Abstract
In this work we report on the experimental and theoretical investigations of the progressional complexation of the polycyclic aromatic hydrocarbon (PAH) acenaphthene with itself and with water. In the interstellar medium, PAH complexes are an important link between molecular gas and solid state configurations of carbon, and in the form of grains they are postulated to serve as chemical catalysts. However, no direct detection of PAHs or their (microhydrated) complexes in interstellar space has been achieved as of yet. Therefore, we provide UV and far-infrared ion dip spectra of homogeneous PAH multimers and their hydrated clusters. The far-IR region of the IR spectrum is especially interesting since it contains the most spectral features that arise due to complexation or microhydration. We present microhydrated PAH complexes up to the third order, where we show that the water clusters are locked with little perturbation on the different PAH platforms. Density functional theory (DFT) calculations involving hydrogen bond interactions still seem challenging for predicting the far-IR frequency range, although applying anharmonic corrections leads to slight improvements.
Original language | English |
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Pages (from-to) | 3414-3422 |
Number of pages | 9 |
Journal | Physical Chemistry Chemical Physics |
Volume | 21 |
Issue number | 7 |
DOIs | |
Publication status | Published - 1 Jan 2019 |
Externally published | Yes |
Funding
This work is supported via the Schwerpunktprogram SPP 1807 ‘‘Control of dispersion interactions in molecular chemistry’’ SCHN1280/4-2 and GR1927/13-1 and the ERC starting grant ‘ASTROROT’ (grant number 638027). A. L. S. was supported by ‘The Hamburg Centre for Ultrafast Imaging – Structure, Dynamics and Control of Matter at the Atomic Scale’ of the Deutsche Forschungsgemeinschaft via the Louise Johnson Fellowship. We would like to thank the FELIX laboratory team for their experimental assistance and we acknowledge the Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO) for the support of the FELIX Laboratory. Furthermore, the research leading to these results has received funding from LASERLAB-EUROPE (grant agreement no. 654148, European Union’s Horizon 2020 research and innovation program).
Funders | Funder number |
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Hamburg Centre for Ultrafast Imaging – Structure, Dynamics and Control of Matter | |
Horizon 2020 Framework Programme | 638027, 654148 |
European Research Council | |
Deutsche Forschungsgemeinschaft | |
Horizon 2020 |