A Shmakova (1, 2) , Nathalie Leclerc-Laronze (1) , Stéphane Cordier (3, 4) , Yann Molard (3, 4) , Yuri V Mironov (2) , Michael A. Shestopalov (2) , Pavel A. Abramov (5, 2) , Maxim N. Sokolov (2) , Mohamed Haouas (1) , Emmanuelle Cadot (1)

1 ILV - Institut Lavoisier de Versailles
2 NIC - Nikolaev Institute of Inorganic Chemistry [Novosibirsk]
3 ScanMAT - Synthèse Caractérisation Analyse de la Matière
4 ISCR - Institut des Sciences Chimiques de Rennes
5 SUSU - South Ural State University

The association of metallic clusters (CLUS) and polyoxometalates (POM) into hierarchical architectures is achieved using γ-cyclodextrin (γ-CD) as a supramolecular connector. The new self-assembled systems, so-called CLUSPOM, are formed from Dawson-type polyoxometalate [PWO] and electron-rich rhenium clusters. It is worth noting that a cluster-based cation [{ReSe}(HO)] on one hand and a cluster-based anion on the other hand [{ReSe}(CN)] can be associated with the anionic POM. In the absence of the supramolecular connector, a "CLUSPOM salt" was obtained from aqueous solution of the cationic cluster and the polyoxometalate. In this solid, the arrangement between the polymetallic building blocks is mainly governed by long-range Coulombic interactions. In the presence of γ-CD, the Dawson anion and the cationic cluster are assembled differently, forming a hierarchical supramolecular solid, K[{ReSe}(HO)]{[PWO]@2γ-CD}·42HO, where the organic macrocycle acts as a ditopic linker between the inorganic building blocks. In such an edifice, the short-range molecular recognition dominates the long-range Coulombic interactions leading to a specific three-dimensional organization. Interestingly, the assembling of anionic POM [PWO] with the anionic rhenium cluster [{ReSe}(CN)] is also achieved with γ-CD despite the repulsive forces between the nanosized anions. The resulting solid, K{[{ReSe}(CN)]@2γ-CD}[PWO]·33HO, is built from 12 inclusion complexes {[{ReSe}(CN)]@2γ-CD} linked by a POM unit interacting with the exterior wall of the organic macrocycle. Multinuclear NMR and small-angle X-ray scattering investigations support supramolecular preorganization in aqueous solution prior to crystallization.

Domaines: Chimie

Anton Ivanov, Clement Falaise, Alexandra A Shmakova, Nathalie Leclerc-Laronze, Stéphane Cordier, et al.. Cyclodextrin-Assisted Hierarchical Aggregation of Dawson-type Polyoxometalate in the Presence of {Re6Se8} Based Clusters. Inorganic Chemistry, 2020, 59 (16), pp.11396-11406. ⟨10.1021/acs.inorgchem.0c01160⟩. ⟨hal-02930227⟩