Page 10 - PERIODIC Magazine Issue 6

insoluble fluoride salt into solution, modulates the reactivity of References:
the fluoride via hydrogen bonding and selectively directs its
attack towards one carbon on a target molecule. (1) Jones, J.A.; Jaksh, D.; Quantum
Information, Computation and
Thus, it is hoped that this methodology will give access to a Communication, Cambridge University
range of previously inaccessible fluorine compounds,while
opening the door to numerous novel transformations Press, 2012.
involving other inorganic salts which have not been used so (2) Slota, M.; Keerthi, A.; Myers, W.K.;
far in organic chemistry because of their insolubility. Tretyakov, E.; Baumgarten, M.; Ardavan,
A.; Sadeghi, H.; Lambert, C.J.; Narita,
A.; Müllen, K.; Bogani, L.; Magnetic
edge states and coherent manipulation
William Myers (Centre for Advanced of graphene nanoribbons, Nature 2018,
Electron Spin Resonance CÆSR) 557, 691–695, (doi: 10.1038/s41586-
Spin-injected graphene nanoribbons 018-0154-7).018-0154-7).

Recent studies by Dr William
Myers have considered the
properties of graphene, a
two-dimensional network Figure below: Nitronyl nitroxide-
2
of sp -hybridised (planar) graphene nanoribbons and their band
carbon atoms that promises to structure, showing localized states and
revolutionise a wide range of
technologies. spin injection inside delocalized edge
state. Energy levels are shown versus the
The use of electron wavevector k times the repeating unit
spin resonance (ESR) at 9.4, 34, and 94 GHz allows
characterisation of the paramagnetic ground states (i.e. those length l. Molecular orbitals calculated
possessing unpaired electrons) that can be created along for different energy ranges are depicted
the edges of narrow graphene strips, known as graphene (azure and orange shaded areas and
nanoribbons. The work, published in Nature, was performed arrows), with blue and red referring to
in collaboration with the Bogani and Ardavan groups, of the spin up and down states, respectively.
Departments of Materials and Physics, respectively.

The introduction of stable nitroxide groups at the right interval
along the edge of a graphene nanoribbon gives the product
a range of interesting properties. This is because the unpaired
electrons are delocalized from the NO groups into the
graphene nanoribbon’s π-orbitals. One exciting application
of this new material is in quantum computing, where the
graphene nanoribbon can act as what is known as a qubit,
or quantum bit. Unlike classical bits, which possess discrete
states of 0 and 1, qubits give rise to a larger number of states,
which would enhance the processing capabilities of
a computer.
Graphene nanoribbons do not have the same low
temperature requirement as other quantum computers, which
is what makes them such an exciting prospect. In the future,
Dr Myers hopes to continue work on the properties of the
graphene nanoribbons to produce different systems, such
as placing other spin-bearing species into defects within and
along the edge of the ribbon.

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Periodic The Magazine of the Department of Chemistry