Research

Research in the Woodward Laboratory is highly interdisciplinary, incorporating aspects of physics, chemistry and biology, and employing both experimental and theoretical methods. The main research areas can be divided up as follows:

Instrument Development

One of the key aspects of research in the Woodward group is the application of new experimental approaches to solve scientific problems. Thus almost all the instrumentation in the Woodward group has been developed, designed and built by the group itself. Building new instruments has a great advantage in allowing new measurements to be made, but requires a large amount of work before measurements can be made and a wide range of skills and expertise of the group members.

 

Examples of new instrumentation include instruments to measure the effect of RF radiation on chemical reactions (Woodward, at Oxford), the use of short resonant microwave pulses in ODMR (Woodward, at Riken, Japan), magnetic field effects by time-resolved IR spectroscopy (Leicester), rapid magnetic field switching circuitry and techniques (Leicester), magnetic field effect stopped flow instrumentation for enzyme kinetics (Leicester, Manchester), VUV generation and wavelength separation methods (Woodward, at Tokyo Tech) and the recently developed TOAD and MIM imaging microscope (University of Tokyo).

 

Selected publications

 

"Optical Absorption and Magnetic Field Effect Based Imaging of Transient Radicals", J. P. Beardmore, L M. Antill, and J. R. Woodward, Angew. Chem. Int. Ed. 2015, DOI: 10.1002/anie.201502591.

 

"A two-color tunable infrared/vacuum ultraviolet spectrometer for high-resolution spectroscopy of molecules in molecular beams’, J. R. Woodward, H. Watanabe, S. Ishiuchi and M. Fujii; Rev Sci Instrum. 83 (1), 014102 (2012).

 

"Rapid rise time pulsed magnetic field circuit for pump-probe field effect studies," T. A. Salaoru, and J. R. Woodward.  Rev Sci Instrum., 78(3), 036104. (2007)

Magnetic Field Effects in Chemical Systems

The sensitivity of RP reactions to magnetic fields was established in the 1970s and research in this area has continued unabated since. The dynamics of RPs are fascinating as they involve in time in a way that depends on both the structure of the radicals (primarily in terms of their hyperfine couplings which are responsible for driving quantum mechanical spin-state evolution between the singlet and triplet RP states) and the environment of the pair (which may evolve stochastically as RPs diffuse in solution, or may be more controlled if the positions of the RP members can be anchored). This combination of coherent quantum evolution coupled with stochastic changes in the positions of the pair members represents a fascinating chemical system. 

Our recent work has focussed on understanding the LFE - a kind of field effect observed at very weak magnetic fields, better understanding of the contribution of geminate born and freely diffusing RPs and we are currently interested in RPs in various kinds of microreactor and also in solid-state systems.

 

 

Selected publications

 

"Direct observation of f-pair magnetic field effects and time-dependence of radical pair composition using rapidly switched magnetic fields and time-resolved infrared methods.", T. A. Foster, A. T. Salaoru, C. B. Vink and J. R. Woodward, Phys. Chem. Chem. Phys. 10, 4020 - 4026 (2008).

 

"Hyperfine coupling dependence of the effects of weak magnetic fields on the recombination reactions of radicals generated from polymerisation photoinitiators", J. R. Woodward and C. B. Vink; Phys. Chem. Chem. Phys., 9, 6272-6278 (2007).

 

‘Effect of a Weak Magnetic Field on the Reaction between Neutral Free Radicals in Isotropic Solution’, C. B. Vink and J. R. Woodward, J. Am. Chem. Soc., 126(51) , 16731 (2004).

Magnetic Field Effects in Biological Systems

One of the key research areas of the group is in investigating the magnetosensitivity of biological systems. There are two main perspectives for this interest :

 

1) Studies have shown a non-vanishing correlation between childhood leukaemia and the distance between residence and electric power distribution lines. More generally, if RP reactions are magnetic field sensitive and some biological processes involve RPs, then it is entirely possible that magnetic fields may have a deleterious or beneficial effect on human health.

 

2) Recent work by the spin chemistry community and animal behavioral biologists has begun to strongly suggest that the ability of many different animals to navigate in the earth's magnetic field may be linked to RP based reactions in photoreceptors involving a group of proteins known as the cryptochromes. Our current studies are focussed on investigating field effect in these and related systems within biological cells.

 

 

Selected publications

 

‘Continuous Wave Photolysis Magnetic Field Effect Investigations with Free and Protein-Bound Alkylcobalamins’, Alex R. Jones, Jonathan R. Woodward, and Nigel S. Scrutton; J. Am. Chem. Soc., 131,17246-17253 (2009).

 

‘Magnetic Field Effect Studies Indicate that the Radical Pair in Adenosylcobalamin- Dependent Ethanolamine Ammonia Lyase is Stabilized Against Geminate Recombination’, A. R. Jones, Sam Hay, J. R. Woodward and N. S. Scrutton, J. Am. Chem. Soc., 129, 15718- 1572 (2007)

 

‘Magnetic Field Effects and Radical Pair Mechanisms in Enzymes: A Reappraisal of the Horseradish Peroxidase System’, A. R. Jones, N. S. Scrutton and J. R. Woodward, J. Am. Chem. Soc., 128, 8408 (2006).

Resonant Magnetic Spectroscopies

Prof. Woodward began his scientific research in the group of Prof. Keith McLauchlan at the University of Oxford, one of the pioneers of time-resolved electron paramagnetic resonance and CIDEP (chemically induced dynamic electron polarization). EPR is a very powerful technique for studying radicals, their structure and interactions and their reactivity. When RPs are generated in a suitable photochemical reaction, they are often born in a state where their nuclear spin state distribution is very far from equilibrium. This gives rise to polarized EPR signals that provide unique and powerful information about the origin and reactions of the pair. Combined with the detailed structural information that EPR is known for, such techniques are very important weapons in the armoury of the spin chemist.

 

The Woodward group has used various forms of EPR in a number of different contexts - to study RP dynamics, to elucidate the mechanisms of photochemical processes and to study biologically important radical species.

 

 

 

 

Selected publications

 

"Elucidation of the Mechanism by Which Catecholamine Stress Hormones Liberate Iron from the Innate Immune Defense Proteins Transferrin and Lactoferrin," S. M. Sandrini, R. Shergill, J.R. Woodward, R. Muralikuttan, R. D. Haigh, M. Lyte, and P. P. Freestone,  Journal of Bacteriology, 192(2), 587–594.

 

‘‘Evidence for a novel bisacylphosphine oxide photoreaction from TRIR, TREPR and DFT studies," R. S. Shergill, M. Haberler, C. B. Vink, H. V. Patten and J. R. Woodward, Phys. Chem. Chem. Phys., 11, 7248–7256 (2009).

 

"Alternative source of emissive CIDEP in the TREPR spectra of benzophenone in alcohols," A.R. Jones and J. R. Woodward, Mol. Phys., 104 (10-11), 1551 (2006).