Oscillatory features observed in two-dimensional electronic spectroscopy (2DES) manifest coherent vibrational and electronic dynamics and even the interplay of them. Recently, we developed a 2DES technique utilizing a pair of synchronized repetition-frequency-stabilized lasers, which enables the wide dynamic range measurements of 2DES signals rapidly. Here, we apply this dual-laser 2DES technique to investigate the electronic energy transfer (EET) process in bacterial light-harvesting complex II consisting of B800 and B850 circular aggregates at ambient temperature, and the coherent vibrational wavepakcet associated with the EET between the two aggregates are measured. Examining the principal component analysis of the time-resolved 2DES signal, we found that the EET from B800 to low-lying B850 states is modulated by a low-frequency (156 cm-1) vibrational mode of the exciton donor (B800). This observation suggests that the donor transition density is modulated by this vibration, which, in turn, modulates the energy transfer dynamics.
Bibliographical noteFunding Information:
This work was supported by the W. M. Keck Foundation through Award No. 1005586 (J.K. and G.D.S.) and by IBS-R023-D1 (M.C.). C.T.N. and R.J.C. were supported by BBRSC Grant No. BB/N016734/1. A.T.G. and R.J.C. gratefully acknowledge funding from the Photosynthetic Antenna Research Center, an Energy Frontier Research Center funded by the Department of Energy, Office of Science, Office of Basic Energy Sciences, under Award No. DE-SC0001035.
ASJC Scopus subject areas
- Materials Science(all)
- Physical and Theoretical Chemistry