Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.490585
Title: Spectroelectrochemistry and Ultrafast Polarisation Spectroscopy of Buckminsterfullerene Anions
Author: Hope, Michael John
Awarding Body: University of East Anglia
Current Institution: University of East Anglia
Date of Award: 2008
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Abstract:
A spectroelectrochemical cell for the synthesis and in situ spectroscopic analysis of oxygen-reactive Buckminsterfullerene anions was designed and constructed. This cell enabled the first two anions of Buckminsterfullerene to be prepared and stabilised for steady state and ultrafast spectroscopy. A third anion was obtainable and was similiarly prepared although it was less stable. Each of these anions has a characteristic absorption spectrum with features towards the red of the visible spectrum and into the near-infrared. In order to observe these spectra it was necessary to obtain and calibrate a spectrometer with a response in the 800 to 1100 nm region. Spectra were separated for each anion, given assignments and correlated with electrochemical measurements. Spectroelectrochemical studies on the monoanion lead to a new assignment of its vibronic structure arising from a dynamic Jahn-Teller effect. A fluorescence spectrum of the trianion was recorded for the first time, and fluorescence data for the monoanion were observed with higher resolution than has been previously reported. Analysis of the monoanion fluorescence data and solvent effects has revealed further structure which suggests that the vibronic coupling is more complex than initially thought. Laser spectroscopy using a home built ultrafast cavity dumped nearinfrared laser probed the population and orientati~nal relaxation ofthe mono and dianions. Our aim was to investigate possible pseudorotation in the monoanion, arising from a dynamic Jahn-Teller effect. Preliminary data measured suggest a reorientation between 2 and 5 ps. This relaxation' is faster than expected for molecular rotations, suggesting that we might be observing pseudorotation. This warrants further investigation by temperature and viscosity dependent studies.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.490585  DOI: Not available
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