Quest for Luminescent Low‐Spin Chromium(I) Complexes with Doublet Metal‐to‐Ligand Charge‐Transfer Excited States
Abstract
AbstractTwo paramagnetic Cr(I) complexes with homoleptic fac‐bis(triarylisocyanide) ligands were prepared by chemical oxidation of the Cr(0) precursors and emission spectra with peak maximum at respective 568 and 525 nm have been recorded with THF solutions of these two low‐spin d5 metal complexes at 298 K. Structural, spectroscopic, and theoretical studies revealed that the emission of the Cr(I) complexes could be tentatively assigned to be spin‐allowed 2MLCT excited states. Femtosecond‐resolved transient absorption spectra confirmed that the lifetimes of the excited states were in the tens of picoseconds, which could be explained by the fast nonradiative decay of 2MLCT state through low‐lying quartet metal‐centered (4MC) states. The Cr(I) complexes with luminescent 2MLCT excited states were distinct from the previously reported d5 Fe(III) complexes with luminescent 2LMCT excited states, enriching the diversity of emissive excited states of earth‐abundant 3d transition metal complexes.
Article Details
Authors (10)
Mengwei Yue
Department of Chemistry Southern University of Science and Technology Shenzhen Guangdong 518055 P.R. China
Wai‐Pong To
Department of Chemistry The University of Hong Kong Pokfulam Road Hong Kong SAR P.R. China
Yifan Zhao
Qiushi Hu
SUSTech Energy Institute for Carbon Neutrality Department of Mechanical and Energy Engineering Southern University of Science and Technology Shenzhen Guangdong China
Xiaoyong Chang
Department of Chemistry Southern University of Science and Technology (SUSTech) Shenzhen China
Xihan Chen
Department of Mechanical and Energy Engineering
Xi‐ai Zhang
Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education Beijing Normal University Beijing 100875 P.R. China
Xuebo Chen
Liangliang Wu
Wei Lu