High-Redox Density Molecules and Self-Assembled Molecular Materials

2019 start date flexible, any time before/up to October 2019 entry

Redox-active organic molecules have been a subject of intense research because of their potential to stabilise charge (ideally in the form of multiple radical electrons) and efficiently release the energy stored on demand. Aromatic imides are a class of redox-active organic compounds that are able to undergo reversible electrochemical reduction processes to form radical and anionic states with absorption properties that are attractive energy storage and light-harvesting applications. In the neutral state, close-range overlap of their electron-deficient π-orbitals, i.e., via face-to-face aromatic interactions, can create efficient electronic pathways for charge (i.e., electrons) to be transported through-space across relatively long distances. When these processes are enabled in the solid-state, these types of molecular-level interactions can lead to materials with excellent conductivity properties.

A common challenge in harnessing the full potential of aromatic imides as efficient energy storage and electron transport materials is being able to control the exact nature of their π-electronic surface interactions, both in solution and in the solid-state (i.e., for applications.) In the Avestro Group, we are taking advantage of non-covalent (e.g., hydrogen-, halogen-) bonding interactions, rigid covalent bond geometries and even metal coordination to direct the alignment, facial orientation, and degree of π-orbital overlap of aromatic imides. This project will probe the subtle effects of region- and stereochemistry of non-covalent directing groups, molecular symmetry and bond geometry (i.e., conferred by covalent bonds and coordinating metals) on electron transport, electrochemical stability and, where applicable, molecular recognition properties. In this vein, the Avestro Group is also interested in preparing discotic aromatic imides with multiple redox-active sites to enhance π-surface interactions and boost the molar charge storage capacity of these materials. Finally, when such high charge capacity aromatic imides are constructed into 3D prismatic/tubular structures, the radial conjugation of their π-orbitals is expected to enhance both electrochemical stability and the transport of charged species through well-defined nanosized channels of the molecules.

the PhD candidate joining the Avestro Molecular Materials for Energy research group will pursue the organic synthesis, assembly and materials characterisation of various electroactive aromatic imides containing a high density of redox-active centres and N-functional groups to direct the co-facial interactions of their π-surfaces into 1-, 2- and 3D structures. They will employ a wide range of techniques and spectroscopies, electrochemistry, imaging microscopy and diffraction analyses to determine structure–property correlations in solutions, gels, and solid-state single crystals. There will be opportunities for the student to work collaboratively alongside senior PDRAs and talented undergraduate project students working on parallel areas of research involving aromatic imides in the Avestro Group.

This project is supported by the Royal Society, the Global Challenges Research Fund and the Department of Chemistry at York. For more information on this project and other opportunities, please visit the Avestro Group on Twitter at @ajavestro and:
https://www.york.ac.uk/chemistry/staff/academic/a-c/dr-avestro

All students follow our Innovative Doctoral Training in Chemistry programme: https://www.york.ac.uk/chemistry/postgraduate/idtc/

The Department strives to provide a working environment which allows all staff and students to contribute fully, to flourish, and to excel: https://www.york.ac.uk/chemistry/ed/

The final year of this four year studentship will be funded by a Chemistry Teaching Studentship:
https://www.york.ac.uk/chemistry/postgraduate/research/industry-teachingphd/

This PhD will formally start on 1 October 2019. Induction activities will start on 30 September.