Graduate School of Frontier Biosciences, Osaka University

Japanese

Relaxation dynamics of [Re(CO)2(bpy){P(OEt)3}2](PF6) in TEOA solvent measured by time-resolved attenuated total reflection terahertz spectroscopy

Journal Sci Rep 9, 11772 (2019)
Authors Nguyen PN (1), Watanabe H (1, 2), Tamaki Y (3), Ishitani O (3), Kimura SI (1, 2)
  1. Department of Physics, Graduate School of Science, Osaka University, Toyonaka, Osaka, 560-0043, Japan
  2. Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, 565-0871, Japan
  3. Department of Chemistry, Tokyo Institute of Technology, Meguro-ku, Tokyo, 152-8551, Japan
Title Relaxation dynamics of [Re(CO)2(bpy){P(OEt)3}2](PF6) in TEOA solvent measured by time-resolved attenuated total reflection terahertz spectroscopy
PubMed 31409913
Laboratory Photophysics Laboratory 〈Prof. Kimura〉
Abstract To reveal highly efficient photocatalytic properties of an artificial photosynthesis material [Re(CO)2(bpy){P(OEt)3}2](PF6), we have directly observed the photo-induced relaxation dynamics and reductive quenching process of the photo-excited state on a photosynthesis material in Triethanolamine (TEOA) solvent as an electron donor by time-resolved attenuated total reflection spectroscopy in the terahertz (THz) region. The spectrum of the complex in TEOA has an intermolecular vibrational mode between the complex and TEOA molecules, which reflects the precursor of the reductive quenching process. The intermolecular vibrational mode has three-step relaxation process in a picosecond timescale after photo-excitation, where firstly the triplet metal-to-ligand charge transfer excited state is vibrationally cooled down, secondly the distance between Re and TEOA is reduced by the rotation of TEOA molecules due to dipole-dipole interaction accelerated by heat transfer, and finally electrons transfer from TEOA to Re. These observations provide us the detailed information of the electron transfer process of photocatalytic properties of [Re(CO)2(bpy){P(OEt)3}2](PF6) in TEOA solvent.