Fluorescence-detected two-dimensional electronic spectroscopy (F-2DES) projects the third-order non-linear polarization in a system as an excited electronic state population which is incoherently detected as fluorescence. Multiple variants of F-2DES have been developed. However, none have demonstrated analysis of kinetics and coherences routine in photon-echo 2DES. Here, we report phase-modulated F-2DES measurements on a strongly coupled symmetric bacteriochlorin dyad, a relevant 'toy' model for photosynthetic energy and charge transfer. Coherence map analysis shows that the strongest frequency observed in the dyad is well-separated from the excited state electronic energy gap, and is consistent with a vibrational frequency readily observed in bacteriochlorin monomers. Kinetic rate maps show a picosecond relaxation timescale between the excited states of the dyad. To our knowledge this is the first demonstration of coherence and kinetic analysis using any variant of F-2DES.
Cite
@article{arxiv.1806.00896,
title = {Strongly Coupled Bacteriochlorophyll Dyad Studied Using Two-dimensional Phase-modulated Fluorescence-detected Electronic Spectroscopy},
author = {Vivek Tiwari and Yassel Acosta Matutes and Zhanqian Yu and Marcin Ptaszek and David F. Bocian and Dewey Holten and Christine Kirmaier and Arkaprabha Konar and Jennifer P. Ogilvie},
journal= {arXiv preprint arXiv:1806.00896},
year = {2018}
}