Simulating surface-enhanced Raman optical activity using atomistic electrodynamics-quantum mechanical models
Dhabih V. Chulhai, Lasse Jensen
Raman optical activity has proven to be a powerful tool for probing the geometry of small organic and biomolecules. It has therefore been expected that the same mechanisms responsible for surface-enhanced Raman scattering may allow for similar enhancements in surface-enhanced Raman optical activity (SEROA). However, SEROA has proved to be an experimental challenge and mirror-image SEROA spectra of enantiomers have so far not been measured. There exists a handful of theories to simulate SEROA, all of which treat the perturbed molecule as a point-dipole object. To go beyond these approximations, we present two new methods to simulate SEROA: the first is a dressed-tensors model that treats the molecule as a point-dipole and point-quadrupole object; the second method is the discrete interaction model/quantum mechanical (DIM/QM) model, which considers the entire charge density of the molecule. We show that although the first method is acceptable for small molecules, it fails for a medium-sized one such as 2-bromohexahelicene. We also show that the SEROA mode intensities and signs are highly sensitive to the nature of the local electric field and gradient, the orientation of the molecule, and the surface plasmon frequency width. Our findings give some insight into why experimental SEROA, and in particular observing mirror-image SEROA for enantiomers, has been difficult.
Journal of Physical Chemistry A
https://doi.org/10.1021/jp502107f
optical activity
Electrodynamics
Enantiomers
Tensors
Raman scattering
quadrupoles
Raman spectra
Chulhai, D. V., & Jensen, L. (2014). Simulating surface-enhanced Raman optical activity using atomistic electrodynamics-quantum mechanical models. Journal of Physical Chemistry A, 118(39), 9069-9079. https://doi.org/10.1021/jp502107f
Chulhai, Dhabih V. ; Jensen, Lasse. / Simulating surface-enhanced Raman optical activity using atomistic electrodynamics-quantum mechanical models. In: Journal of Physical Chemistry A. 2014 ; Vol. 118, No. 39. pp. 9069-9079.
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title = "Simulating surface-enhanced Raman optical activity using atomistic electrodynamics-quantum mechanical models",
abstract = "Raman optical activity has proven to be a powerful tool for probing the geometry of small organic and biomolecules. It has therefore been expected that the same mechanisms responsible for surface-enhanced Raman scattering may allow for similar enhancements in surface-enhanced Raman optical activity (SEROA). However, SEROA has proved to be an experimental challenge and mirror-image SEROA spectra of enantiomers have so far not been measured. There exists a handful of theories to simulate SEROA, all of which treat the perturbed molecule as a point-dipole object. To go beyond these approximations, we present two new methods to simulate SEROA: the first is a dressed-tensors model that treats the molecule as a point-dipole and point-quadrupole object; the second method is the discrete interaction model/quantum mechanical (DIM/QM) model, which considers the entire charge density of the molecule. We show that although the first method is acceptable for small molecules, it fails for a medium-sized one such as 2-bromohexahelicene. We also show that the SEROA mode intensities and signs are highly sensitive to the nature of the local electric field and gradient, the orientation of the molecule, and the surface plasmon frequency width. Our findings give some insight into why experimental SEROA, and in particular observing mirror-image SEROA for enantiomers, has been difficult.",
author = "Chulhai, {Dhabih V.} and Lasse Jensen",
doi = "10.1021/jp502107f",
journal = "Journal of Physical Chemistry A",
Chulhai, DV & Jensen, L 2014, 'Simulating surface-enhanced Raman optical activity using atomistic electrodynamics-quantum mechanical models', Journal of Physical Chemistry A, vol. 118, no. 39, pp. 9069-9079. https://doi.org/10.1021/jp502107f
Simulating surface-enhanced Raman optical activity using atomistic electrodynamics-quantum mechanical models. / Chulhai, Dhabih V.; Jensen, Lasse.
In: Journal of Physical Chemistry A, Vol. 118, No. 39, 02.10.2014, p. 9069-9079.
T1 - Simulating surface-enhanced Raman optical activity using atomistic electrodynamics-quantum mechanical models
AU - Chulhai, Dhabih V.
AU - Jensen, Lasse
N2 - Raman optical activity has proven to be a powerful tool for probing the geometry of small organic and biomolecules. It has therefore been expected that the same mechanisms responsible for surface-enhanced Raman scattering may allow for similar enhancements in surface-enhanced Raman optical activity (SEROA). However, SEROA has proved to be an experimental challenge and mirror-image SEROA spectra of enantiomers have so far not been measured. There exists a handful of theories to simulate SEROA, all of which treat the perturbed molecule as a point-dipole object. To go beyond these approximations, we present two new methods to simulate SEROA: the first is a dressed-tensors model that treats the molecule as a point-dipole and point-quadrupole object; the second method is the discrete interaction model/quantum mechanical (DIM/QM) model, which considers the entire charge density of the molecule. We show that although the first method is acceptable for small molecules, it fails for a medium-sized one such as 2-bromohexahelicene. We also show that the SEROA mode intensities and signs are highly sensitive to the nature of the local electric field and gradient, the orientation of the molecule, and the surface plasmon frequency width. Our findings give some insight into why experimental SEROA, and in particular observing mirror-image SEROA for enantiomers, has been difficult.
AB - Raman optical activity has proven to be a powerful tool for probing the geometry of small organic and biomolecules. It has therefore been expected that the same mechanisms responsible for surface-enhanced Raman scattering may allow for similar enhancements in surface-enhanced Raman optical activity (SEROA). However, SEROA has proved to be an experimental challenge and mirror-image SEROA spectra of enantiomers have so far not been measured. There exists a handful of theories to simulate SEROA, all of which treat the perturbed molecule as a point-dipole object. To go beyond these approximations, we present two new methods to simulate SEROA: the first is a dressed-tensors model that treats the molecule as a point-dipole and point-quadrupole object; the second method is the discrete interaction model/quantum mechanical (DIM/QM) model, which considers the entire charge density of the molecule. We show that although the first method is acceptable for small molecules, it fails for a medium-sized one such as 2-bromohexahelicene. We also show that the SEROA mode intensities and signs are highly sensitive to the nature of the local electric field and gradient, the orientation of the molecule, and the surface plasmon frequency width. Our findings give some insight into why experimental SEROA, and in particular observing mirror-image SEROA for enantiomers, has been difficult.
U2 - 10.1021/jp502107f
DO - 10.1021/jp502107f
JO - Journal of Physical Chemistry A
JF - Journal of Physical Chemistry A
Chulhai DV, Jensen L. Simulating surface-enhanced Raman optical activity using atomistic electrodynamics-quantum mechanical models. Journal of Physical Chemistry A. 2014 Oct 2;118(39):9069-9079. https://doi.org/10.1021/jp502107f
10.1021/jp502107f