Shape shifting molecules: using light to control and explore molecular structure and function

This research is comprised of two distinct, but related projects. The Hebrew University of Jerusalem is the home institution for one project and the University of Melbourne will host the second. The collaboration will ensure the successful completion of the research goals. On application, candidates will specify which home institution they wish to apply for.

The University of Melbourne-based project: Probing the structure and function of carbon clusters

The Melbourne-based project is concerned with experimentally exploring the structural and optical properties of charged carbon clusters containing between 10 and 100 atoms. Carbon clusters in this size range usually have several coexisting structural isomers (chains, rings, bi-rings, fullerenes) that are predicted to possess radically different electronic properties and reactivity.

This structural complexity for pure and doped carbon clusters presents significant opportunities in the realm of material science, but also experimental challenges for measuring and interpreting electronic and infrared spectra.

The PhD candidate will generate carbon clusters that are selected according to size and shape and measure their spectra using unique instrumentation developed by Bieske and his group, supported by substantial Australian Research Council funding.

The ensuing spectroscopic information will help identify new classes of carbon-bearing clusters with potential applications in solar cells and semiconductors and is essential for assessing the presence of carbon clusters in interstellar and circumstellar regions of space.

Understanding the electronic spectra and excited-state dynamics of the target carbon clusters is challenging from a theoretical perspective and requires sophisticated electronic structure calculations that will be conducted by the PhD candidate in collaboration with the Schapiro group.

Project goals:

• Generate new carbon clusters and measure their electronic and vibrational spectra.
• Identify new classes of carbon-bearing clusters with potential applications in solar cells and semiconductors.
• Investigate the electronic absorptions of carbon clusters and compare them to astronomical data to determine. whether carbon clusters exist in the interstellar medium.

The Hebrew University of Jerusalem-based project: Theoretical studies of carbon clusters

The Jerusalem portion of the project will focus on performing quantum chemical calculations to help validate experimental observations. The PhD candidate will begin by studying the same carbon structures determined as being important by the Bieske group.

Studying carbon clusters is challenging due to a large number of isomers possible as the number of carbon atoms is increased. For example, the cluster of 10 carbon atoms can have over 29 minimum structures. The PhD candidate will begin by minimising relevant structures using highly accurate simulations to determine their relative energies.

After optimisation, the PhD candidate will then begin to study the electronic structure properties of each isomer. These include the excitation energies of each isomer, as well as each isomer’s vibrational frequencies and chemical reactivity. The excited state energetics will be obtained through multiple methodologies, such as time-dependent density functional theory and coupled-cluster calculations. These excitation energies can be converted into absorption spectra for comparison to the results obtained in the Bieske group.

Likewise, the vibrational frequencies of each isomer can be determined theoretically through normal mode analysis on the minimized carbon structures. The vibrational frequencies can then be broadened for comparison to experimental IR measurements.

Lastly, the chemical reactivity of the various structures can be studied by modelling the gas-phase dynamics of the various carbon structures in conditions mimicking the interstellar medium.

Project goals:

• Optimise carbon structures using simulations to determine their relative energies
• Study the electronic structures and the physical properties of different carbon cluster isomers
• Study chemical reactivity of the various structures by modelling the gas-phase dynamics

Supervision team

Professor Evan Bieske – The University of Melbourne

Professor Dr Igor Schapiro – The Hebrew University of Jerusalem

Who we are looking for

Skills and requirements:

• Demonstrated experience in the fields of gas-phase molecular spectroscopy, mass spectrometry and computational chemistry.
• Demonstrated ability to work independently and as part of the team.
• Demonstrated time and project management skills.
• Demonstrated ability to write research reports or other publications to a publishable standard (even if not published to date).

Further details

The PhD candidates will benefit from the combined expertise of the project supervisors, and the embedding into two research environments.

Professor Evan Bieske at the University of Melbourne will contribute expertise in the experimental spectroscopic characterization of carbon clusters. Professor Dr Igor Schapiro at the Hebrew University of Jerusalem will contribute expertise in the theoretical understanding of the electronic structure and dynamics of carbon clusters.

The candidates will be enrolled in the PhD program at the Department of Chemistry at the University of Melbourne and in the PhD program in the Institute of Chemistry at the Hebrew University of Jerusalem.

To apply for this joint PhD opportunity, and to view the entry requirements, visit How to apply.