Synthesis of a New Metal-ion Responsive Azacrown Coumarin Containing Photoluminescent Polypeptide to Investigate the Metal Ions Induced Supramolecular Assembly Behaviors and the Feasibility as the Formation of Mercury Nanoparticle Template / Synthesis and Exploration of Pyridine Containing Polypeptides in the Catalytic Application

• Main Authors: Chun-Hsiang Wang, 王俊翔
• Other Authors: Chao-Tsen Chen
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/69q76g

碩士 === 國立臺灣大學 === 化學研究所 === 107 === Forming supramolecular assemblies and controlling their behaviors via non-covalent interactions mimicking multi-functional materials have drawn much attention. Utilization of strong and directional interactions such as metal-ligand coordination can achieve spontaneous formation of selective, simple, and reversible supramolecular assemblies. However, it still remains a great challenge to monitor the underlying supramolecular assembly temporally. Herein, a new metal ion-responsive azacrown coumarin-conjugated photoluminescent polypeptide (ACCP) was designed and synthesized via in situ generated N-carboxyanhydride from the corresponding activated urethane monomer to exploit the metal ion-induced supramolecular assembly behaviors. After screening with various metal ions in either acetonitrile or chloroform, the results showed that ACCP˙Cu2+ exhibited blue emission in acetonitrile. However, ACCP dissolved in chloroform displayed strong fluorescence intensity enhancement only in the presence of either Hg2+ or Na+. In the combination of the absorption and the fluorescence profile, the morphologies of ACCP can be deduced. Notably, ACCP can also induce the formation of mercury nanoparticle. The morphologies of the mercury nanoparticle was 10 nm solid nanosphere stabilized by ACCP which was confirmed by transmission electron microscope. ACCP induced mercury nanoparticle was further used as the catalyst in Beckmann rearrangement. The preliminary results show that ACCP induced mercury nanoparticle was unable to catalyze the reaction due to the fact that the mercury nanoparticle was encapsulated compactly in the interior of the polymersome, rendering the mercury nanoparticles not accessible to the substrates. Further optimization of the reaction condition is required. Inspired by the ACCP induced mercury nanoparticle, polypeptide containing the pyridine ligands were designed and synthesized. Taking the advantage of the chirality in the polypeptide and the immobilization of the palladium via pyridine ligands, it is hoped to achieve good stereoselectivity in the synthesis of unnatural amino acid and the recover the palldium. A new synthetic strategy was developed to synthesize polymerizable monomer with the pyridine ligand to mitigate the contamination of the palladium needed to used in the original strategy. Based on this strategy, PPy-Lys, MPy-Lys, OPy-Lys, and Y-Lys were successfully synthesized, PPy-PLL and MPy-PLL were obtained in good yield with molecular weight around 8 kDa. PPy-PLL was further used as a ligand to C-H activation. The results revealed that PPy-PLL was unable to improve either yield or enantioselectivity. New ligands are required to achieve the C-H activation and high enantioselectivity.