Dissipative Supramolecular Reactor

2021 Fiscal Year Annual Research Report

• Project/Area Number: 21F21037
• Allocation Type: Single-year Grants
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: 相田 卓三 国立研究開発法人理化学研究所, 創発物性科学研究センター, グループディレクター (00167769)
• Co-Investigator(Kenkyū-buntansha): GOSWAMI ABIR 国立研究開発法人理化学研究所, 創発物性科学研究センター, 外国人特別研究員
• Project Period (FY): 2021-11-18 – 2024-03-31
• Keywords: Supramolecular polymer / Perfluorinated monomer

Outline of Annual Research Achievements

I have successfully synthesized the different type of substituted pyridine and terpyridines building blocks and characterized with different spectroscopic techniques. Optimize the reaction conditions for synthesizing our desired monomer ligand with flexible hydrophobic tail and polar aza-crown ether unit. After a discussion with the host PI, I have realized another approach to achieve our goal with the help of fluorine chemistry. I have successfully synthesized a new perfluorinated heterocyclic crown ether. The crown ether shown nice assembly behavior in water to furnish a 1D nanofibers. The fibers were characterized with scanning electron microscope and MALDI-TOF. I have successfully optimized the condition to tune the length of the fibers by changing the concentration and temperature.

Current Status of Research Progress

2: Research has progressed on the whole more than it was originally planned.

Reason

After synthesizing the final monomer ligand with flexible hydrophobic tail and polar aza-crown ether unit, I will optimize (choice of metal ions, solvent, critical concentration, temperature, pH) the formation of mechanically robust 2D bilayer-nanotube. I have developed a new strategy to functionalize the PCH with different reactive groups (-NH2, -OH, -maleimide) for further studies. Although the nanofibers are quite large enough to see with optical microscopy the actual arrangement of the PHC in the fiber is not clear, whether it is rod like or tube-like structures. We are expecting to solve this problem by characterization through electron microscopy, AFM and 2D WAXD. To check our hypothesis and further biological studies, I must attach a water-soluble hydrophilic dye molecule with PHC.

Strategy for Future Research Activity

After synthesizing the final terpyridine/pyridine-based monomer ligand with flexible hydrophobic tail and polar aza-crown ether unit, I will characterize through nuclear magnetic resonance and mass spectroscopy. Optimization (choice of metal ions, solvent, critical concentration, temperature, pH) of the formation of mechanically robust 2D bilayer-nanotube will be done. Finally, I would like to check the mechanical properties of such fibers. Also, the charge distribution of PHC suggest that it can break the water cluster barrier of cell membrane. We expect that perfluorinated-crownether can solve the problem of blood brain barrier by acting as a small drug carrier. I must attach a water-soluble hydrophilic dye molecule with PHC for further studies.