Details

Autor(en) / Beteiligte

• Seidler, Bianca
• Tran, Jens H.
• Hniopek, Julian
• Traber, Philipp
• Görls, Helmar
• Gräfe, Stefanie
• Schmitt, Michael
• Popp, Jürgen
• Schulz, Martin
• Dietzek‐Ivanšić, Benjamin

Titel

Photophysics of Anionic Bis(4H‐imidazolato)CuI Complexes

Ist Teil von

• Chemistry : a European journal, 2022-12, Vol.28 (72), p.e202202697-n/a

Ort / Verlag

Weinheim: Wiley Subscription Services, Inc

Erscheinungsjahr

2022

Link zum Volltext

Quelle

Wiley Online Library - AutoHoldings Journals

Beschreibungen/Notizen

• In this paper, the photophysical behavior of four panchromatically absorbing, homoleptic bis(4H‐imidazolato)CuI complexes, with a systematic variation in the electron‐withdrawing properties of the imidazolate ligand, were studied by wavelength‐dependent time‐resolved femtosecond transient absorption spectroscopy. Excitation at 400, 480, and 630 nm populates metal‐to‐ligand charge transfer, intraligand charge transfer, and mixed‐character singlet states. The pump wavelength‐dependent transient absorption data were analyzed by a recently established 2D correlation approach. Data analysis revealed that all excitation conditions yield similar excited‐state dynamics. Key to the excited‐state relaxation is fast, sub‐picosecond pseudo‐Jahn‐Teller distortion, which is accompanied by the relocalization of electron density onto a single ligand from the initially delocalized state at Franck‐Condon geometry. Subsequent intersystem crossing to the triplet manifold is followed by a sub‐100 ps decay to the ground state. The fast, nonradiative decay is rationalized by the low triplet‐state energy as found by DFT calculations, which suggest perspective treatment at the strong coupling limit of the energy gap law. Homoleptic CuI 4H‐imidazolate complexes show a remarkably broad and intense absorption spectrum ranging from the UV to NIR. The excited state decay pathways of four complexes selected for their electron‐withdrawing and steric properties were studied by fs transient absorption spectroscopy and spectro‐electrochemistry. A model‐free 2D correlation approach was applied for data evaluation.