TY - JOUR
T1 - Ultrafast Two-Electron Transfer in a CdS Quantum Dot-Extended-Viologen Cyclophane Complex
AU - Young, Ryan M.
AU - Jensen, Stephen C.
AU - Edme, Kedy
AU - Wu, Yilei
AU - Krzyaniak, Matthew D.
AU - Vermeulen, Nicolaas A.
AU - Dale, Edward J.
AU - Stoddart, J. Fraser
AU - Weiss, Emily A.
AU - Wasielewski, Michael R.
AU - Co, Dick T.
N1 - Funding Information:
Spectroscopic studies (R.M.Y., D.T.C., S.C.J., K.E., E.A.W., and M.R.W.) were supported as part of the ANSER Center, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, under Award no. DE-SC0001059. N.A.V., E.J.D., and J.F.S. are part of the Joint Center of Excellence in Integrated Nano-Systems at the King Abdulaziz City for Science and Technology and Northwestern University (NU).
Publisher Copyright:
© 2016 American Chemical Society.
PY - 2016/5/18
Y1 - 2016/5/18
N2 - Time-resolved optical spectroscopies reveal multielectron transfer from the biexcitonic state of a CdS quantum dot to an adsorbed tetracationic compound cyclobis(4,4′-(1,4-phenylene) bipyridin-1-ium-1,4-phenylene-bis(methylene)) (ExBox4+) to form both the ExBox3+• and the doubly reduced ExBox2(+•) states from a single laser pulse. Electron transfer in the single-exciton regime occurs in 1 ps. At higher excitation powers the second electron transfer takes ∼5 ps, which leads to a mixture of redox states of the acceptor ligand. The doubly reduced ExBox2(+•) state has a lifetime of ∼10 ns, while CdS+•:ExBox3+• recombines with multiple time constants, the longest of which is ∼300 μs. The long-lived charge separation and ability to accumulate multiple charges on ExBox4+ demonstrate the potential of the CdS:ExBox4+ complex to serve as a platform for two-electron photocatalysis.
AB - Time-resolved optical spectroscopies reveal multielectron transfer from the biexcitonic state of a CdS quantum dot to an adsorbed tetracationic compound cyclobis(4,4′-(1,4-phenylene) bipyridin-1-ium-1,4-phenylene-bis(methylene)) (ExBox4+) to form both the ExBox3+• and the doubly reduced ExBox2(+•) states from a single laser pulse. Electron transfer in the single-exciton regime occurs in 1 ps. At higher excitation powers the second electron transfer takes ∼5 ps, which leads to a mixture of redox states of the acceptor ligand. The doubly reduced ExBox2(+•) state has a lifetime of ∼10 ns, while CdS+•:ExBox3+• recombines with multiple time constants, the longest of which is ∼300 μs. The long-lived charge separation and ability to accumulate multiple charges on ExBox4+ demonstrate the potential of the CdS:ExBox4+ complex to serve as a platform for two-electron photocatalysis.
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U2 - 10.1021/jacs.5b13386
DO - 10.1021/jacs.5b13386
M3 - Article
AN - SCOPUS:84971220423
VL - 138
SP - 6163
EP - 6170
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 19
ER -