학술논문
Femtosecond X‑ray Spectroscopy Directly Quantifies Transient Excited-State Mixed Valency
Document Type
article
Author
Liekhus-Schmaltz, Chelsea; Fox, Zachary W; Andersen, Amity; Kjaer, Kasper S; Alonso-Mori, Roberto; Biasin, Elisa; Carlstad, Julia; Chollet, Matthieu; Gaynor, James D; Glownia, James M; Hong, Kiryong; Kroll, Thomas; Lee, Jae Hyuk; Poulter, Benjamin I; Reinhard, Marco; Sokaras, Dimosthenis; Zhang, Yu; Doumy, Gilles; March, Anne Marie; Southworth, Stephen H; Mukamel, Shaul; Cordones, Amy A; Schoenlein, Robert W; Govind, Niranjan; Khalil, Munira
Source
The Journal of Physical Chemistry Letters. 13(1)
Subject
Language
Abstract
Quantifying charge delocalization associated with short-lived photoexcited states of molecular complexes in solution remains experimentally challenging, requiring local element specific femtosecond experimental probes of time-evolving electron transfer. In this study, we quantify the evolving valence hole charge distribution in the photoexcited charge transfer state of a prototypical mixed valence bimetallic iron-ruthenium complex, [(CN)5FeIICNRuIII(NH3)5]-, in water by combining femtosecond X-ray spectroscopy measurements with time-dependent density functional theory calculations of the excited-state dynamics. We estimate the valence hole charge that accumulated at the Fe atom to be 0.6 ± 0.2, resulting from excited-state metal-to-metal charge transfer, on an ∼60 fs time scale. Our combined experimental and computational approach provides a spectroscopic ruler for quantifying excited-state valency in solvated complexes.