Ultraviolet photofragmentation spectroscopy of metal dication sandwich complexes in the gas phase combined with DFT/TDDFT calculations

Metal dication-ligand sandwich complexes have attracted intense attention recently for their widely use in catalysis, biochemistry and material science. The experimental techniques developed by our group have allowed forming, confining, cooling and investigating a wide range of metal dication comple...

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Main Author:	Ma, Lifu
Format:	Thesis (University of Nottingham only)
Language:	English
Published:	2013
Online Access:	http://eprints.nottingham.ac.uk/13578/ http://eprints.nottingham.ac.uk/13578/1/thesis_print.pdf

id	nottingham-13578
recordtype	eprints
spelling	nottingham-135782017-12-15T09:50:39Z http://eprints.nottingham.ac.uk/13578/ Ultraviolet photofragmentation spectroscopy of metal dication sandwich complexes in the gas phase combined with DFT/TDDFT calculations Ma, Lifu Metal dication-ligand sandwich complexes have attracted intense attention recently for their widely use in catalysis, biochemistry and material science. The experimental techniques developed by our group have allowed forming, confining, cooling and investigating a wide range of metal dication complexes in the gas phase. In this thesis, the ultraviolet photofragmentation studies of Pb(II), Cu(II) and Ca(II) sandwich complexes with aromatic ligands are performed using a hybrid quadrupole ion trap instrument, followed by DFT/TDDFT calculations. The experimental results indicate that the complexes are capable of yielding structured, sometimes conformation resolved, UV spectra. The spectra of metal dication-benzene complexes exhibit features in the wavelength range 220-270 nm and a big raise as the wavelength decreases. The lead dication-bis(toluene) complex spectrum shows some well-resolved features arising from different conformers. The theory suggests that all of these complexes have excitations including significant contributions from the metal-based orbital. The adiabatic TDDFT methodology is able to give reasonable agreement between the calculated excitations and the experimental spectra for the close-shell complexes. But for some open-shell complexes, the calculated excitations are spin contaminated, which need to be discarded or corrected in the future. The degree of spin contamination for selected excitations is qualified by calculating the <S2> values. For lead and calcium open-shell complexes, most of the excitations that can match the experimental features can be trusted. However, for the copper open-shell complex, only three states are ~90% doublet in their character which are responsible for some excitations that can match the spectra. Challenges such as developing the theory to describe the open-shell system and refining the experimental techniques to improve the resolution of the spectra, still remain. 2013-12-10 Thesis (University of Nottingham only) NonPeerReviewed application/pdf en http://eprints.nottingham.ac.uk/13578/1/thesis_print.pdf Ma, Lifu (2013) Ultraviolet photofragmentation spectroscopy of metal dication sandwich complexes in the gas phase combined with DFT/TDDFT calculations. PhD thesis, University of Nottingham.
repository_type	Digital Repository
institution_category	Local University
institution	University of Nottingham Malaysia Campus
building	Nottingham Research Data Repository
collection	Online Access
language	English
description	Metal dication-ligand sandwich complexes have attracted intense attention recently for their widely use in catalysis, biochemistry and material science. The experimental techniques developed by our group have allowed forming, confining, cooling and investigating a wide range of metal dication complexes in the gas phase. In this thesis, the ultraviolet photofragmentation studies of Pb(II), Cu(II) and Ca(II) sandwich complexes with aromatic ligands are performed using a hybrid quadrupole ion trap instrument, followed by DFT/TDDFT calculations. The experimental results indicate that the complexes are capable of yielding structured, sometimes conformation resolved, UV spectra. The spectra of metal dication-benzene complexes exhibit features in the wavelength range 220-270 nm and a big raise as the wavelength decreases. The lead dication-bis(toluene) complex spectrum shows some well-resolved features arising from different conformers. The theory suggests that all of these complexes have excitations including significant contributions from the metal-based orbital. The adiabatic TDDFT methodology is able to give reasonable agreement between the calculated excitations and the experimental spectra for the close-shell complexes. But for some open-shell complexes, the calculated excitations are spin contaminated, which need to be discarded or corrected in the future. The degree of spin contamination for selected excitations is qualified by calculating the <S2> values. For lead and calcium open-shell complexes, most of the excitations that can match the experimental features can be trusted. However, for the copper open-shell complex, only three states are ~90% doublet in their character which are responsible for some excitations that can match the spectra. Challenges such as developing the theory to describe the open-shell system and refining the experimental techniques to improve the resolution of the spectra, still remain.
format	Thesis (University of Nottingham only)
author	Ma, Lifu
spellingShingle	Ma, Lifu Ultraviolet photofragmentation spectroscopy of metal dication sandwich complexes in the gas phase combined with DFT/TDDFT calculations
author_facet	Ma, Lifu
author_sort	Ma, Lifu
title	Ultraviolet photofragmentation spectroscopy of metal dication sandwich complexes in the gas phase combined with DFT/TDDFT calculations
title_short	Ultraviolet photofragmentation spectroscopy of metal dication sandwich complexes in the gas phase combined with DFT/TDDFT calculations
title_full	Ultraviolet photofragmentation spectroscopy of metal dication sandwich complexes in the gas phase combined with DFT/TDDFT calculations
title_fullStr	Ultraviolet photofragmentation spectroscopy of metal dication sandwich complexes in the gas phase combined with DFT/TDDFT calculations
title_full_unstemmed	Ultraviolet photofragmentation spectroscopy of metal dication sandwich complexes in the gas phase combined with DFT/TDDFT calculations
title_sort	ultraviolet photofragmentation spectroscopy of metal dication sandwich complexes in the gas phase combined with dft/tddft calculations
publishDate	2013
url	http://eprints.nottingham.ac.uk/13578/ http://eprints.nottingham.ac.uk/13578/1/thesis_print.pdf
first_indexed	2018-09-06T10:53:56Z
last_indexed	2018-09-06T10:53:56Z
_version_	1610855204678270976

Ultraviolet photofragmentation spectroscopy of metal dication sandwich complexes in the gas phase combined with DFT/TDDFT calculations

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