Electric-Field-Induced Effects on the Dipole Moment and Vibrational Modes of the Centrosymmetric Indigo Molecule

0540047 - BFÚ 2021 RIV US eng J - Journal Article
Nardo, V. M. - Cassone, G. - Ponterio, R.C. - Saija, F. - Šponer, Jiří - Tommasini, M. - Trusso, S.
Electric-Field-Induced Effects on the Dipole Moment and Vibrational Modes of the Centrosymmetric Indigo Molecule.
Journal of Physical Chemistry A. Roč. 124, č. 51 (2020), s. 10856-10869. ISSN 1089-5639. E-ISSN 1520-5215
Institutional support: RVO:68081707
Keywords : enhanced raman-spectroscopy * single-molecule * electrostatic catalysis * aqueous-solutions * high-performance * spectra
OECD category: Atomic, molecular and chemical physics (physics of atoms and molecules including collision, interaction with radiation, magnetic resonances, Mössbauer effect)
Impact factor: 2.781, year: 2020
Method of publishing: Limited access
https://pubs.acs.org/doi/10.1021/acs.jpca.0c09791

Intense static electric fields can strongly perturb chemical bonds and induce frequency shifts of the molecular vibrations in the so-called vibrational Stark effect. Based on a density functional theory (DFT) approach, here, we report a detailed investigation of the influence of oriented external electric fields (OEEFs) on the dipole moment and infrared (IR) spectrum of the nonpolar centrosymmetric indigo molecule. When an OEEF as intense as similar to 0.1 V angstrom(-1) is applied, several modifications in the IR spectrum are observed. Besides the notable frequency shift of some modes, we observe the onset of new bands-forbidden by the selection rules in the zero-field case. Such a neat field-induced modification of the vibrational selection rules, and the subsequent variations of the peaks' intensities in the IR spectrum, paves the way toward the design of smart tools employing centrosymmetric molecules as proxies for mapping local electric fields. In fact, here, we show that the ratio between the IR and the Raman intensities of selected modes is proportional to the square of the local field. This indicator can be used to quantitatively measure local fields, not only in condensed matter systems under standard conditions but also in field-emitting-tip apparatus.
Permanent Link: http://hdl.handle.net/11104/0317716