Theoretical study for the observation of transition state of chemical reaction

2019 Fiscal Year Final Research Report

• Project/Area Number: 17KT0093
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 特設分野
• Research Field: Transition State Control
• Research Institution: Saitama University
• Principal Investigator: TAKAYANAGI Toshiyuki 埼玉大学, 理工学研究科, 教授 (90354894)
• Project Period (FY): 2017-07-18 – 2020-03-31
• Keywords: 遷移状態 / 反応動力学 / 量子波束法 / 非断熱遷移 / ポテンシャルエネルギー曲面 / 量子化学 / 分子衝突

Outline of Final Research Achievements

The concept of “transition state” has been important to intuitively grasp the essence of the kinetics, mechanisms and dynamics of chemical reactions. It is generally difficult to directly observe the transition state due to its short lifetime. However, there have been a few experimental techniques that can obtain the information on the transition state region of the potential energy surface with spectroscopic methods. Such methods are called “transition state spectroscopy”and one of the successful methods is to employ a molecular anion. However, it is frequently difficult to interpret the measured spectrum only from the experimental information since the transition state structure is very different from that of the stable molecule and has a finite lifetime. In this project, we have been performing quantum wave packet dynamics calculations combined with ab initio electronic structure calculations to understand the measured transition state spectra at a quantitative level.

Free Research Field

理論化学

Academic Significance and Societal Importance of the Research Achievements

化学反応の本質は、瞬間的な分子結合の解離や生成である。化学反応がどのような分子構造を変化を経て進行しているかを理解することは重要である。本研究課題では、理論と実験の共同作業によって、化学反応の鍵である「遷移状態構造」の情報を直接得ることができることを示すことができた。