Advances in the Engineering of Near Infrared Emitting Liquid Crystals and Copolymers, Extended Porous Frameworks, Theranostic Tools and Molecular Junctions Using Tailored Re6 Cluster Building Blocks

At the occasion of the fiftieth birthday of the introduction of the term ‘metal atom cluster’ by F. A. Cotton in inorganic chemistry, it is the good time to make a review on the advances in the engineering of molecular assemblies and nanomaterials based on octahedral Re6 metal atom clusters. The latter exhibit unique intrinsic structural and physicochemical properties (orthogonal disposition of metallic sites that can be selectively functionalized, photoluminescence, redox, generation of singlet oxygen) that make them relevant building blocks for the structuration at the nanometric scale and functionalization of hybrid organic-inorganic materials and supramolecular frameworks. After synthesis by solid state chemistry techniques at high temperature, inorganic precursors built up on face-capped [(Re6Y8)Y6] cluster units (Y = chalcogen and/or halogen) can be functionalized via solution chemistry techniques or organic melts to form [(Re6Y8)L6] (L = CN, OH, various organic ligands...). This work reports advances in the synthesis of [(Re6Y8)Y6] and [(Re6Y8)L6] cluster units as well as on their use in the elaboration of supramolecular frameworks, nanoparticles, hybrid nanomaterials (co-polymers and liquid crystals) and active molecular junctions.