論文

査読有り
2017年10月

Effects of phosphonate ester groups attached on a heteroleptic Ir(III) photosensitizer

JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
  • Atsushi Kobayashi
  • ,
  • Shuhei Watanabe
  • ,
  • Masanori Ebina
  • ,
  • Masaki Yoshida
  • ,
  • Masako Kato

347
開始ページ
9
終了ページ
16
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1016/j.jphotochem.2017.06.042
出版者・発行元
ELSEVIER SCIENCE SA

Two heteroleptic Ir(III) complexes bearing two diethyl phosphonate groups, [Ir(ppy-PE)(2)(bpy)(PF6) and [Ir(ppy)(2)(bpy-dPE)](PF6) (1pPE and 1bPE; Hppy = 2-phenylpyridine, Hppy-PE =4-(diethylphosphonomethyl)-2-phenylpyridine, bpy = 2,2'-bipyridine, bpy-dPE=4,4'-bis(diethylphosphonomethyl)-2,2'bipyridine), were successfully synthesized, and their photophysical properties were investigated by UV-vis absorption and emission spectroscopic and electrochemical measurements. Both IpPE and IbPE complexes exhibited similar IJV-vis absorption and emission spectra and cyclic voltammograms as those of nonmodified complex [Ir(ppy)2(bpy)](PF6) (1), indicating the suitability for photocatalytic H-2 evolution reaction. (MLCT)-M-3 emissions of both IbPE and 1pPE were quenched by electron transfer from triethylamine (TEA) sacrificial electron donor, but the quenching rate of IpPE was lower than that of nonmodified complex 1 and 1bPE. In contrast, the quenching rate of IbPE by an electron-accepting [Co (bpy)(3)](2+) moiety was slightly lower than 1 or IpPE. These results suggest that the two diethylphosphonate ester groups regulate the direction of photoinduced electron-transfer reaction at the (MLCT)-M-3 excited state due to their steric bulkiness. In addition, the photocatalytic activity for H-2 evolution in the presence of K2PtC14 precatalyst clearly showed remarkably extended longevity for both IpPE and 1bPE compared to that of 1, indicating that the two diethyl phosphonate groups attached on IpPE and IbPE also play an important role in the extended longevity of H-2-evolution activity of in-situ generated Pt colloidal catalyst from K2PtC14. The deactivation pathway of IpPE and 1bPE during photo H-2 evolution reaction is mainly due to the substitution of the bpy-type ligand by CH3CN solvent of the one electron reduced Ir(II) species like the non-substituted complex 1. (C) 2017 Elsevier B.V. All rights reserved.

Web of Science ® 被引用回数 : 4

リンク情報
DOI
https://doi.org/10.1016/j.jphotochem.2017.06.042
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000411546700002&DestApp=WOS_CPL