Browse DORAS
Browse Theses
Search
Latest Additions
Creative Commons License
Except where otherwise noted, content on this site is licensed for use under a:

Surface studies and density functional theory analysis of ruthenium polypyridyl complexes

O'Boyle, Noel M. (2004) Surface studies and density functional theory analysis of ruthenium polypyridyl complexes. PhD thesis, Dublin City University.

Full text available as:

[img]
Preview
PDF - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
11Mb

Abstract

In recent years, the computational method Density Functional Theory (DFT) has become more and more important as an effective tool for studying inorganic complexes. This thesis describes computational studies on ruthenium polypyridyltype complexes using DFT. An introduction to the theory behind DFT is presented in the first chapter, as well as a review of previous DFT studies on ruthenium polypyridyl-type complexes. The second chapter describes the details of the computational studies. This includes a description of the basis set, functional, and integration grid. This chapter also describes two pieces of in-house software: GaussSum written to process the output of the computational package Gaussian, and GauStock, which is used to calculate Hirshfeld atomic charges. Chapter 3 examines the electronic structure of a series of complexes related to [Ru(bpy)2(pytrz)]+. The calculated electronic structure is compared with results from experiment. Partial density of states (PDOS) spectra are used to visualise the results. Linkage isomerism and methylation reactions are examined using thermodynamics and, in the case of methylation reactions, also with kinetics. Chapter 4 compares the electronic structure of dinuclear complexes with their corresponding mononuclear analogues. PDOS spectra are used to highlight the changes that occur on addition of a second metal centre. The quality of the predicted Raman frequencies of [Ru(bpy)3]2+ is the focus of Chapter 5. The effect of basis set size, grid size and the inclusion of solvent effects is discussed. The results are compared with the experimental values. Chapter 6 presents the first DFT study of an osmium complex attached to a surface, in this case, to a gold (111) surface. A cluster model is used for the surface. The effect of adsorption on the energy levels of the complex is studied. The effect of oxidation on the adsorbate-substrate bond is also examined. Chapter 7 is an overview of the information available from DFT calculations. DFT is a very useful tool for examining the electronic structure of ruthenium polypyridyl complexes. PDOS spectra highlight changes in electronic structure between related complexes. Trends in oxidation potential are reproduced by the position of the metal PDOS peak. Predicted Raman frequencies agree well with experiment, although a scaling factor is required. Adsorption of an osmium complex on a gold surface causes molecular orbitals close to the surface to shift, while the relative positions of other molecular orbitals remain unchanged. The oxidised complex binds more strongly, due to the change in the nature of the frontier orbitals.

Item Type:Thesis (PhD)
Date of Award:2004
Refereed:No
Supervisor(s):Vos, Johannes G.
Uncontrolled Keywords:Metal complexes; Analysis; Density functionals
Subjects:Physical Sciences > Chemistry
DCU Faculties and Centres:DCU Faculties and Schools > Faculty of Science and Health > School of Chemical Sciences
Use License:This item is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 3.0 License. View License
ID Code:18115
Deposited On:10 May 2013 10:53 by Celine Campbell. Last Modified 21 Jun 2013 11:15

Download statistics

Archive Staff Only: edit this record