Abstract
Non-covalent interactions are rapidly gaining interest as they are often crucial in determining the properties of materials, and key to supramolecular chemistry and to biochemistry. Non-covalent Polycyclic Aromatic Hydrocarbon (PAH) complexes are in particular relevant to astrochemistry and combustion chemistry where they are involved in the initial steps of condensation and soot formation, respectively. Here, we investigated non-covalent π-π stacking and CH-π interactions in naphthalene and acenaphthene clusters using high-resolution IR-UV spectroscopy in combination with quantum chemical calculations. We identified spectral shifts that occur upon complexation and thereby evaluated predicted potential energy surfaces. Although theory predicts a blueshift, a redshift is observed for the aliphatic CH-π interactions in the experimental spectrum of acenaphthene upon dimerization, indicating that CH-π interaction indeed affects the aliphatic bonds, while a blueshift is predicted, consequently theory deserves attention here. The results provide strong indications for a prevalent parallel naphthalene dimer, showing that π-π stacking interactions become significant for bicyclic and larger PAHs.
Original language | English |
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Article number | e1811908 |
Journal | Molecular Physics |
Volume | 119 |
Issue number | 1-2 |
DOIs | |
Publication status | Published - 17 Jan 2021 |
Externally published | Yes |
Funding
This work was supported by The Netherlands Organization for Scientific Research (NWO) and is part of the Dutch Astrochemistry Network (DAN) II (Project No. 648.000.029). The authors thank the FELIX laboratory team for their experimental assistance and scientific support and also acknowledge the Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO) for the support of the FELIX Laboratory and SURFsara for their computational resources. This work was also supported by the ERC Starting grant ‘ASTROROT’, grant number 638027, and the Deutsche Forschungsgemeinschaft (SCHN1280/4-2, grant number 271359857) in the context of the priority program SPP 1807 ‘Control of London dispersion interactions in molecular chemistry’.
Funders | Funder number |
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Dutch Astrochemistry Network | 648.000.029 |
European Research Council | 638027 |
Deutsche Forschungsgemeinschaft | 271359857, SCHN1280/4-2 |
Nederlandse Organisatie voor Wetenschappelijk Onderzoek |
Keywords
- geometry
- infrared spectroscopy
- non-covalent
- PAH clusters
- π-π interactions