Page 7 - Periodic Issue 04

One ongoing project is a collaboration with Henrik compatible with the warm, wet and noisy environment of a
Mouritsen, a biologist at the University of Oldenburg magnetoreceptor cell.
in Germany. When tested on the university campus in
Oldenburg, migratory European robins are incapable of It would be nice to get to the bottom of this least
using their magnetic compass unless they are efficiently understood of sensory mechanisms, and better still if
shielded from the very weak electromagnetic fields practical applications emerged along the way. In the last few
(“electrosmog”) generated by electrical equipment in the years it has been found that semiconductors constructed
nearby laboratories. In the countryside, a few miles outside entirely from non-magnetic organic materials exhibit room-
the city, the same birds orient perfectly well. Even though temperature changes in their current and light output that
it is clear that radical pair chemistry can be influenced can be tuned by weak, externally applied magnetic fields.
by time-dependent magnetic fields, it is astonishing that The spin physics behind these effects is essentially identical
such weak electromagnetic noise — at a level below the to the radical pair mechanism, with polarons playing the
World Health Organization’s recommendations for safe role of the radicals. With “bio-inspiration” gleaned from
human exposure — could disrupt the behaviour of a studies of the bird-compass it may be possible to make
higher vertebrate. The challenge is now to determine the cheap, electronically addressable magnetic sensors from
origin of the effect using a combination of behavioural non-toxic organic materials. As a first step in this direction,
studies, laboratory experiments on cryptochromes, and the Manolopoulos group has recently made considerable
computational modelling. We hope that electrosmog inroads into understanding the detailed relation between
disorientation will provide powerful insights into the inner magnetoelectroluminescence and magnetoconductance in
working of the compass sense. organic light emitting diodes.

Other work is supported by the Air Force Office of One thing that comes out of all of this is that the
Scientific Research which is concerned about the American disparaging term “bird brain” should more correctly
military’s over-reliance on global positioning systems. be regarded as a compliment. Birds may not have a
In one project, we have shown that the radical form of SatNav capability but they could well “know” a bit more
the flavin chromophore in cryptochrome has magnetic chemistry (and quantum mechanics) than anyone realized:
interactions that could result in the protein being a much ChemNav, perhaps?
better compass than previously thought. The hyperfine
interactions in the flavin radical are such that the quantum * See Hore and Mouritsen, Annu. Rev. Biophys. 45 (2016) 299–344,
oscillations of the spin-coherence can be exquisitely in which we attempt to explain the physics and chemistry of radical
sensitive to the direction of the geomagnetic field. All pair magnetoreception to biologists and the biology and chemistry
to physicists. k T , Boltzmann’s constant multiplied by temperature,
B
we have to do now is to establish whether the conditions is the the energy associated with the ever-present random motions of
necessary for the realisation of this “quantum needle” are molecules as they bump into one another, rotate, and vibrate.

Launch of ChemBioPlants network

2016 saw the launch of a new network to bring together researchers from the
Departments of Chemistry, Biochemistry and Plant Sciences. ChemBioPlants
aims to foster and support new collaborations at the interface of these disciplines,
providing a forum through which researchers can explore ideas and identify
projects where complementary approaches will be advantageous. By combining
expertise, such interdisciplinary research will be able to help address issues of global
importance such as food security, sustainable agriculture, exploitation of plant
natural products, bioenergy and the relationship between food and health.
Two networking events held so far this year have been very successful, with short talks and poster sessions from across the
departments revealing the breadth of excellent research going on in Oxford as well as highlighting multiple opportunities to work
together. Importantly, the network has been able to provide small grants to kick-start new collaborative projects, all of which are
now under way. Further events will take place on a termly basis, and a website is being developed as a portal to access research
interests across the network, as well as news, funding opportunities and research success stories.

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Periodic
The Magazine of the Department of Chemistry