Theory of the absorption and circular dichroism spectra of helical molecular aggregates

2007 ◽  
Vol 126 (10) ◽  
pp. 104904 ◽  
Author(s):  
A. Eisfeld ◽  
R. Kniprath ◽  
J. S. Briggs
Keyword(s):  
Circular Dichroism ◽  
Molecular Aggregates ◽  
Circular Dichroism Spectra ◽  
Circular Dichroïsm

scholarly journals Absorption and Circular Dichroism Spectra of Molecular Aggregates with the Full Cumulant Expansion.

2020 ◽  
Author(s):  
Lorenzo Cupellini ◽  
Filippo Lipparini ◽  
Jianshu Cao
Keyword(s):  
Circular Dichroism ◽  
Purple Bacteria ◽  
Spectroscopic Techniques ◽  
Molecular Aggregates ◽  
Cumulant Expansion ◽  
Circular Dichroism Spectra ◽  
Linear Absorption ◽  
Redfield Theory ◽  
Vibronic Sideband ◽  
Circular Dichroïsm

The exciton Hamiltonian of multichromophoric aggregates can be probed by spectroscopic techniques such as linear absorption and circular dichroism. In order to compare calculated Hamiltonians to experiments, a lineshape theory is needed, which takes into account the coupling of the excitons with inter- and intramolecular vibrations. This coupling is normally introduced in a perturbative way through the cumulant expansion formalism, and further approximated by assuming a Markovian exciton dynamics, for example with the modified Redfield theory.<br><br>Here we present an implementation of the full cumulant expansion (FCE) formalism [Ma and Cao, <i>J. Chem. Phys.</i> <b>2015</b>, 142, 094106 ] to efficiently compute absorption and circular dichroism spectra of molecular aggregates beyond the Markov approximation, without restrictions on the form of the exciton-phonon coupling. By employing the LH2 system of purple bacteria as a challenging test case, we compare the FCE lineshapes with the Markovian lineshapes obtained with the modified Redfield theory, showing that the latter present a much poorer agreement with experiments. The FCE approach instead accurately describes the lineshapes, especially in the vibronic sideband of the B800 peak. We envision that the FCE approach will become a valuable tool for accurately comparing model exciton Hamiltonians with optical spectroscopy experiments.

scholarly journals Absorption and Circular Dichroism Spectra of Molecular Aggregates with the Full Cumulant Expansion.

2020 ◽  
Author(s):  
Lorenzo Cupellini ◽  
Filippo Lipparini ◽  
Jianshu Cao
Keyword(s):  
Circular Dichroism ◽  
Purple Bacteria ◽  
Spectroscopic Techniques ◽  
Molecular Aggregates ◽  
Cumulant Expansion ◽  
Circular Dichroism Spectra ◽  
Linear Absorption ◽  
Redfield Theory ◽  
Vibronic Sideband ◽  
Circular Dichroïsm

The exciton Hamiltonian of multichromophoric aggregates can be probed by spectroscopic techniques such as linear absorption and circular dichroism. In order to compare calculated Hamiltonians to experiments, a lineshape theory is needed, which takes into account the coupling of the excitons with inter- and intramolecular vibrations. This coupling is normally introduced in a perturbative way through the cumulant expansion formalism, and further approximated by assuming a Markovian exciton dynamics, for example with the modified Redfield theory.<br><br>Here we present an implementation of the full cumulant expansion (FCE) formalism [Ma and Cao, <i>J. Chem. Phys.</i> <b>2015</b>, 142, 094106 ] to efficiently compute absorption and circular dichroism spectra of molecular aggregates beyond the Markov approximation, without restrictions on the form of the exciton-phonon coupling. By employing the LH2 system of purple bacteria as a challenging test case, we compare the FCE lineshapes with the Markovian lineshapes obtained with the modified Redfield theory, showing that the latter present a much poorer agreement with experiments. The FCE approach instead accurately describes the lineshapes, especially in the vibronic sideband of the B800 peak. We envision that the FCE approach will become a valuable tool for accurately comparing model exciton Hamiltonians with optical spectroscopy experiments.

Circular dichroism spectra of adsorbed dye-aggregates

1968 ◽  
Vol 65 ◽  
pp. 146-151 ◽  
Author(s):  
G. Scheibe ◽  
O. Wörz ◽  
F. Haimerl ◽  
W. Seiffert ◽  
J. Winkler
Keyword(s):  
Circular Dichroism ◽  
Circular Dichroism Spectra ◽  
Circular Dichroïsm

scholarly journals Natural and magnetic circular dichroism spectra of nucleosides: effect of the dynamics and environment

RSC Advances ◽  
2021 ◽  
Vol 11 (14) ◽  
pp. 8411-8419
Author(s):  
Jakub Kaminský ◽  
Valery Andrushchenko ◽  
Petr Bouř
Keyword(s):  
Molecular Dynamics ◽  
Circular Dichroism ◽  
Nucleic Acids ◽  
Electronic Absorption ◽  
Magnetic Circular Dichroism ◽  
Circular Dichroism Spectra ◽  
Circular Dichroïsm ◽  
Magnetic Circular Dichroism Spectra

Electronic absorption, natural and magnetic circular dichroism spectra of several nucleosides are simulated to understand their dependence on molecular dynamics and environment, their sensitivity to nucleoside pairing and stacking in nucleic acids.

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