Photophysics of Ruthenium(II) Complexes with Thiazole π-Extended Dipyridophenazine Ligands

Kaufmann M, Müller C, Cullen AA, Brandon MP, Dietzek B, Pryce MT (2021)


Publication Type: Journal article

Publication year: 2021

Journal

Book Volume: 60

Pages Range: 760-773

Journal Issue: 2

DOI: 10.1021/acs.inorgchem.0c02765

Abstract

Transition-metal-based donor-acceptor systems can produce long-lived excited charge-transfer states by visible-light irradiation. The novel ruthenium(II) polypyridyl type complexes Ru1 and Ru2 based on the dipyridophenazine ligand (L0) directly linked to 4-hydroxythiazoles of different donor strengths were synthesized and photophysically characterized. The excited-state dynamics were investigated by femtosecond-to-nanosecond transient absorption and nanosecond emission spectroscopy complemented by time-dependent density functional theory calculations. These results indicate that photoexcitation in the visible region leads to the population of both metal-to-ligand charge-transfer (1MLCT) and thiazole (tz)-induced intraligand charge-transfer (1ILCT) states. Thus, the excited-state dynamics is described by two excited-state branches, namely, the population of (i) a comparably short-lived phenazine-centered 3MLCT state (τ ≈ 150-400 ps) and (ii) a long-lived 3ILCT state (τ ≈ 40-300 ns) with excess charge density localized on the phenazine and tz moieties. Notably, the ruthenium(II) complexes feature long-lived dual emission with lifetimes in the ranges τEm,1 ≈ 40-300 ns and τEm,2 ≈ 100-200 ns, which are attributed to emission from the 3ILCT and 3MLCT manifolds, respectively.

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APA:

Kaufmann, M., Müller, C., Cullen, A.A., Brandon, M.P., Dietzek, B., & Pryce, M.T. (2021). Photophysics of Ruthenium(II) Complexes with Thiazole π-Extended Dipyridophenazine Ligands. Inorganic Chemistry, 60(2), 760-773. https://dx.doi.org/10.1021/acs.inorgchem.0c02765

MLA:

Kaufmann, Martin, et al. "Photophysics of Ruthenium(II) Complexes with Thiazole π-Extended Dipyridophenazine Ligands." Inorganic Chemistry 60.2 (2021): 760-773.

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