Vibrational Spectroscopy Of Benzonitrile–(water)1–2 Clusters In Helium Droplets

Khatri, Jai

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https://hdl.handle.net/2142/116592 Copy

Description

Title

Vibrational Spectroscopy Of Benzonitrile–(water)1–2 Clusters In Helium Droplets

Author(s)

Khatri, Jai

Contributor(s)

• Havenith, Martina
• Schwaab, Gerhard
• Chatterjee, Kuntal
• Roy, Tarun Kumar

Issue Date

2022-06-22

Keyword(s)

Clusters/Complexes

Abstract

Polycyclic aromatic hydrocarbons are considered as primary carriers of the unidentified interstellar bands. The recent discovery of the first interstellar aromatic molecule, benzonitrile (C$_6$H$_5$CN), suggests a repository of aromatic hydrocarbons in the outer earth environment. Herein, we report an infrared (IR) study of benzonitrile–(D$_{2}$O)$_n$ clusters using mass-selective detection in helium nanodroplets. In this work, we use isotopically substituted water, D$_2$O, instead of (H$_{2}$O) because of our restricted IR frequency range (2565–3100 \wn). A comparison of the experimental and predicted spectra computed at the MP2/6-311++G(d,p) level of benzonitrile–(water)$_{1–2}$ clusters reveals the formation of a unique local minimum structure, which was not detected in previous gas-phase molecular beam experiments. Here, the solvent water forms a nearly linear hydrogen bond (H-bond) with the nitrile nitrogen of benzonitrile, while the previously reported most stable cyclic H-bonded isomer is not observed. This can be rationalized by the stepwise aggregation process of precooled monomers. The addition of a second water molecule results in the formation of two different isomers. In one of the observed isomers, a H-bonded water chain binds linearly to the nitrile nitrogen similar to the monohydrated benzonitrile–water complex. In the other observed isomer, the water dimer forms a ring-type structure, where a H-bonded water dimer simultaneously interacts with the nitrile nitrogen and the adjacent ortho CH group. Finally, we compare the water-binding motif in the neutral benzonitrile–water complex with the corresponding positively and negatively charged benzonitrile–water monohydrates to comprehend the charge-induced alteration of the solvent binding motif.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

eng

Handle URL

https://hdl.handle.net/2142/116592

DOI

https://doi.org/10.15278/isms.2022.WD08

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Copyright 2022 held by the authors

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