Quantum coherence in ultrafast photo-driven charge separation

Brian T. Phelan, Jonathan D. Schultz, Jinyuan Zhang, Guan Jhih Huang, Ryan M. Young, Michael R Wasielewski

Research output: Contribution to journalArticle

Abstract

Coherent interactions are prevalent in photodriven processes, ranging from photosynthetic energy transfer to superexchange-mediated electron transfer, resulting in numerous studies aimed towards identifying and understanding these interactions. A key motivator of this interest is the non-statistical scaling laws that result from coherently traversing multiple pathways due to quantum interference. To that end, we employed ultrafast transient absorption spectroscopy to measure electron transfer in two donor-acceptor molecular systems comprising a p-(9-anthryl)-N,N-dimethylaniline chromophore/electron donor and either one or two equivalent naphthalene-1,8:4,5-bis(dicarboximide) electron acceptors at both ambient and cryogenic temperatures. The two-acceptor compound shows a statistical factor of 2.1 ± 0.2 rate enhancement at room temperature and a non-statistical factor of 2.6 ± 0.2 rate enhancement at cryogenic temperatures, suggesting correlated interactions between the two acceptors with the donor and with the bath modes. Comparing the charge recombination rates indicates that the electron is delocalized over both acceptors at low temperature but localized on a single acceptor at room temperature. These results highlight the importance of shielding the system from bath fluctuations to preserve and ultimately exploit the coherent interactions.

Original languageEnglish
Pages (from-to)319-338
Number of pages20
JournalFaraday Discussions
Volume216
DOIs
Publication statusPublished - Jan 1 2019

Fingerprint

polarization (charge separation)
Electrons
cryogenic temperature
baths
electron transfer
Cryogenics
interactions
Temperature
electrons
augmentation
room temperature
naphthalene
scaling laws
chromophores
ambient temperature
Scaling laws
shielding
Chromophores
absorption spectroscopy
Absorption spectroscopy

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry

Cite this

Phelan, B. T., Schultz, J. D., Zhang, J., Huang, G. J., Young, R. M., & Wasielewski, M. R. (2019). Quantum coherence in ultrafast photo-driven charge separation. Faraday Discussions, 216, 319-338. https://doi.org/10.1039/c8fd00218e

Quantum coherence in ultrafast photo-driven charge separation. / Phelan, Brian T.; Schultz, Jonathan D.; Zhang, Jinyuan; Huang, Guan Jhih; Young, Ryan M.; Wasielewski, Michael R.

In: Faraday Discussions, Vol. 216, 01.01.2019, p. 319-338.

Research output: Contribution to journalArticle

Phelan, BT, Schultz, JD, Zhang, J, Huang, GJ, Young, RM & Wasielewski, MR 2019, 'Quantum coherence in ultrafast photo-driven charge separation', Faraday Discussions, vol. 216, pp. 319-338. https://doi.org/10.1039/c8fd00218e
Phelan, Brian T. ; Schultz, Jonathan D. ; Zhang, Jinyuan ; Huang, Guan Jhih ; Young, Ryan M. ; Wasielewski, Michael R. / Quantum coherence in ultrafast photo-driven charge separation. In: Faraday Discussions. 2019 ; Vol. 216. pp. 319-338.
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