Trinity College Dublin

Research

SNIAMS Building, Main Campus, Trinity College Dublin

Triplet Sensitisers

Molecular Switches

As the drive for the miniaturisation of computational devices increases, so too does the demand for efficient memory storage on the microscopic scale. The limiting situation to which we aspire is the reading and writing of data on the molecular level. Taking note of the promise held by dithienylethene-type switches, we are currently developing a family of such compounds with the hope of increasing switching efficiency and improving reading methods – from absorption detection methods to emission and emission lifetime outputs.

Innovative Planarised Systems

For the last decade molecular graphenes have formed the cornerstone of the research activities carried out in the Draper group. The work has pioneered the inclusion of heteroatoms into the periphery of the systems so as to confer on them an additional range of useful properties, beyond their thermal stability, such as increased solubility and intense charge-transfer derived emission. Their luminescence can readily be “tuned” by modifying factors such as solvent polarity, acidity and the presence of exogenous ions and chemically via substituent effects.

Photocatalytic Hydrogen Generation

Work has begun on the design of novel bridging ligands for the photocatalytic generation of hydrogen from water. The design, synthesis, and photophysical properties of these new catalytic systems are being investigated with promising results.  Work has already begun on hydrogen generation tests and future work will include optimisation of the catalytic system design, TON optimisation and device feasibility studies.

In collaboration with our Chinese collaborators in Dalian University of Technology, we have begun investigating our systems’ potential as a new family of compounds that can act as donors in triplet-triplet annihilation (TTA) upconversion applications. At a basic level, TTA upconversion involves the excitation of a high-energy excited state in an acceptor molecule via the low-energy excitation of a donor molecule. This phenomenon is a relatively new avenue of research and has exciting prospects for future solar energy applications – e.g. the upconversion of low-energy radiation from the sun to give high energy photons.

Novel Complexes

While our work encompasses advanced organic synthesis and specialised physical measurements, we are predominately an inorganic group. The inclusion of heteroatoms into graphitic fragments has optical and electronic consequences which we are exploring, but it also allows us to use these systems as very unique ligands. The resulting low-lying LUMO levels in their complexes give rise to extensive absorption deep into the visible range

Terpyridines - New Designs and SAMS

The terpyridine moiety (tpy) is ubiquitous in coordination chemistry – however we have taken its chemistry a step further in both our electrochemical and derivatisation work. For application in self-assembling monolayers (SAMs), we have exploited robust piperazine-derived tethers for attachment of bis-terpyridine Os(II) and Ru(II) complexes to gold electrodes. This results in a favourable decrease in oxidation potential and provides excellent reversible redox behaviour and exceptional stability. We have also successfully endeavoured to increase the size of the tpy platform using cyclodehydrogenation methods, and plan to further exploit these systems using surface techniques.

Currently under investigation are alternative routes to functionalising these systems, their reactivity in solution and on metal surfaces and the development of their use as liquid crystals or as pendant groups for electroactive species.

and emission in the low energy UV/near-IR region. The extensive π-π interactions of the planar regions also result in the formation of varied supramolecular architectures. Outside of typical coordination chemistry, we synthesise novel organometallic π complexes and fascinating platinum acetylides incorporating our large-surface, planarised ligands.