Issue 7, 2018

Pump–probe XAS investigation of the triplet state of an Ir photosensitizer with chromenopyridinone ligands

Abstract

The triplet excited state of a new Ir-based photosensitizer with two chromenopyridinone and one bipyridine-based ligands has been studied by pump–probe X-ray absorption near edge structure (XANES) spectroscopy coupled with DFT calculations. The excited state has a lifetime of 0.5 μs in acetonitrile and is characterized by very small changes of the local atomic structure with an average metal–ligand bond length change of less than 0.01 Å. DFT-based calculations allow the interpretation of the XANES in the energy range of ∼50 eV around the absorption edge. The observed transient XANES signal arises from an additional metal-centered Ir 5d vacancy in the excited state which appears as a result of electron transfer from the metal to the ligand. The overall energy shift of the excited state spectrum originates from the shift of 2p and unoccupied states induced by screening effects. The approach for the analysis of time-resolved spectra of 5d metal complexes is quite general and can also be used if excited and ground state structures are significantly different.

Graphical abstract: Pump–probe XAS investigation of the triplet state of an Ir photosensitizer with chromenopyridinone ligands

Supplementary files

Article information

Article type
Paper
Submitted
13 Cʼhwe. 2018
Accepted
12 Mae 2018
First published
14 Mae 2018

Photochem. Photobiol. Sci., 2018,17, 896-902

Pump–probe XAS investigation of the triplet state of an Ir photosensitizer with chromenopyridinone ligands

G. Smolentsev, K. M. van Vliet, N. Azzaroli, J. A. van Bokhoven, A. M. Brouwer, B. de Bruin, M. Nachtegaal and M. Tromp, Photochem. Photobiol. Sci., 2018, 17, 896 DOI: 10.1039/C8PP00065D

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Spotlight

Advertisements