Advanced

A Heteroleptic Ferrous Complex with Mesoionic Bis(1,2,3-triazol-5-ylidene) Ligands: Taming the MLCT Excited State of Iron(II).

Liu, Yizhu LU ; Kjaer, Kasper LU ; Fredin, Lisa LU ; Chabera, Pavel LU ; Harlang, Tobias LU ; Canton, Sophie LU ; Lidin, Sven LU ; Zhang, Jianxin LU ; Lomoth, Reiner and Bergquist, Karl-Erik LU , et al. (2015) In Chemistry: A European Journal 21(9). p.3628-3639
Abstract
Strongly σ-donating N-heterocyclic carbenes (NHCs) have revived research interest in the catalytic chemistry of iron, and are now also starting to bring the photochemistry and photophysics of this abundant element into a new era. In this work, The efficient synthesis of a heteroleptic Fe(II) complex (1) is based on sequentially furnishing the Fe(II) center with the benchmark 2,2'-bipyridine (bpy) ligand and the more strongly σ-donating mesoionic ligand, 4,4'-bis(1,2,3-triazol-5-ylidene) (btz). Complex 1 was comprehensively characterized by electrochemistry, static and ultrafast spectroscopy, and quantum chemical calculations and compared to [Fe(bpy)3 ](PF6 )2 and (TBA)2 [Fe(bpy)(CN)4 ]. Heteroleptic complex 1 extends the absorption... (More)
Strongly σ-donating N-heterocyclic carbenes (NHCs) have revived research interest in the catalytic chemistry of iron, and are now also starting to bring the photochemistry and photophysics of this abundant element into a new era. In this work, The efficient synthesis of a heteroleptic Fe(II) complex (1) is based on sequentially furnishing the Fe(II) center with the benchmark 2,2'-bipyridine (bpy) ligand and the more strongly σ-donating mesoionic ligand, 4,4'-bis(1,2,3-triazol-5-ylidene) (btz). Complex 1 was comprehensively characterized by electrochemistry, static and ultrafast spectroscopy, and quantum chemical calculations and compared to [Fe(bpy)3 ](PF6 )2 and (TBA)2 [Fe(bpy)(CN)4 ]. Heteroleptic complex 1 extends the absorption spectrum towards longer wavelengths compared to a previously synthesized homoleptic Fe(II) NHC complex. The combination of the mesoionic nature of btz and the heteroleptic structure effectively destabilizes the metal-centered (MC) states relative to the triplet metal-to-ligand charge transfer ((3) MLCT) state in 1, rendering it a lifetime of 13 ps, the longest to date of a photochemically stable Fe(II) complex. Deactivation of the (3) MLCT state is proposed to proceed via the (3) MC state that strongly couples with the singlet ground state. (Less)
Please use this url to cite or link to this publication:
author
, et al. (More)
(Less)
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Chemistry: A European Journal
volume
21
issue
9
pages
3628 - 3639
publisher
John Wiley & Sons
external identifiers
  • pmid:25504660
  • wos:000350116200019
  • scopus:84920059306
ISSN
1521-3765
DOI
10.1002/chem.201405184
language
English
LU publication?
yes
id
3ed9a5f0-c307-4fd0-9bc2-e9a9cb0aef8c (old id 4908360)
date added to LUP
2015-01-13 17:03:54
date last changed
2017-01-01 04:15:03
@article{3ed9a5f0-c307-4fd0-9bc2-e9a9cb0aef8c,
  abstract     = {Strongly σ-donating N-heterocyclic carbenes (NHCs) have revived research interest in the catalytic chemistry of iron, and are now also starting to bring the photochemistry and photophysics of this abundant element into a new era. In this work, The efficient synthesis of a heteroleptic Fe(II) complex (1) is based on sequentially furnishing the Fe(II) center with the benchmark 2,2'-bipyridine (bpy) ligand and the more strongly σ-donating mesoionic ligand, 4,4'-bis(1,2,3-triazol-5-ylidene) (btz). Complex 1 was comprehensively characterized by electrochemistry, static and ultrafast spectroscopy, and quantum chemical calculations and compared to [Fe(bpy)3 ](PF6 )2 and (TBA)2 [Fe(bpy)(CN)4 ]. Heteroleptic complex 1 extends the absorption spectrum towards longer wavelengths compared to a previously synthesized homoleptic Fe(II) NHC complex. The combination of the mesoionic nature of btz and the heteroleptic structure effectively destabilizes the metal-centered (MC) states relative to the triplet metal-to-ligand charge transfer ((3) MLCT) state in 1, rendering it a lifetime of 13 ps, the longest to date of a photochemically stable Fe(II) complex. Deactivation of the (3) MLCT state is proposed to proceed via the (3) MC state that strongly couples with the singlet ground state.},
  author       = {Liu, Yizhu and Kjaer, Kasper and Fredin, Lisa and Chabera, Pavel and Harlang, Tobias and Canton, Sophie and Lidin, Sven and Zhang, Jianxin and Lomoth, Reiner and Bergquist, Karl-Erik and Persson, Petter and Wärnmark, Kenneth and Sundström, Villy},
  issn         = {1521-3765},
  language     = {eng},
  number       = {9},
  pages        = {3628--3639},
  publisher    = {John Wiley & Sons},
  series       = {Chemistry: A European Journal},
  title        = {A Heteroleptic Ferrous Complex with Mesoionic Bis(1,2,3-triazol-5-ylidene) Ligands: Taming the MLCT Excited State of Iron(II).},
  url          = {http://dx.doi.org/10.1002/chem.201405184},
  volume       = {21},
  year         = {2015},
}