Rotational Spectra Of Adducts Of Pyridine With Methane And Its Halides

Gou, Qian

Permalink

https://hdl.handle.net/2142/51165 Copy

Description

Title

Rotational Spectra Of Adducts Of Pyridine With Methane And Its Halides

Author(s)

Gou, Qian

Contributor(s)

• Caminati, Walther
• Cocinero, Emilio J.
• Lesarri, Alberto
• Vallejo-López, Montserrat
• Spada, Lorenzo

Issue Date

2014-06-19

Keyword(s)

Clusters/Complexes

Abstract

The rotational spectra of the 1:1 complexes of pyridine (PYR) with methane and its halides have been observed and assigned using pulsed jet Fourier transform microwave technique. Depending on the nature of the chemical species linked to PYR, $\pi$ or $\sigma$ type complexes have been observed, in relation to the PYR interaction sites, that is the $\sigma$ system of the aromatic ring, or the n orbital of the nitrogen atom. In the case of PYR-\chem{CF_4}, where the two subunits are held together by a CF$_{3}$•••N halogen bond, with the top undergoing a free rotation with respect to PYR [1]. Instead, a C-Cl•••N halogen bond characterizes PYR-\chem{CF_3Cl}. In PYR with \chem{CHF_3} [2], \chem{CH_3F} and \chem{CH_2F_2} two kind of weak hydrogen bonds, C-H•••N and C-H•••F, have been found to connect the two constituent units. The barriers to the internal rotations of the \chem{CHF_3} and of the \chem{CH_3F} groups have been determined from the A-E splittings of the rotational transitions. The rotational spectrum of the adduct PYR-\chem{CH_4} shows that \chem{CH_4} links to an aromatic molecule through a C H•••$\pi$ weak hydrogen bond. The shape and the internal dynamic behavior of this complex are very similar to that of the van der Waals complexes involving aromatic molecules with rare gases, which would suggest classifying \chem{CH_4}, in relation to its ability to form molecular complexes with aromatic molecules, as a pseudo rare gas. References: [1] A. Maris, L. B. Favero, B. Velino, W. Caminati, J. Phys. Chem. A, 2013, 117, 11289. [2] L. B. Favero, B. M. Giuliano, A. Maris, S. Melandri, P. Ottaviani, B. Velino, W. Caminati, Chem. Eur. J. 2010, 16, 1761.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

English

Permalink

http://hdl.handle.net/2142/51165

DOI

https://doi.org/10.15278/isms.2014.RB05

Copyright and License Information

Copyright 2014 by the authors. Licensed under a Creative Commons Attribution 4.0 International License. http://creativecommons.org/licenses/by/4.0/

Owning Collections