TY - JOUR
T1 - Ring currents modulate optoelectronic properties of aromatic chromophores at 25 T
AU - Kudisch, Bryan
AU - Maiuri, Margherita
AU - Moretti, Luca
AU - Oviedo, Maria B.
AU - Wang, Leon
AU - Oblinsky, Daniel G.
AU - Prud'Homme, Robert K.
AU - Wong, Bryan M.
AU - McGill, Stephen A.
AU - Scholes, Gregory D.
N1 - Funding Information:
We acknowledge financial support by the National Science Foundation, MRI program (DMR-1229217), and by Princeton University through the Innovation Fund for New Ideas in the Natural Sciences. A portion of this work was performed at the National High Magnetic Field
Funding Information:
ACKNOWLEDGMENTS. We acknowledge financial support by the National Science Foundation, MRI program (DMR-1229217), and by Princeton University through the Innovation Fund for New Ideas in the Natural Sciences. A portion of this work was performed at the National High Magnetic Field
Funding Information:
Laboratory, which is supported by the National Science Foundation Co-operative Agreement DMR-1157490 and the State of Florida. M.M. acknowledges financial support by European Community (H2020 Marie Skłodowska-Curie Actions), Project 655059. M.B.O. acknowledges financial support by the National Science Foundation - Institute for Complex Adaptive Matter (NSF-ICAM) and the National Science Foundation for the use of supercomputing resources through the Extreme Science and Engineering Discovery Environment, Project TG-CHE140097 and acknowledges financial support by the Agencia Nacional de Promoción Científica y Tecnológica fondo para la Inves-tigación Científica y Tecnológica (ANPCyT-FONCyT, Grant PICT-2017-0795). B.M.W. acknowledges support from the US Department of Energy, Office of Science, Early Career Research Program under Award DE-SC0016269. B.K. acknowledges support by the National Science Foundation Graduate Research Fellowship under Grant DGE-1656466 as well as the Princeton Environmental Institute Walbridge Fund. B.K. thanks Istvan Pelczer for guidance and discussion with regard to the NMR spectroscopy and Kyra Schwarz and Bo Fu for careful reading of this manuscript.
Publisher Copyright:
© 2020 National Academy of Sciences. All rights reserved.
PY - 2020/5/26
Y1 - 2020/5/26
N2 - The properties of organic molecules can be influenced by magnetic fields, and these magnetic field effects are diverse. They range from inducing nuclear Zeeman splitting for structural determination in NMR spectroscopy to polaron Zeeman splitting organic spintronics and organic magnetoresistance. A pervasive magnetic field effect on an aromatic molecule is the aromatic ring current, which can be thought of as an induction of a circular current of π-electrons upon the application of a magnetic field perpendicular to the π-system of the molecule. While in NMR spectroscopy the effects of ring currents on the chemical shifts of nearby protons are relatively well understood, and even predictable, the consequences of these modified electronic states on the spectroscopy of molecules has remained unknown. In this work, we find that photophysical properties of model phthalocyanine compounds and their aggregates display clear magnetic field dependences up to 25 T, with the aggregates showing more drastic magnetic field sensitivities depending on the intermolecular interactions with the amplification of ring currents in stacked aggregates. These observations are consistent with ring currents measured in NMR spectroscopy and simulated in time-dependent density functional theory calculations of magnetic field-dependent phthalocyanine monomer and dimer absorption spectra. We propose that ring currents in organic semiconductors, which commonly comprise aromatic moieties, may present new opportunities for the understanding and exploitation of combined optical, electronic, and magnetic properties.
AB - The properties of organic molecules can be influenced by magnetic fields, and these magnetic field effects are diverse. They range from inducing nuclear Zeeman splitting for structural determination in NMR spectroscopy to polaron Zeeman splitting organic spintronics and organic magnetoresistance. A pervasive magnetic field effect on an aromatic molecule is the aromatic ring current, which can be thought of as an induction of a circular current of π-electrons upon the application of a magnetic field perpendicular to the π-system of the molecule. While in NMR spectroscopy the effects of ring currents on the chemical shifts of nearby protons are relatively well understood, and even predictable, the consequences of these modified electronic states on the spectroscopy of molecules has remained unknown. In this work, we find that photophysical properties of model phthalocyanine compounds and their aggregates display clear magnetic field dependences up to 25 T, with the aggregates showing more drastic magnetic field sensitivities depending on the intermolecular interactions with the amplification of ring currents in stacked aggregates. These observations are consistent with ring currents measured in NMR spectroscopy and simulated in time-dependent density functional theory calculations of magnetic field-dependent phthalocyanine monomer and dimer absorption spectra. We propose that ring currents in organic semiconductors, which commonly comprise aromatic moieties, may present new opportunities for the understanding and exploitation of combined optical, electronic, and magnetic properties.
KW - Aromatic ring currents
KW - Magnetic fields
KW - Ultrafast spectroscopy
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U2 - 10.1073/pnas.1918148117
DO - 10.1073/pnas.1918148117
M3 - Article
C2 - 32385159
AN - SCOPUS:85085467926
SN - 0027-8424
VL - 117
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 21
M1 - 11289
ER -