School of Chemistry

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Ben Whitaker

Professor of Chemical Physics
Member of the Computational Chemistry and Chemical Physics group

Contact details

Room: 2.87
Tel: +44 (0)113 3436580
Email: B.J.Whitaker@leeds.ac.uk

Keywords

Molecular Reaction Dynamics
Velocity Map and DC Slice Imaging
Quantum Coherent Control and Ultrafast Laser Spectroscopy
Time-Resolved Photoelectron Spectroscopy


Photograph of Ben Whitaker

Research interests

The main focus of our research is the study of elementary reaction mechanism at the quantum resolved level (molecular reaction dynamics). We use, and have developed, a number of experimental techniques in both the frequency and time domain; particularly through the application of velocity map imaging (VMI). In the frequency domain, we use nanosecond lasers to study photofragment product state distributions through a combination of spectroscopy, e.g. resonant multiphoton ionization (REMPI), and ion imaging. In the time domain, we use pump-probe techniques with femtosecond lasers and photoelectron/photoion imaging to study internal energy conversion in molecules. As an example of the applications of this work, we are currently funded by the EPSRC to apply VMI to measure the bond dissociation energy of HO3. This species has recently been proposed to act as a sink for OH radicals in the stratosphere, but this can only be true if the dissociation energy is significantly greater than 10 kJ mol-1, and current theory and experiment disagree (by a factor of 2) over the value.

As we begin to understand more about the details of fundamental chemical processes we begin to understand how we might control them at the quantum level. We are working with acousto-optical programmable dispersive filters (AOPDFs) to modulate the spectral phase and amplitude of ultrashort pulses of light so as to implement coherent control schemes for chemical reactivity. We use genetic algorithms and other evolutionary computational methods to "teach" the modulator how to acheive a particular chemical outcome with a shaped pulse of light. This in turn leads us to an interest in other applications of evolutionary computing, particularly in nanoscience and molecular electronics.

Our research group is a member of the ICONIC Marie Curie Initial Training Network funded by the European Union. ICONIC is an acronym for Imaging and CONtrol In Chemistry and the network aims to provide scientific training of young researchers through collaboration and exchange between 11 academic and 4 industrial partners.

Useful links

Bibliography   
Research Opportunities   
PICNIC   
EPSRC grant report

Selected publications

BJ Whitaker (ed.), 'Imaging in Molecular Dynamics', Cambridge University Press, 2003

M Tsubouchi, BJ Whitaker, L Wang, H Kohguchi and T Suzuki, 'Photoelectron Imaging on Time-Dependent Molecular Alignment Created by a Femtosecond Laser Pulse', Phys. Rev. Lett., 86 (2001) 45004503.

I Wilkinson and BJ Whitaker,'Photodissociation of NO2 in the (2)2B2 state: A slice imaging study and reinterpretation of previous results', J. Chem. Phys, 129 (2008) 154312.

NT Form, BJ Whitaker and C Meier, 'Enhancing the probability of three-photon absorption in iodine through pulse shaping', J. Phys. B: At., Mol. and Opt. Phys., 41 (2008) o74011.