Dr Sarah Masters
Position
Lecturer
Qualifications
BSc(Hons), PhD(University of Edinburgh)
Field of Study
Structural and Physical Chemistry
Room
636
Contact Details
Telephone: +64 3 364 2456
Fax: +64 3 364 2110
Email: sarah.masters@canterbury.ac.nz
Background
Sarah took a BSc(Hons) in Chemistry at the University of Edinburgh, UK, followed by a PhD with Professor David Rankin, which she completed in 2000. She then undertook a Postdoc in the Rankin group, and managed the UK Gas Electron Diffraction service. She was awarded a Royal Society of Edinburgh / BP Personal Research Fellowship in 2005 to develop new methods for the structure determination of short-lived species. Sarah joined the Chemistry Department at Canterbury as a lecturer in January 2011.
Publications and Research Interests
See Masters Group Research webpages
Chemistry never ceases to amaze, and we are always reading about new technologies and products – materials, medicines, chemicals with special properties. To make their work efficient, chemists need to be able to predict the properties of target molecules, and to understand the routes to these molecules, and the rates at which reactions will take place. Techniques for determining molecular structures are therefore of primary importance.
Nowadays computers can predict structures of many molecules accurately, and they may also model gas-phase reactions. However, the programs use standard information from experimental gaseous structures, so new, accurate information from gas-phase experiments is always required. There is a mass of gaseous structural information for stable molecules, but information about short-lived or unstable species is much harder to obtain. Data are scarce, although they are essential for modelling reaction pathways and thus predicting rates of reactions. My research is geared towards providing this information. Research areas include the structure determination of short-lived species using combined FVP-GED techniques, and the structure determination of stable radicals.
Short-lived species are generated using flash vacuum pyrolysis (FVP) techniques. The methodologies of FVP and GED have been combined in a new inlet system, and the unstable species are passed into the diffraction chamber where structural data is collected. Very-high temperatures are required for this work, as the short-lived species are usually generated at temperatures between 500 and 900 K.
Generating stable radicals from sterically loaded systems is in the very early stages of experimental investigation. The systems Z2R4 / ZR2 [Z = P or As, R = CH(SiMe3)2] provided the first known examples of molecules with relatively normal strong Z-Z bonds, which required no additional energy to break. The driving force for dissociation is the conformational change, which allows relaxation of the steric strain upon dissociation. This led to the term 'jack-in-the-box' molecules being applied to these systems. Other systems have been predicted to behave in this manner, although no experimental work has been carried out on them. Work is currently underway to examine the process of dissociation in other symmetric and also asymmetric systems using experimental and theoretical methods.
Undergraduate Courses
Graduate Courses
CHEM400 level – Module "Gas Phase Structural Methods"