Self-assembly of multi-chromophoric nanostructured materials
Nanostructured organic chromophores materials find great application in the fields of photosynthetic systems and light harvesting antennae, synthetic ion channels, photovoltaic solar cells, organic semiconductors, and new supramolecular structures in material science, due to their intrinsic photophysical, photochemical, and electronic properties. This dissertation discusses two aspects of nanostructured organic chromophores materials based on supramolecular chemistry. In the first part, multilayer chromophores thin film with controlled molecular architecture and composition was constructed via layer-by-layer assembly thin film deposition techniques. In chapter 2, we report a straightforward layer-by-layer supramolecular deposition strategy to prepare numerous layers of functionalized perylene diimide (PDI) chromophores built upon a covalent scaffolding multivalent porphyrin monolayer. Our thin film formation strategy employs water as the immersion solvent and exploits the β-cyclodextrin-adamantane host-guest couple in addition to PDI based aromatic stacking. Within the resultant film the porphyrin scaffold is oriented close to parallel to the glass substrate whilst the PDI chromophores are aligned closer to the surface normal. Based on this strategy, we also demonstrate fabrication of photoresponsive multilayer porphyrin thin film with enhanced fluorescence intensity and singlet oxygen generation capabilities upon light irradiation. In particular, porphyrin functionalized with cyclodextrins and porphyrin bearing polyethylene glycol-adamantane groups have been well organized onto glass substrate forming multilayer thin films through self-assembly process based on adamantane and cyclodextrin host-guest supramolecular interaction. In the second parts, water compatible porphyrin containing nanoparticles with enhanced photo-physical properties based on cucurbituril host-guest supramolecular chemistry were synthesized and well characterized (chapter 3).