Transition metal complexes with photoactive charge-transfer excited states are pervasive throughout the literature. In particular, [Ru(bpy) ] (bpy=2,2'-bipyridine), with its metal-to-ligand charge-transfer emission, has been established as a key complex. Meanwhile, interest in so-called spin-flip metal-centered states has risen dramatically after the molecular ruby [Cr(ddpd) ] (ddpd=N,N'-dimethyl-N,N'-dipyridin-2-yl-pyridine-2,6-diamine) led to design principles to access strong, long-lived emission from photostable chromium(III) complexes. This Review contrasts the properties of emissive charge-transfer and spin-flip states by using [Ru(bpy) ] and [Cr(ddpd) ] as prototypical examples. We discuss the relevant excited states, the tunability of their energy and lifetimes, and their response to external stimuli. Finally, we identify strengths and weaknesses of charge-transfer and spin-flip states in applications such as photocatalysis and circularly polarized luminescence.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1002/anie.202213207 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Engineering Magnetic Heterostructures with Synergistic Regulation of Charge-Transfer and Spin-Ordering for Enhanced Water Oxidation.
Adv Sci (Weinh)
November 2024
Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong, 2500, Australia.
The design of heterojunctions offers a crucial solution for energy conversion and storage challenges, but current research predominantly focuses on charge transfer benefits, often neglecting spin attribute regulation despite the increasing recognition of spin-sensitivity in many chemical reactions. In this study, a novel magnetic heterostructure, CoFeO@CoFeMoO, is designed to simultaneously modulate charge and spin characteristics, and systematically elucidated their synergistic impact on the oxygen evolution reaction (OER). Experimental results and density functional theory calculations confirmed that the magnetic heterostructure exhibits both charge transfer and spin polarization.
View Article and Find Full Text PDFModulatory spin-flip of triplet excitons diversiform electron-donating units for MR-TADF emitters towards solution-processed narrowband OLEDs.
Chem Sci
October 2024
Department Key Laboratory of Rubber-Plastics, Ministry of Education/Shandong Provincial Key Laboratory of Rubber-Plastics, School of Polymer Science and Engineering, Qingdao University of Science & Technology Qingdao 266042 P. R. China
Multiple resonance thermally activated delayed fluorescence (MR-TADF) molecules are emerging as promising candidates for high-resolution organic light-emitting diode (OLED) displays, but MR-TADF emitters always suffer from an unsatisfactory rate constant of reverse intersystem crossing ( ) due to inherently low spin orbital coupling strength between excited singlet and triplet states. Herein, we systematically investigate the long-range charge transfer (LRCT) and heavy-atom effects on modulating the excited state natures and energy levels integrating diversiform electron-donating units with the MR skeleton. Compared with unsubstituted analogues, newly designed MR-TADF emitters exhibit significantly boosted values and close-to-unity photoluminescence quantum yield especially for BuCzBN-PXZ (2.
View Article and Find Full Text PDFControlling Ultrafast Magnetization Dynamics via Coherent Phonon Excitation in a Ferromagnet Monolayer.
Nano Lett
October 2024
Department of Physical and Macromolecular Chemistry, Faculty of Science, Charles University, Prague 12843, Czech Republic.
Exploring ultrafast magnetization control in 2D magnets via laser pulses is established, yet the interplay between spin dynamics and the lattice remains underexplored. Utilizing real-time time-dependent density functional theory (rt-TDDFT) coupled with Ehrenfest dynamics and nonadiabatic molecular dynamics (NAMD) simulations, we systematically investigate the laser-induced spin-nuclei dynamics with pre-excited A and E coherent phonons in the 2D ferromagnet FeGeTe (FGT) monolayer. Selective pre-excitation of coherent phonons under ultrafast laser irradiation significantly alters the local spin moment of FGT, consequently inducing additional spin loss attributed to the nuclear motion-induced asymmetric interatomic charge transfer.
View Article and Find Full Text PDFN-Aromatic Complexation in Tetraphenyl Porphyrin Iron (III)-Pyridine: Evidence of Spin-Flip via Gas-Phase Electronic Spectroscopy.
Chemphyschem
December 2024
Department of Chemistry, University of York, Heslington, York, YO10 5DD, United Kingdom.
There is growing interest in the electronic properties of metalloporphyrins especially in relation to their interactions with other molecular species in their local environment. Here, UV-VIS laser photodissociation spectroscopy in vacuo has been applied to an iron-centred metalloporphyrin (FeTPP) and its N-aromatic adduct with pyridine (py) to determine the electronic effect of complexation. Both the metalloporphyrin (FeTPP) and pyridine adduct (FeTPP⋅py) absorb strongly across the spectral region studied (652-302 nm: 1.
View Article and Find Full Text PDFHighly efficient pure-blue organic light-emitting diodes based on rationally designed heterocyclic phenophosphazinine-containing emitters.
Nat Commun
July 2024
School of Chemical Engineering and Light Industry, Guangdong University of Technology Guangzhou, 510006, Guangzhou, P. R. China.
Article Synopsis
- Multi-resonance thermally activated delayed fluorophores are being researched for high-resolution applications due to their color purity, but face performance issues due to inefficient spin-flip processes.
- This study presents two novel pure-blue emitters using an organoboron multi-resonance core with a flexible donor, which enhances excited state density without losing color quality.
- By modifying the electronic structure through different phosphorus motifs, the emitters achieve a 20-fold increase in spin-flip efficiency, resulting in high-performance organic light-emitting diodes with a quantum efficiency of 37.6% and minimized efficiency roll-offs.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!