Studies On Self-assembly And Functionalization Of Metal-organic Polyhedra

Biochemical reactions, which are necessary for all life processin living systems, undergo a series of recognition and catalytic process. Metal organic polyhedra (MOPs) are a kind of highly ordered entity which are self-assembled by the metal ions with a specific coordination geometry and the ligands. MOPs have unique structure and the cavity of the particular size. By introducing the catalytic and recognition sites in their cavity, MOPs could recognize guest molecules through supramolecular interaction and catalyze reactions mimicking enzymes.1The recognition of biological molecules based on metal-organic polyhedraThe octa-nuclear bicoronal triangular prism Ce-L1could be self-assembled by the four-arms ligands of thirty-six amide group and Ce3+. It could high selectively recognize lactose among related natural mono-and disaccharides solution through multiple hydrogen bonding sites of twelve amide bond groups and size selection. Tetrahedral complexes of Zn-L2, Co-L2were designed and synthesized to recognize ATP. The tetrahedral complexes worked as fluorescence sensors to selectively recognize ATP among ribonucleotide molecules based on fluorescence characteristics of triphenyl amine groups.2Studies on organic reactions catalyzed by metal-organic polyhedraThe Cerium-based warped tetrahedral structures Ce-L3and Ce-L4self-assembled from two ligands and Ce3+were designed and synthesized. They could recognize4-nitrobenzaldehyde and worked as molecular flasks to catalyze cyanosilylation reactions of aldehyde molecules. The tetrahedron Ce-L5containing amide groups and large conjugate planes could recognize2-(anthracen-9-yl)acetaldehyde accompany with signal output of the fluorescent and NMR. It worked as a molecular flask to catalyze photodimerization reactions of9-anthracene acetaldehyde through π-π interaction and get [4,4] cyclo-dimerization product. The cyanosilylation reactions were tracked by NMR which showed pseudo-zeroth-order characteristics at high concentration, and the reaction process could be inhibited by a inhibitor. It is suggested that the catalytic process worked as enzyme kinetics.3Studies on supramolecular photochemistryThe supramolecular systems containing polypyridyl ruthenium complexes and polyoxometalates have stable electrochemical and optoelectronic signals under photoreation, and the assembled supramolecular systems are morestable and stronger than a single system to achieve supramolecular systems for promotion of electrochemical and optoelectronic signals. In the hydrogen production system where fluorescein worked as a photosensitizer and triethylamine as an electron sacrificial agent, tetrahedral complexes Co-L7exhibited host-guest supramolecular interaction with photosensitizer fluorescein. The evolution of hydrogen production is significantly higher than the reaction system with corresponding cobalt-based mononuclear complexes Co-L8. It is suggested that the supramolecular interactions play an important role in light-driven the hydrogen production system and realized the promoting of hydrogen production through supramolecular interaction.