Molecular Magnetic Field-Sensing Systems and Their Applications

Abstract: 

Interaction between molecules and magnetic fields is an intriguing topic in fundamental science. Most known magnetic field effects in molecular systems can be explained by the radical ion pair (RIP) mechanism, where the intersystem crossing (ISC) rate is modulated by an external magnetic field. In this talk, I will present recent studies from our lab on magnetic field-sensing molecular systems, employing various methods including spectroscopy, electrochemistry, microscopy, quantum mechanical simulations, and so on. I will focus particularly on exciplex-forming molecular systems, such as pyrene-(CH₂)₁₂-O-(CH₂)₂-N,N-dimethylaniline (Py-12-O-2-DMA) and peptoid-conjugated Py-DMA systems [1,2]. These systems operate in three stages: exciplex formation, magnetic field-sensing, and exciplex emission. I will discuss characteristics of each stage in detail, emphasizing experimental evidence that highlights the balance between exciplex and RIP as a critical factor for magnetic field-sensing in molecular systems. Potential applications of these systems in a magnetic field imaging agent, singlet oxygen O₂(¹Δ_g) generation photosensitizer, and a molecular spin qubit will be introduced[3]. Additionally, I will discuss the photodegradation mechanism for Py-12-O-2-DMA[4]. 

References

“Peptoid-Conjugated Magnetic Field-Sensitive Exciplex System at High and Low Solvent Polarities”, D. Kim, Y. J. Lee, D. -H. Ahn, J. -W. Song, J. Seo and H. Lee J. Phys. Chem. Lett. 11 4668 (2020).

“Peptoid helix displaying flavone and porphyrin: Synthesis and intramolecular energy transfer”, W. Yang, J. Jo, H. Oh, H. Lee, W. Chung and J. Seo J. Org. Chem. (2019)

“Quantitative imaging of magnetic field distribution using a pyrene-based magnetosensing exciplex fluorophore”, D. Kim, M. Jung, H. Kim, W. Chung and H. Lee Photochem. Photobiol. Sci. 18 2688 (2019).

“Primary Photodegradation Pathways of an Exciplex-Forming A-D Molecular System”, Y. Ki, J. Kim, Y. Son, S. Park, W. -j. Chung, T. -Y. Kim, and H. Lee Mater. Adv. 5 8254 (2024).

20241121_대학원 세미나_이호재 교수.pdf