FRET-based mesoporous organosilica nanoplatforms for and anticancer two-photon photodynamic therapy.

We report the synthesis of multifunctional periodic mesoporous organosilica nanoparticles (PMO NPs) with substantial two-photon absorption properties and targeting capability for two-photon excitation fluorescence (TPEF) and photodynamic therapy (TPE-PDT). Prepared using an adapted sol-gel synthesis, the nanoplatforms integrated two silylated chromophores in their three-dimensional matrix to maximize non-radiative Förster resonance energy transfer from a high two-photon absorption fluorophore donor to a porphyrin derivative acceptor, leading to an enhanced generation of reactive oxygen species. Combinations of biodegradable and non-biodegradable bis(triethoxysilyl)alkoxysilanes were employed for the synthesis of the NPs, and the corresponding photophysical studies revealed high efficiency levels of FRET.

Emissive supramolecular ionic crystals combining a red-NIR phosphorescent [ReSeCN] cluster anion and a blue fluorescent tetraphenylethene counter-cation.

A blue fluorescent tetraphenylethylene-based dication and a red-NIR phosphorescent rhenium octahedral cluster tetra-anion are associated electrostatically to generate a supramolecular ionic framework which crystallizes in the 1̄ centric space group. The emission properties of the hybrids are studied in the crystalline state and in solution revealing a resonant energy transfer and a high sensitivity toward oxygen.

Luminescent Supramolecular Ionic Frameworks based on Organic Fluorescent Polycations and Polyanionic Phosphorescent Metal Clusters.

Emissive ionic supramolecular frameworks are designed by associating tetraphenylethylene-based tetra-cationic units and di-anionic molybdenum or tetra-anionic rhenium octahedral clusters. Obtained structures were characterized by single-crystal X-ray diffraction. The emission properties of the hybrids were investigated as dry powders or in various solvents by one photon and two photon absorption leading to a O concentration dependent luminescence color for the Mo based hybrid.

Photoinduced electron transfer between a noble-metal-free [MoICl] cluster and polyoxometalates.

Evidence for photoinduced intermolecular electron transfer from the excited state of the [MoICl] electron-rich cluster to polyoxometalates (POMs) is reported. We demonstrate that the global charge density of POMs affects the efficiency of electron transfer. This work paves the way for the rational design of photocatalytic systems using cluster-based complexes as robust noble-metal-free photosensitizers.

Game of Crowns: Na Is Coming! Red NIR-Emissive Hybrid Liquid Crystals Containing Discotic Crown Ethers and NaMoXCl (X = Cl or Br).

Molecular or supramolecular materials that can self-organize into columns such as discotic liquid crystals are of interest for several applications in the field of optoelectronics. We show in this work that red near-infrared (NIR)-emissive metal cluster compounds of general formula NaMoXCl (X = Cl or Br) can be readily complexed with discotic liquid crystals containing a crown ether. Three cavity sizes have been tested with crown ethers bearing 4, 5, or 6 oxygen atoms.