Structural change dynamics of heteroleptic Cu(i) complexes observed by ultrafast emission spectroscopy

Masashi Sanga, Kosuke Nakamura, Munetaka Iwamura*, Koichi Nozaki, Hiroyuki Takeda*, Yu Monma, Osamu Ishitani

*この論文の責任著者

研究成果: ジャーナルへの寄稿学術論文査読

5 被引用数 (Scopus)

抄録

[Cu(i)(dmp)(P)2]+ (dmp = 2,9-dimethyl-1,10-phenanthroline derivatives; P = phosphine ligand) is one of the most promising photosensitizers used in a photo-catalytic system for reducing CO2, for which the quantum yield is as high as 57%. In this work, time-resolved emission spectra of Cu(i) complexes in solutions were investigated using femtosecond fluorescence up-conversion and nanosecond time-resolved emission spectroscopic systems. The temporal profiles of emission intensities less than 10 ps in acetonitrile solution were reproduced using a tri-exponential function with three-time constants of 0.040 ps, 0.78 ps and 8.0 ps. We found that only the second time constant is dependent on the solvent (acetonitrile: 0.78 ps, butyronitrile: 1.4 ps), indicating that the 0.78 ps spectral change is attributed to the structural change of the Cu(i) complex. The oscillator strengths of transition species are derived from the intensities in the time-resolved emission spectra (species-associated spectra). Based on the oscillator strengths, we concluded that the 0.040 ps process is the Sn → S1 internal conversion and the 0.78 ps process is a structural change in the S1 state. The final time constant of 8.0 ps is assigned to the S1 → T1 intersystem crossing because the 3MLCT state (τT1 = 97 ns) is generated after the decay. The DFT calculation showed that the 0.78 ps spectral change (∼600 cm−1 redshift) is attributed to Jahn-Teller distortion around the metal center, and there is a large structural change in the ligand, which results in a large Stokes shift in the Sn state (7.3 × 103 cm−1).

本文言語英語
ページ(範囲)15873-15884
ページ数12
ジャーナルPhysical Chemistry Chemical Physics
25
23
DOI
出版ステータス出版済み - 2023/05/15

ASJC Scopus 主題領域

  • 物理学および天文学一般
  • 物理化学および理論化学

フィンガープリント

「Structural change dynamics of heteroleptic Cu(i) complexes observed by ultrafast emission spectroscopy」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。

引用スタイル