Abstract
Long-lived quantum coherence between excited electronic states can enable highly efficient energy and charge transport processes in chemical systems. Recent pump-probe experiments on binuclear platinum complexes identified persistent, periodic beating of transient absorption anisotropy signals, indicating long excited-state coherence lifetimes. Our previous simulations of the electronic dynamics of these complexes indicate that coherence lifetimes are sensitive to the balance between competitive electronic couplings. The complexes with shorter Pt-Pt distances underwent no appreciable dephasing in the limit of static nuclei, motivating the inclusion of nuclear motion into our simulations. The tert-butyl-substituted complex is studied in this work using the Ehrenfest method for mixed quantum-classical dynamics to investigate the role of vibrational dynamics on a complex shown to support long coherence lifetimes. Results indicate that the inclusion of excited-state vibrations drives a rapid collapse of the two-state coherence prior to the experimentally determined intersystem crossing. This further suggests singlet excited-state coherences may not be prerequisites for long-lived triplet coherences.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 5071-5077 |
| Number of pages | 7 |
| Journal | Journal of Physical Chemistry A |
| Volume | 122 |
| Issue number | 23 |
| DOIs | |
| State | Published - Jun 14 2018 |
Funding
This work was supported by the Ultrafast Initiative of the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, through Argonne National Laboratory under Contract No. DE-AC02-06CH11357. The development of time-dependent electronic structure methods and software is supported by the National Science Foundation (CHE-1565520 and OAC-1663636 to X.L.). Computations were facilitated through the use of advanced computational, storage, and networking infrastructure provided by the Hyak supercomputer system at the University of Washington, funded by the Student Technology Fee and the National Science Foundation (MRI-1624430). L.X.C. are grateful for the support from the National Science Foundation (CHE-1363007 to L.X.C). F.N.C. was supported by the National Science Foundation (CHE-1665033). Xiaosong Li is the Harry and Catherine Jaynne Boand Endowed Professor of Chemistry at the University of Washington. His research focuses on developing and applying time-dependent relativistic and nonrelativistic electronic structure theories for studying excited-state chemical processes that underpin energy conversion, photocatalysis, and ultrafast spectroscopies. After completing his undergraduate studies at the University of Science and Technology of China in 1999, Li attended graduate school and received his Ph.D. in 2003 from the Wayne State University where he worked with Professor Bernhard Schlegel. He pursued his postdoctoral work at the Yale University with Prof. John C. Tully on nonadiabatic electron−nuclear dynamics. Li joined the University of Washington as Assistant Professor in the fall of 2005 and was promoted to Associate Professor in 2011 and to Full Professor in 2015. He has received awards that include the Sloan Research Fellowship, NSF CAREER Award, and ACS Open-Eye Outstanding Junior Faculty Award.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry