Multifunctional Supramolecular Gels with Strong Mechanical Properties Formed by Self-Assembly of Polyoxometalate-Based Coordination Polymers.

Metallogels built in a bottom-up approach by metal coordination and supramolecular interactions have important potential for the elaboration of smart materials. In this context, we present here the formation of supramolecular coordination polymers driven by the complexation of cobalt(II) or zinc(II) ions with polyoxometalate-based hybrids displaying two terpyridine ligands in a linear arrangement. Thanks to the electrostatic interactions between the polyoxometalate cores and metal nodes, the polymer chains self-assemble into fibers that physically cross-link to form gels above a critical concentration.

Single polyoxometalate-based nanoclusters characterized by infrared absorption nanospectroscopy.

Bottom-up engineering is a very attractive field. However, the periodic organization of molecules on a solid substrate is challenging, particularly in the selection of the appropriate characterization technique which is suitable for both large area and accurate analysis at the nanoscale. Here, this study demonstrates the unambiguous identification of complex molecular layers by infrared absorption microscopy at the nanometric scale.

Ready-to-be-addressed oxo-clusters: individualized, periodically organized and separated from the substrate.

Clusters and oxo-clusters are drawing attention for their amazing physical properties, especially at the scale of the single molecule. However, chemical methods to organize them individually on a surface are still lacking. In this study we show that it is possible to periodically organize individual polyoxometalates thanks to their ordering by a new supramolecular assembly.

Multi-Electron Visible Light Photoaccumulation on a Dipyridylamine Copper(II)-Polyoxometalate Conjugate Applied to Photocatalytic Generation of CF Radicals.

This article describes the synthesis and characterization of an organic-inorganic hybrid polyoxometalate functionalized by a short link with a tripodal N-based ligand and its copper complex. Upon visible light irradiation, the latter is able to store up to three reducing equivalents. The locus of the reduction is discussed based on physicochemical measurements and DFT calculations.

H Evolution at a Reduced Hybrid Polyoxometalate and Its Vanadium-Oxo Derivative Used as Molecular Models for Reducible Metal Oxides.

We herein report our investigations on the use of a tris-silanol-decorated polyoxotungstate, [SbWO(tBuSiOH)], as a molecular support model to describe the coordination of an isolated vanadium atom at metal oxides, focusing on the reactivity of the reduced derivatives in the presence of protons. Accumulation of electrons and protons at an active site is a main feature associated with heterogeneous catalysts able to conduct the (oxy)dehydrogenation of alkanes or alcohols. Our results indicate that two-electron reduced derivatives release H upon protonation, a reaction that probably takes place at the polyoxotungstic framework rather than at the vanadium center.