Metal complexes of radical ligands

Supervisor(s)

Contact Professor Malcolm Halcrow to discuss this project further informally.

Project description

Metal Complexes of Radical Ligands – Electron Hopping Leading to Novel Optical Properties

This project involves the synthesis, electrochemistry and host:guest chemistry of metal complexes of redox-active (“non-innocent”) ligands.

We are investigating metal complexes containing multiple redox-active organic ligand centres, with a view to producing a new class of mixed-valent molecules and materials. An example is cyclotricatechylene, a cyclic molecule containing three covalently linked catecholate groups that can each bind a metal ion. The platinum complex in the Figure exhibits three reversible low-potential oxidations in its cyclic voltammogram, corresponding to step-wise oxidation of its three catecholate groups to semiquinone radical centres:

The radical oxidation products have intense colours, with strong absorptions in the visible and near-IR regions. This reflects the hopping of unpaired electrons around the macrocycle, between aromatic rings.Near-IR absorbers like these, whose absorptions can be switched on and off electronically, can be very useful in fibre-optic communications devices.

Current work aims to add more steric protection to these ligand radicals, to improve their stability at room temperature; to incorporate these radicals into extended framework (“MOF”) structures with similar electron-hopping properties; and, to design new ligands with different numbers and topologies of redox centres. This project involves organic and inorganic synthesis, crystallography, electrochemistry and other techniques for studying radical products (EPR, UV/vis/NIR and IR spectroscopies, magnetic measurements and DF calculations). 

Entry requirements

Applications are invited from candidates with or expecting a minimum of a UK upper second class honours degree (2:1), and/or a Master's degree in a relevant subject.

If English is not your first language, you must provide evidence that you meet the University’s minimum English Language requirements.

How to apply

Formal applications for research degree study should be made online through the university's website. Please state clearly in the research information section that the PhD you wish to be considered for is the 'Metal Complexes of Radical Ligands – Electron Hopping Leading to Novel Optical Properties’ as well as Professor Malcolm Halcrow as your proposed supervisor.

We welcome scholarship applications from all suitably-qualified candidates, but UK black and minority ethnic (BME) researchers are currently under-represented in our Postgraduate Research community, and we would therefore particularly encourage applications from UK BME candidates.  All scholarships will be awarded on the basis of merit.

If you require any further information please contact the Graduate School Office: maps.pgr.admissions@leeds.ac.uk