The University of Southampton
University of Southampton Institutional Repository

Experimental and theoretical studies of unstable species

Experimental and theoretical studies of unstable species
Experimental and theoretical studies of unstable species

The work presented in this thesis is concerned with the study of unstable species using both experimental and theoretical methods. The experimental studies are described in Chapters 2 to 4, and the theoretical ab initio methods are considered in Chapters 5 and 6.

Structured spectra of the à and C̃; states of Kr·NO have been obtained using one-colour and two-colour resonance-enhanced multiphoton ionisation spectroscopy. Estimates of the dissociation energies of both complexes are given. The appearance of spectra in both the Kr·NO+ and Kr+ mass channels was investigated, and mechanisms for the formation of Kr+ ions are discussed. Spectra of the à state of the Ar·NO complex are also presented. The non-Rydberg behaviour of the à states of Ar·NO and Kr·NO is discussed.

Constant ionic state spectra of carbon monosulphide are presented in the photon energy range 11.3 - 20 electron volts using synchrotron radiation. The spectra, recorded using several vibrational components of the ground ionic state of CS have been assigned using quantum defect analysis.

In Chapter 4, results obtained by scattering laser and synchrotron radiation off pulsed free jet expansions of Ar and N2O are presented. The results are interpreted in terms of Rayleigh scattering from clusters formed within the free jet. Information on the relative size of clusters formed is obtained and compared to literature data. Where synchrotron radiation was used, contributions from non-Rayleigh scattering processes are considered.

ab initio molecular orbital calculations on the NO2+·X (X=H2O, N2, CO2) series of complexes are reported in Chapter 5. Optimised geometries and vibrational frequencies, as well as computed total energies have been used to calculate standard enthalpies, entropies and free energies for the complexing and ligand-switching reactions between the three molecular complexes. The results obtained have been compared to previous experimental and theoretical values where available.

The intermolecular potential energy surface of the Ar·NO+ cationic complex has been calculated using ab initio molecular orbital calculations. The effect of level of theory, basis set, NO+ bond length and basis set superposition error was investigated. The calculated surfaces were used to obtain intermolecular vibrational frequencies, which were compared to previous calculations and experimental results.

University of Southampton
Bush, Andrew Marcus
Bush, Andrew Marcus

Bush, Andrew Marcus (1997) Experimental and theoretical studies of unstable species. University of Southampton, Doctoral Thesis.

Record type: Thesis (Doctoral)

Abstract

The work presented in this thesis is concerned with the study of unstable species using both experimental and theoretical methods. The experimental studies are described in Chapters 2 to 4, and the theoretical ab initio methods are considered in Chapters 5 and 6.

Structured spectra of the à and C̃; states of Kr·NO have been obtained using one-colour and two-colour resonance-enhanced multiphoton ionisation spectroscopy. Estimates of the dissociation energies of both complexes are given. The appearance of spectra in both the Kr·NO+ and Kr+ mass channels was investigated, and mechanisms for the formation of Kr+ ions are discussed. Spectra of the à state of the Ar·NO complex are also presented. The non-Rydberg behaviour of the à states of Ar·NO and Kr·NO is discussed.

Constant ionic state spectra of carbon monosulphide are presented in the photon energy range 11.3 - 20 electron volts using synchrotron radiation. The spectra, recorded using several vibrational components of the ground ionic state of CS have been assigned using quantum defect analysis.

In Chapter 4, results obtained by scattering laser and synchrotron radiation off pulsed free jet expansions of Ar and N2O are presented. The results are interpreted in terms of Rayleigh scattering from clusters formed within the free jet. Information on the relative size of clusters formed is obtained and compared to literature data. Where synchrotron radiation was used, contributions from non-Rayleigh scattering processes are considered.

ab initio molecular orbital calculations on the NO2+·X (X=H2O, N2, CO2) series of complexes are reported in Chapter 5. Optimised geometries and vibrational frequencies, as well as computed total energies have been used to calculate standard enthalpies, entropies and free energies for the complexing and ligand-switching reactions between the three molecular complexes. The results obtained have been compared to previous experimental and theoretical values where available.

The intermolecular potential energy surface of the Ar·NO+ cationic complex has been calculated using ab initio molecular orbital calculations. The effect of level of theory, basis set, NO+ bond length and basis set superposition error was investigated. The calculated surfaces were used to obtain intermolecular vibrational frequencies, which were compared to previous calculations and experimental results.

This record has no associated files available for download.

More information

Published date: 1997

Identifiers

Local EPrints ID: 460264
URI: http://eprints.soton.ac.uk/id/eprint/460264
PURE UUID: fcb3a3db-6d67-4aef-8389-79941e555891

Catalogue record

Date deposited: 04 Jul 2022 18:17
Last modified: 04 Jul 2022 18:17

Export record

Contributors

Author: Andrew Marcus Bush

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×