Distinguishing packing configurations of molecular dimers using excited-state absorption peaks in two-dimensional electronic spectra
Abstract
Packing conformations of molecular aggregates are known to strongly influence the locations and intensities of spectral peaks. Here, we develop the third-order nonlinear spectroscopy signals for a purely electronic model of a molecular dimer, which is a prototype aggregate system. The model—which focuses on excited-state absorption (ESA) pathways in two-dimensional electronic spectra—reveals that orientational averaging leads to diagnostic ESA peak locations for H- and J-dimers. We constructed DNA-templated dimers of cyanine molecules as representative systems and used ultrabroadband two-dimensional electronic spectroscopy measurements to support the predicted signatures arising from the theoretical model. Fitting of steady-state spectra supports the assigned packing conformations. The results elucidate how ESA peaks can be diagnostic spectral signatures of packing conformation. This work lays the foundation for future studies that can include the complicating effects of vibronic states and additional electronic levels.
Article Details
Journal Info
The Journal of Chemical Physics
American Institute of Physics
Authors (17)
Matthew S. Barclay
Micron School of Materials Science and Engineering, Boise State University 1 , Boise, Idaho 83725,
Paul D. Cunningham
Electronics Science and Technology Division, Code 6800
Gissela Pascual
Micron School of Materials Science & Engineering
Simon K. Roy
Micron School of Materials Science & Engineering
Lance K. Patten
Micron School of Materials Science & Engineering
Kimihiro Susumu
Veronica R. Policht
Electronics Science and Technology Division Code 6800, U.S. Naval Research Laboratory 2 , Washington, District of Columbia 20375,
Divita Mathur
Adam Meares
Center for Biomolecular Science and Engineering Code 6900, U.S. Naval Research Laboratory 5 , Washington, District of Columbia 20375,
Jeunghoon Lee
Micron School of Materials Science & Engineering
Bernard Yurke
Micron School of Materials Science & Engineering
William B. Knowlton
Micron School of Materials Science & Engineering
Paul H. Davis
Micron School of Materials Science and Engineering, Boise State University 1 , Boise, Idaho 83725,
Ryan D. Pensack
Micron School of Materials Science and Engineering, Boise State University 1 , Boise, Idaho 83725,
Igor L. Medintz
Center for Biomolecular Science and Engineering, Code 6900
Joseph S. Melinger
Electronics Science and Technology Division, Code 6800
Daniel B. Turner
Micron School of Materials Science and Engineering, Boise State University 1 , Boise, Idaho 83725,