Selective chemical bond breaking induced by core-excitations: Approach by measurements of ultrafast charge transfer

2014 Fiscal Year Final Research Report

• Project/Area Number: 23550017
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Physical chemistry
• Research Institution: Hiroshima University
• Principal Investigator: WADA Shin-ichi 広島大学, 理学(系)研究科(研究院), 助教 (60304391)
• Project Period (FY): 2011-04-28 – 2015-03-31
• Keywords: 内殻励起反応 / サイト選択的結合切断 / 共鳴オージェ電子分光 / Core-hole clock法 / 自己組織化単分子膜（SAM）

Outline of Final Research Achievements

Site-selective chemical bond breaking characteristically induced by resonant core-excitations can be observed on surface molecules. It is considered that charge diffusion from reaction center to substrate has an important role to bring about such selectivity. In order to verify the above correlation, measurements of ion desorption and resonant Auger decay induced by core-excitations were performed for methyl-ester terminated self-assembled monolayers (SAMs) composed of conductive aromatic chains.
From time-of-flight measurements of photodesorbing ions, reaction mechanism was evaluated depending on site-selectivity. On the other hand, resonant Auger spectra below ionization threshold were analyzed based on core-hole clock method to derive ultrafast charge transfer rate. It was found that site-selectivity of ion desorption and charge transfer rate correlatively depend on difference of molecular chains: insulating aliphatic chain or conductive aromatic one, and chain length.

Free Research Field

物理化学