Ru Monoimines with Extended Excited-State Lifetimes and Geometrical Modulation of Photoinduced Mixed-Valence Interactions

Ramirez-Wierzbicki I, Pieslinger GE, Aramburu-Troselj BM, Abate PO, Cadranel A (2023)

Publication Type: Journal article

Publication year: 2023

Journal

Inorganic Chemistry American Chemical Society

Book Volume: 62

Pages Range: 3808-3816

Journal Issue: 9

DOI: 10.1021/acs.inorgchem.2c04054

Abstract

The photophysical properties of monodentate-imine ruthenium complexes do not usually fulfil the requirements for supramolecular solar energy conversion schemes. Their short excited-state lifetimes, like the 5.2 ps metal-to-ligand charge transfer (MLCT) lifetime of [Ru(py)4Cl(L)]+ with L = pz (pyrazine), preclude bimolecular or long-range photoinduced energy or electron transfer reactions. Here, we explore two strategies to extend the excited-state lifetime, based on the chemical modification of the distal N atom of pyrazine. On one hand, we used L = pzH+, where protonation stabilized MLCT states, rendering thermal population of MC states less favorable. On the other hand, we prepared a symmetric bimetallic arrangement in which L = {(μ-pz)Ru(py)4Cl} to enable hole delocalization via photoinduced mixed-valence interactions. A lifetime extension of 2 orders of magnitude is accomplished, with charge transfer excited states living 580 ps and 1.6 ns, respectively, reaching compatibility with bimolecular or long-range photoinduced reactivity. These results are similar to those obtained with Ru pentaammine analogues, suggesting that the strategy employed is of general applicability. In this context, the photoinduced mixed-valence properties of the charge transfer excited states are analyzed and compared with those of different analogues of the Creutz-Taube ion, demonstrating a geometrical modulation of the photoinduced mixed-valence properties.

Authors with CRIS profile

Alejandro Cadranel

Involved external institutions

Universidad de Buenos Aires (UBA) / University of Buenos Aires AR Argentina (AR)

How to cite

APA:

Ramirez-Wierzbicki, I., Pieslinger, G.E., Aramburu-Troselj, B.M., Abate, P.O., & Cadranel, A. (2023). Ru Monoimines with Extended Excited-State Lifetimes and Geometrical Modulation of Photoinduced Mixed-Valence Interactions. Inorganic Chemistry, 62(9), 3808-3816. https://dx.doi.org/10.1021/acs.inorgchem.2c04054

MLA:

Ramirez-Wierzbicki, Ivana, et al. "Ru Monoimines with Extended Excited-State Lifetimes and Geometrical Modulation of Photoinduced Mixed-Valence Interactions." Inorganic Chemistry 62.9 (2023): 3808-3816.

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