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

Abstract

International audienceAt 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 [(Re6Yi8)Ya6] cluster units (Y = chalcogen and/or halogen) can be functionalized via solution chemistry techniques or organic melts to form [(Re6Yi8)La6] (L = CN, OH, various organic ligands...). This work reports advances in the synthesis of [(Re6Yi8)Ya6] and [(Re6Yi8)La6] 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

Molecular Oxygen Modulated Luminescence of an Octahedro‐hexamolybdenum Iodide Cluster having Six Apical Thiocyanate Ligands

“…The combination of two interfering functionalities, namely the luminescence and singlet oxygen production, make these materials unique and raises potential for applications in molecular oxygen sensing, singlet oxygen generation, and so on. Similar properties are evident not only for halide compounds such as [Mo 6 X 8 ] and [W 6 X 8 ], but also in [Re 6 Q 8 ] cluster cores (Q = S, Se, Te) 19,20. However, studies on [W 6 I 8 ] compounds are systematically missing because during the past, because there has been no useful tungsten iodide source available.…”

Time-gated luminescence bioimaging with new luminescent nanocolloids based on [Mo6I8(C2F5COO)6]2−metal atom clusters

“…Owing to the ionic nature of the interaction between the cluster units and the countercations (K + , Cs + , tetrabutylammonium…), the solid state powder can be dispersed at nanosized level in solution. 30 Even after high dispersion in organic or inorganic matrix, Mo6 or Re6 metal atom clusters exhibit a characteristic broad emission band in the red and NIR (550-900 nm), 30,34,40 which is particularly interesting for biotechnology applications as it corresponds to a low human tissues absorption at these wavelengths. Moreover, some of these MC could generate singlet oxygen under irradiation, which is of particular interest for photodynamic therapy (PDT) applications.…”

Supramolecular Frameworks Built up from Red‐Phosphor­escent trans‐Re6 Cluster Building Blocks: One Pot Synthesis, Crystal Structures, and DFT Investigations

“…[1][2][3][4] Beyond carrying specific luminescence, sensitization, catalytic and photo-catalytic properties, they could be involved in the material structuration by self-assembling of organic cationic frameworks [5] in charge transfer salts thanks to their ability to form hydrogen bonding. Indeed, many molecular assemblies and nanomaterials built up from M 6 clusters carriers of original chemical and physical properties [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] or as structuring moieties have been reported these last years. [26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43] M 6 clusters in medium oxidation state are stabilized by inorganic face-capping and terminal inorganic or organic ligands to form [{M 6 Q ], interstitial L ligands and water molecules.…”