Photoelectron circular dichroism of molecular and cluster anions

• Project/Area Number: 17K19098
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Research Field: Physical chemistry, Functional solid state chemistry, and related fields
• Research Institution: National Institutes for Quantum and Radiological Science and Technology (2018-2019); The University of Tokyo (2017)
• Principal Investigator: Nakanishi Ryuzo 国立研究開発法人量子科学技術研究開発機構, 高崎量子応用研究所 東海量子ビーム応用研究センター, 主任研究員(定常) (70447324)
• Project Period (FY): 2017-06-30 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥6,240,000 (Direct Cost: ¥4,800,000、Indirect Cost: ¥1,440,000); Fiscal Year 2019: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2018: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2017: ¥3,380,000 (Direct Cost: ¥2,600,000、Indirect Cost: ¥780,000)
• Keywords: 負イオン光電子分光 / 円二色性 / 光電子イメージング / 分子クラスター / 光電子分光 / キラリティ

Outline of Final Research Achievements

We have developed a new instrument for imaging photoelectron circular dichroism (PECD) of gas-phase anions. The PECD capability was integrated to the velocity-map photoelectron imaging apparatus. Using circularly polarized laser light, we observed chiral effects in the angular distribution of photoelectron emission from chiral anions; photodetachment from pure enantiomers of the chiral alkoxide anions show the forward-backward scattering asymmetry of photoelectrons along the light propagation direction. The asymmetry reverses with the exchange of the enantiomer or of the laser light helicity. This study has demonstrated that negative-ion PECD provides unique opportunity to study chirality of isolated molecular and cluster anions.

Academic Significance and Societal Importance of the Research Achievements

キラリティが関与する反応過程の解明や制御には，その物質のキラリティの識別が不可欠である。本研究では，光電子円二色性イメージングによる気相負イオン種のキラリティ識別を行い，超微量・高感度キラル計測の新手法としての有用性を明らかにした。この成果は今後，準安定的なイオン種や分子集合体といった過渡的に存在するイオン種のキラリティ検出を通じて，キラリティの関与するダイナミクスにおける分子間相互作用の効果の解明に繋がると期待される。

Research Products

• [Journal Article] Ab initio MRCI study on potential energy curves for a single Cl loss from the palladium tetrachloride anion PdCl42? (2020)
  • Author(s): Kurosaki Yuzuru、Nakanishi Ryuzo、Saeki Morihisa、Ohba Hironori
  • Journal Title: Chemical Physics Letters Volume: 746 Pages: 137288-137288
  • DOI: 10.1016/j.cplett.2020.137288
  • Peer Reviewed
• [Journal Article] Photoinduced gold recovery mediated by isopolymolybdate in strongly acidic HCl/NaCl solutions (2019)
  • Author(s): Nakanishi Ryuzo、Saeki Morihisa、Taguchi Tomitsugu、Ohba Hironori
  • Journal Title: Journal of Photochemistry and Photobiology A: Chemistry Volume: 383 Pages: 111994-111994
  • DOI: 10.1016/j.jphotochem.2019.111994
  • Peer Reviewed
• [Journal Article] Photoelectron Spectroscopy of Molecular Anion of Alq3: An Estimation of Reorganization Energy for Electron Transport in the Bulk (2018)
  • Author(s): Toshiaki Yanase, Ryuzo Nakanishi, Satoru Muramatsu, Kiichirou Koyasu, Hiroyuki Yoshida, Takashi Nagata, and Tatsuya Tsukuda
  • Journal Title: ACS OMEGA Volume: 3 Issue: 11 Pages: 15200-15204
  • DOI: 10.1021/acsomega.8b02206
  • NAID: 120006892723
  • Peer Reviewed / Open Access