Study level
PhD
Master of Philosophy
Honours
Vacation research experience scheme
Background
Developing “light controllable product selectivity switches” is of great interest in cross-coupling reactions based chemical synthesis. Nanoparticles of plasmonic metals can intensely absorb visible light due to the localized surface plasmon resonance (LSPR) effect, the conduction electrons gain the energy of the incident light through LSPR effect. Furthermore, the oscillating electric dipole generates intense electromagnetic field in close proximity to the NP. The application of photo-excited energetic electrons in direct photocatalysis of metal NPs is well established by our previous studies. However, the plasmonic field enhancement property has not yet been widely used in important chemical synthesis due to the challenge of designing a feasible catalyst-reaction system directly applying the field enhancement.
On an environmentally friendly plasmonic metal nanoparticle surface, light irradiation can change the reactants adsorption on the surface, and thus change the relative ratio of the reactants for reaction. This adsorption selectivity change is due to the enhanced electromagnetic field of the plasmonic metal, and thus change the reacting ratio of the reactants to give different product. Different wavelengths contribute to tune this selectivity more accurately in a molecular level. We were only able to observe this phenomenon from the concentration change of bulk solution in our previous study, but not able to see directly from the surface. Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) is a surface-sensitive analytical method that uses a pulsed ion beam to identify molecules from the very outermost surface of the sample, which will be a helpful characterisation tool to visualizing the adsorption process.
In this project, we aim to develop a one pot synthesis of macrocycles using the wavelength to tune Sonogashira or Glaser coupling, with controllable cyclisation selectivity under diluted conditions.
Research Activities
In this project, we plan to investigate a novel method to synthesis macrocycle molecules using plasmonic catalysis. The basic reactions of Sonogashira and Glaser coupling to form different C-C bonds, can be tuned by wavelengths, and thus the cyclisation selectivity can be tuned by wavelengths. The wavelength dependent adsorption of molecules on plasmonic metal nanoparticle surface by visualizing the process based on ToF-SIMS technique.
Outcomes
Develop a new method of macrocycles synthesis technology by light and plasmonic electromagnetic field, with high selectivity and efficiency.
Skills and experience
Upon successful completion of this project, students will:
• Have the basic skills necessary to acquire, process, report and interpret research experimental data from a number of techniques, including sample preparation and analysis by ToF-SIMS, SEM-EDS, XRF, FTIR and organic compound analysis.
• Have an overview of practical approaches to the study of materials in relation to wider research questions.
• Be able to debate the role of science-based studies in physical and organic chemistry, including the potential advantages and constraints inherent within different approaches.
• Have the ability to critically assess reports and publications deriving from research project, as well as to propose analytical projects with physical chemistry relevance.
