Vibrational Circular Dichroism Detects Symmetry Breaking due to Conformational Mobility in C2-Symmetry Chiral Molecules and Provides Further Insight into Inter-Chromophoric Interactions
| Autor: | David A. Lightner, Giovanna Longhi, Stefan E. Boiadjiev, Giuseppe Mazzeo, Sergio Abbate |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Circular dichroism
Physics and Astronomy (miscellaneous) Double bond General Mathematics Population C2-symmetry Infrared spectroscopy bicyclic diones 010402 general chemistry 01 natural sciences vibrational circular dichroism (VCD) electronic circular dichroism (ECD) density functional theory calculations (DFT) C-2-symmetry Bicyclic diones Density functional theory calculations (DFT) Electronic circular dichroism (ECD) Vibrational circular dichroism (VCD) 0103 physical sciences Computer Science (miscellaneous) Molecule Symmetry breaking education Conformational isomerism Physics chemistry.chemical_classification education.field_of_study 010304 chemical physics lcsh:Mathematics lcsh:QA1-939 0104 chemical sciences Crystallography chemistry Chemistry (miscellaneous) Vibrational circular dichroism |
| Zdroj: | Symmetry, Vol 12, Iss 1752, p 1752 (2020) Symmetry Volume 12 Issue 11 Symmetry (Basel) 12 (2020): 1752-1–1752-13. doi:10.3390/sym12111752 info:cnr-pdr/source/autori:Mazzeo, Giuseppe; Abbate, Sergio; Boiadjiev, Stefan E.; Lightner, David A.; Longhi, Giovanna/titolo:Vibrational Circular Dichroism Detects Symmetry Breaking due to Conformational Mobility in C-2-Symmetry Chiral Molecules and Provides Further Insight into Inter-Chromophoric Interactions/doi:10.3390%2Fsym12111752/rivista:Symmetry (Basel)/anno:2020/pagina_da:1752-1/pagina_a:1752-13/intervallo_pagine:1752-1–1752-13/volume:12 |
| ISSN: | 2073-8994 |
| DOI: | 10.3390/sym12111752 |
| Popis: | Bicyclo[3.3.1]nonane-2,6-dione (1) and bicyclo[3.3.1]nona-3,7-diene-2,6-dione (2) have been examined by vibrational circular dichroism (VCD), which, as for most C2-symmetric systems, exhibits strong VCD signals. In the case of 2, VCD signals are stronger and sharper with several bisignate doublets for 1, signals are less intense and broader. The VCD and IR spectra are excellently predicted by DFT calculations: only one conformer is present for 2, while for 1, three main conformers, related through concerted skeleton torsional motions are present (two of them being interchanged by C2-rotation). The VCD spectrum shows specific features for the different conformers, such that correct population factors are crucial for reproducing experimental data. Also, the TD-DFT prediction of ECD (electronic circular dichroism) spectra is good. By comparing the spectroscopic signature of the two molecules (both VCD and ECD) and by careful analysis of the theoretical results, the role of the C=C double bond in compound (2) is evidenced. The double bond contributes toward enhancing the CD response both electronically and vibrationally. |
| Databáze: | OpenAIRE |
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