Df Metal Complexes Preparation Of The Particles Of Magneto-optical Properties And Application In Cell Imaging In The Study

Metal-Organic Frameworks (MOFs) have attracted growing interest in chemistry and materials science due to their unique and highly tailorable properties, which may offer new applications in heterogenerous catalysis, gas storage, biosensing and drug delivery. On the one hand, d-f complexes have strong visible absorption and phosphorescence based on metal-to-ligand charge-transfer transition (MLCT) process. On the other hand, Gd (â…¢) ions with seven unpaired electrons provide both high magnetic moment and long electronic relaxation times, enhancing the contrast of proton magnetic resonance signals by increasing the relaxation rates of the protons in water molecules interacting with the metal centre. Therefore, the unique property of d-f coordination polymer nanoparticles makes it most suitable for bifunctional probes for phosphorescence and magnetic resonance imaging. In the present thesis, we developed the general method to prepare magnetophosphorescent d-f coordination polymer nanoparticles performed by phosphorescent carboxyl-functionalized Ir(â…¢) complexes (ppy)₂Ir(H₂dcppy)PF6 as building blocks interconnected by magnetic Gd (â…¢) ions, providing a promising candidate for phosphorescence and magnetic resonance imaging. The details are shown as follows:Firstly, an iridium complex with two carboxylic acids was synthesized. Solid nanoparticles, hollow nanoparticles and nanowires were prepared with different reaction time and different additives such as NH₃•H₂O, NEt₃ and N(CH₂CH₂NH₂)₃. These nanoparticles shoned strong organge phosphorescence and moderate longitudinal relaxivity (r1).Secondly, to be successfully used as a bioprobe in living cells, it is indispensable to possess good water solubility. We adopted PVP to modify their surface to obtain water soluble nanoparticles by strong interaction between Lewis acid sites in nanoparticles and base site in PVP. With the MTT assay, they have little cytotoxicity. As confirmed by experiments in living cells, nanoparticles were unptaken into the cytoplasm of HeLa cells exclusively from confocal laser scanning microscopy (CLSM) and T1 MRI contrast agents. Therefore, d-f coordination polymer nanoparticles should be a novel nano-bioprobe for the multimodal imaging in living cells...