A Heterodox Approach for Designing Iron Photosensitizers: Pentacyanoferrate(II) Complexes with Monodentate Bipyridinium/Pyrazinium-Based Acceptor Ligands

Date

2025-01-01

Author

Schmidt, Heiner
Oglou, Ramadan C.
Tunçer, Hüseyin O.
Ghobadi, Turkan G. U.
Tekir, Şafak
Sertcelik, Kubra N. O.
Ibrahim, Abdelrahman
Döhler, Lotta
Özçubukçu, Salih
Kupfer, Stephan
Dietzek-Ivanšić, Benjamin
Karadaş, Ferdi

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

55
views

0
downloads

Cite This

The main obstacle in replacing well-established precious ruthenium photosensitizers with earth-abundant iron analogs is the short excited state lifetimes of metal-to-ligand charge transfer (MLCT) states due to relatively weak octahedral field splitting and relaxation via metal-centered (MC) states. In this study, we address the issue of short lifetime by using pentacyanoferrate(II) complexes and combat facile photodissociation by utilizing positively charged pyrazinium or bipyridinium ligands. We utilize femtosecond transient absorption spectroscopy alongside quantum chemical calculations to probe the excited states of three 4,4′-bipyridinium- or pyrazinium-based pentacyanoferrate(II) complexes. The 4,4′-bipyridinium-based complexes exhibit 3MLCT lifetimes of about 20 ps, while the pyrazinium-based complex exhibits a lifetime of 61 ps in an aqueous solution, setting a benchmark for cyanoferrate complexes. These results mark the foundation for a new group of easy-to-prepare iron photosensitizers that can be used for harvesting visible light.

URI

https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=105001808479&origin=inward
https://hdl.handle.net/11511/114272

Collections

Department of Chemistry, Article