NON-COVALENT INTERACTIONS AND INTERNAL DYNAMICS IN PYRIDINE-AMMONIA: A COMBINED QUANTUM-CHEMICAL AND MICROWAVE SPECTROSCOPY STUDY

Puzzarini, Cristina

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https://hdl.handle.net/2142/96839 Copy

Description

Title

NON-COVALENT INTERACTIONS AND INTERNAL DYNAMICS IN PYRIDINE-AMMONIA: A COMBINED QUANTUM-CHEMICAL AND MICROWAVE SPECTROSCOPY STUDY

Author(s)

Puzzarini, Cristina

Contributor(s)

• Caminati, Walther
• Barone, Vincenzo
• Vazart, Fanny
• Tasinato, Nicola
• Spada, Lorenzo

Issue Date

6/22/2017

Keyword(s)

Clusters/Complexes

Abstract

The 1:1 complex of ammonia with pyridine has been characterized by using state-of-the-art quantum-chemical computations combined with pulsed-jet Fourier-Transform microwave spectroscopy. The computed potential energy landscape pointed out the formation of a stable $sigma$-type complex, which has been confirmed experimentally: the analysis of the rotational spectrum showed the presence of only one 1:1 pyridine – ammonia adduct. Each rotational transition is split into several components due to the internal rotation of NH$_3$ around its $C_3$ axis and to the hyperfine structure of both $^{14}$N quadrupolar nuclei, thus providing the unequivocal proof that the two molecules form a $sigma$-type complex involving both a N-H$cdots$N and a C-H$cdots$N hydrogen bond. The dissociation energy (BSSE and ZPE corrected) has been estimated to be 11.5 kJ$cdot$mol$^{-1}$. This work represents the first application of an accurate, yet efficient computational scheme, designed for the investigation of small biomolecules, to a molecular cluster.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

English

Permalink

http://hdl.handle.net/2142/96839

DOI

10.15278/isms.2017.RH08

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