Ultrafast photophysics of para-substituted 2,5-bis(arylethynyl) rhodacyclopentadienes: thermally activated intersystem crossing

被引：1

作者：

Guo, Zilong ^{[2
]}

Wang, Yaxin ^{[2
]}

Heitmueller, Julia ^{[1
]}

Sieck, Carolin ^{[3
]}

Pruefer, Andreas ^{[4
]}

Ralle, Philipp ^{[4
]}

Steffen, Andreas ^{[4
]}

Henke, Petr ^{[5
,7
]}

Ogilby, Peter R. ^{[5
]}

Marder, Todd B. ^{[3
,6
]}

Ma, Xiaonan ^{[1
,2
]}

Brixner, Tobias ^{[1
,6
]}

机构：

[1] Julius Maximilians Univ Wurzburg, Inst Phys & Theoret Chem, Hubland, D-97074 Wurzburg, Germany

[2] Tianjin Univ, Inst Mol Plus, Tianjin 300072, Peoples R China

[3] Julius Maximilians Univ Wurzburg, Inst Anorgan Chem, Hubland, D-97074 Wurzburg, Germany

[4] TU Dortmund Univ, Dept Chem & Chem Biol, Otto Hahn Str 6, D-44227 Dortmund, Germany

[5] Aarhus Univ, Dept Chem, DK-8000 Aarhus, Denmark

[6] Julius Maximilians Univ Wurzburg, Inst Sustainable Chem & Catalysis Boron ICB, Hubland, D-97074 Wurzburg, Germany

[7] Charles Univ Prague, Fac Sci, Hlavova 2030, Prague 2, Czech Republic

来源：

CHEMICAL SCIENCE | 2024年 / 15卷 / 36期

基金：

国家重点研发计划;

关键词：

DELAYED FLUORESCENCE; VIBRATIONAL-ENERGY; MOLECULAR-OXYGEN; QUANTUM YIELDS; SINGLET; COMPLEXES; DYNAMICS; STATES; DEPENDENCE; LIFETIMES;

D O I：

10.1039/d4sc04306e

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

2,5-Bis(phenylethynyl) rhodacyclopentadienes (RCPDs), as a type of Rh(iii) complex, exhibit unusually intense fluorescence and slow intersystem crossing (ISC) due to weak metal-ligand interactions. However, details on their ultrafast photophysics and ISC dynamics are limited. In this work, electronic relaxation upon photoexcitation of two substituted RCPDs with two -CO2Me (A-RC-A) or -NMe2/-CO2Me (D-RC-A) end groups are comprehensively investigated using femtosecond transient absorption spectroscopy and theoretical analysis. Upon ultraviolet and visible excitation, dephasing of vibrational coherence, charge transfer, conformation relaxation, and ISC are observed experimentally. By calculating the spin-orbit coupling, reorganization energy, and adiabatic energy gap of plausible ISC channels, semi-classical Marcus theory revealed the dominance of thermally activated ISC (S-1 -> T-2) for both D-RC-A and A-RC-A, while S-1 -> T-1 channels are largely blocked due to high ISC barriers. With weak spin-orbit coupling, such differences in plausible ISC channels are predominately tuned by energetic parameters. Singlet oxygen sensitization studies of A-RC-A provide additional insight into the excited-state behavior of this complex.

引用

页码：14746 / 14756

页数：11