Developing light-driven molecular switches for use on solid substrates

Designing purpose built molecular devices is one of the ultimate goals of nanotechnology, potentially permitting mechanical control at the sub-nanometer scale. One of the primary fields in such work is the design of light-driven molecular switches and motors, which alter their conformation after exposure to specific frequencies of light. Many molecules have been designed that can perform light-driven switching when in a solvent, however these capabilities are almost always quenched when such molecules are dispersed onto a solid surface.

This PhD project aims to exploit a chemically flexible group of switching molecules, hemithioindigos (HTIs), which can be tailored with a wide variety of different functional groups, to understand what is required to design a molecule that will maintain its switching capabilities on a solid substrate. This will be done by a feedback loop between high precision measurements, that allow us to quantitatively probe the structure of these molecules down to a few thousandths of a nanometer and state-of-the-art theoretical calculations. Theoretical density functional theory calculations will be used to predict how different functionalisations of the molecules will affect their switching capabilities when supported on a substrate, and the experimental X-ray standing waves measurements will then probe these capabilities by monitoring differences in the adsorbed structure, feeding back stringent benchmark parameters to refine the calculations to facilitate more accurate predictions.

During this joint PhD project between Diamond Light Source and the University of Warwick, the student will learn how to exploit cutting edge research tools at large central facilities in tandem with learning how to perform cutting edge density functional theory calculations. The student will also be involved in developing new tools for data analyses, exploiting recent advances in machine learning.

Should this work be successful it would constitute a leap forward in such nano-machines, potentially allowing future molecular switches and motors to be rationally designed, rather than relying upon trial-and-error methodologies.

This project is suitable for students with a background in the physical sciences (physics, chemistry, materials science) and the successful applicants will have a minimum of a 2:1 first degree in a relevant discipline/subject area.