Takeshi Iwasa

Graduate School of Science, Hokkaido University
Assistant professor
A02

Research AreasQuantum Chemistry, Molecular Physics
Participating Group (2020-2021)

Excited States and Emission Mechanisms of Molecular Crystals

Keywords
Molecular Crystal, Few-Body Systems, Quantum Chemistry Calculations, Intermolecular interactions
Co-Researcher
Co-Researcher: Tetsuya Taketsugu (Graduate School of Science, Hokkaido University, Professor)

Research Outline

Weak macroscopic stimulations can induce structural phase transitions for some molecular systems changing their luminescent properties. To understand the excited states and optical properties of these systems, one has to study the relaxation pathways for their excited states of a molecule or few-molecule under surroundings because the luminescence properties of a molecule depend on the crystal structure. In this study, we will develop a method that can study the relaxation pathway of these systems that includes explicit inter-molecular interactions in a condensed phase toward full understandings on the excited states and therefore the crystal structure-dependent luminescence properties.

Development of a method for emission mechanisms of molecular crystals
Participating Group (2018-2019)

Theoretical Study of Excited States and Emission Mechanisms of Molecular Crystals

Keywords
Molecular Crystal, Few-Body Systems, Quantum Chemistry Calculations, Excited States Molecular Dynamics, Non-adiabatic transitions
Co-Researcher
Co-Researcher: Tetsuya Taketsugu (Graduate School of Science, Hokkaido University, Professor)

Research Outline

Weak macroscopic stimulations can induce structural phase transitions for some molecular systems changing their luminescent properties. To understand the excited states and optical properties of these systems, one has to study the relaxation pathways for their excited states of a molecule or few-molecule under surroundings because the luminescence properties of a molecule depend on the crystal structure. In this study, we will develop a method that can study the relaxation pathway of these systems that includes explicit inter-molecular interactions in a condensed phase toward full understandings on the excited states and therefore the crystal structure-dependent luminescence properties.

Development of a methods for luminescent properties of molecular crystals

Publications

Academic papers/reviewed

A02-11

  1. "Photo‐Induced Pyramidal Inversion Behavior of Phosphines Involved with the Aggregation‐Induced Emission (AIE) Behavior" T. Machida, T. Iwasa, T. Taketsugu, K. Sada, K. Kokado, Chemistry – A European Journal, 2020, in press.
  2. "Spiral Eu(III) Coordination Polymers with Circularly Polarized Luminescence" Y. Hasegawa, Y. Miura, Y. Kitagawa, S. Wada, T. Nakanishi, K. Fushimi, T. Seki, H. Ito, T. Iwasa, T. Taketsugu, M. Gon, K. Tanaka, Y. Chujo, S. Hattori, M. Karasawa, K. Ishii, Chem. Comm., 2018, 54, 10695-10697.
  3. "First Principles Calculations Toward Understanding SERS of 2,2′-Bipyridyl Adsorbed on Au, Ag, and Au–Ag Nanoalloy" M. Takenaka, Y. Hashimoto, T. Iwasa, T. Taketsugu, G. Seniutinas, A. Balčytis, S. Juodkazis, Y. Nishijima, J. Comput. Chem., 2019, 40, 925-932.
  4. "Combined Automated Reaction Pathway Searches and Sparse Modeling Analysis for Catalytic Properties of Lowest Energy Twins of Cu13" T. Iwasa, T. Sato, M. Takagi, M. Gao, A. Lyalin, M. Kobayashi, K. Shimizu, S. Maeda, T. Taketsugu, J. Phys. Chem. A, 2019, 123, 210-217.
  5. "Photoluminescence Properties of [Core+exo]-Type Au6 Clusters: Insights into the Effect of Ligand Environments on the Excitation Dynamics" Y. Shichibu, M. Zhang, T. Iwasa, Y. Ono, T. Taketsugu, S. Omagari, T. Nakanishi, Y. Hasegawa, K. Konishi, J. Phys. Chem. C, 2019, 123, 6934-6939.
  6. "Low-lying Excited States of hqxcH and Zn-hqxc Complex: Toward Understanding Intramolecular Proton Transfer Emission" M. Ebina, Y. Kondo, T. Iwasa, T. Taketsugu, Inorg. Chem., 2019, 58, 4686-4698.

Related Website(s)
Contact
tiwasa[at]sci.hokudai.ac.jp