Final Report Summary - PHOXNA (Photo-Induced Processes in oxalate network based nano-objects)
Interaction between light and matter is of fundamental importance in physical, chemical and biological sciences, because of a variety of applications, for instance in optical information technology devices, in lasers and lighting, and in solar-energy harvesting. Coordination chemistry provides a convenient tool to prepare solids with tailored optical properties. However, the actual use of such materials in devices requires processing of the compounds into well-defined and often size-reduced particles. This project aims at the preparation of nano-objects, starting from oxalate-based networks, well known for their optical and magnetic properties. For example, [M(bpy)3][NaCr(ox)3] 3D networks are known to present a photo-induced energy migration process within the CrIII cations over large distances (up to 100 nm when M = RuII) or an unusual spin crossover behaviour when M = CoII.
In a first step, the adaptation of nanochemistry methods (reverse-micelles technique) to this family of compounds, in order to obtain size-controlled particles has been performed. With [Ru(bpy)3][NaCr(ox)3] nanoparticles, the influence of size reduction on the energy migration process has been investigated. A size-dependent directional energy migration towards the nanocrystal’s surface has been evidenced. The preparation of functionalized nano-objects able to harvest the energy migrating at the surface, either by grafting complexes or by epitaxial growth of a different oxalate network shell on the surface, have been realized. The synthesis of core-shell nano-objects has been achieved. However, the core-to-shell energy transfer is not efficient in such systems. Therefore, the grafting of lanthanide complexes at the nanocrystal surface has been envisaged. Preliminary results suggest that this approach is a promising way to prepare functionnalized nano-objects.
In a first step, the adaptation of nanochemistry methods (reverse-micelles technique) to this family of compounds, in order to obtain size-controlled particles has been performed. With [Ru(bpy)3][NaCr(ox)3] nanoparticles, the influence of size reduction on the energy migration process has been investigated. A size-dependent directional energy migration towards the nanocrystal’s surface has been evidenced. The preparation of functionalized nano-objects able to harvest the energy migrating at the surface, either by grafting complexes or by epitaxial growth of a different oxalate network shell on the surface, have been realized. The synthesis of core-shell nano-objects has been achieved. However, the core-to-shell energy transfer is not efficient in such systems. Therefore, the grafting of lanthanide complexes at the nanocrystal surface has been envisaged. Preliminary results suggest that this approach is a promising way to prepare functionnalized nano-objects.