Publication
Title
Raman and ROA spectra of (-)- and (+)-2-Br-hexahelicene : experimental and DFT studies of a $\pi$-conjugated chiral system
Author
Abstract
 The Raman optical activity (ROA) spectra of both enantiomers of 2-Br-hexahelicene in chloroform solution have been measured in the range 1700-300 cm(-1). Density functional theory (DFT) calculations accurately reproduce the observed features. The most intense ROA features are also the most intense Raman features, in the region 1350-1400 cm(-1), and correspond to the so-called D-modes, which play a major role in coronene and other PAHs (polycyclic aromatic hydrocarbons). Together with a detailed analysis of the normal mode structure, the polarizability tensors for the intense Raman features are investigated and related to the principal characteristics of helicene systems, namely, chirality and pi-conjugation. Through electron-phonon coupling analysis, we propose a mechanism that justifies the intense ROA signals.
Language
English
Source (journal)
The journal of physical chemistry : B : condensed matter, materials, surfaces, interfaces and biophysical. - Washington, D.C.
Publication
Washington, D.C. : 2013
ISSN
1520-6106
1520-5207
Volume/pages
117:7(2013), p. 2221-2230
ISI
000315432200027
Full text (Publisher's DOI)
UAntwerpen
 Faculty/Department Research group Publication type Subject