Theoretical exploration of sensitive chemical probe methods utilizing collective electron motions

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K05394
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Physical chemistry
• Research Institution: The Open University of Japan
• Principal Investigator: YASUIKE Tomokazu 放送大学, 教養学部, 准教授 (10419856)
• Co-Investigator(Renkei-kenkyūsha): WATANABE Kazuya 京都大学, 大学院理学研究科, 准教授 (30300718) ; MIYAJIMA Ken 東京大学, 大学院総合文化研究科, 助教 (20365456)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 電子状態理論 / クラスター / プラズモン / 共鳴ラマン散乱 / 表面光化学

Outline of Final Research Achievements

The plasmon-enhanced Raman spectra for composite systems consisting of plasmonic clusters and analyte molecules were calculated in a quantum mechanical manner and their enhancement factors (EFs) were estimated. A theoretical analysis revealed that the EF becomes large for systems having dipole-type difference transition densities with regard to displacements in normal modes. This picture for the EF leads to a novel TERS imaging. It has been found that the utilization of tips modificated with atoms and clusters enable us to obtain vibrational-mode dependent images, which contains information about molecular orientations. Moreover, the above mechanism for the EF predicts large enhancements also for transition metal clusters that are usually not regarded as effective sensitizer for Raman scattering. This properties open up the possibility of in-situ vibrational spectral analysis of chemical reactions on transition metal clusters, which are recent hot topics in catalytic chemistry.

Free Research Field

理論分子科学