Femtosecond vibrational spectroscopy of liquids, solutions, and biomolecules
Lead Research Organisation:
University of Glasgow
Department Name: School of Chemistry
Abstract
The PhD project involves a technique called femtosecond optical Kerr-effect (OKE) spectroscopy, which measures molecular dynamics on a timescale from femtoseconds to nanoseconds. Fourier transformation of the signal results in a Raman spectrum that reveals how the molecules vibrate, rattle, rotate, and diffuse. We have been using this technique successfully to study, for example, room temperature ionic liquids, phase transitions, and the coherent dynamics of proteins. We will be applying this technique to either solutions or biomolecules. With our collaborators, we will be able to combine our OKE technique with the complementary technique of two-dimensional infrared (2D-IR) spectroscopy. The PhD student will be working alongside a team of postdoctoral researchers with experience in ultrafast techniques, chemical physics, and microscopy.
Organisations
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| EP/N509668/1 | 01/10/2016 | 30/09/2021 | |||
| 1791122 | Studentship | EP/N509668/1 | 03/10/2016 | 31/03/2020 | Andrew Farrell |
| Description | Observation of phase separation of brine (lithium chloride solution) and water at cryogenic temperatures. The first comprehensive characterisation of Giga-to-Terahertz dynamics of simple liquids, which are crucial in driving important biofunctions such as DNA melting, or chemical reactions in general. First direct and unambiguous observation of the so called "boson peak". The BP was believed to be a mysterious property of vitreous media, but we show it to be an ubiquitous feature of liquids too. |
| Exploitation Route | The liquid-liquid transition of water remains a hot topic in materials science. Our work on aqueous solutions can aid our understanding of H2O dynamics at conditions similar to the predicted liquid-liquid transition temperature and pressure. Our work on GHz to THz dynamics is extremely valuable to the field. Such dynamics are important for chemical and biological reactions, however their spectra are notoriously difficult to disentangle and interpret. This work provides a long overdue blueprint for the analysis of all low frequency dynamics. This blueprint will aid the interpretation of intermolecular vibrations and diffusion that occur within all liquids. Our uncovering of the BP in the glass and liquid phases show that the feature is likely common (although, probably hidden) to all liquids. |
| Sectors | Chemicals |
| Title | Intermolecular Dynamics |
| Description | We have developed the first single model that could effectively describe the intermolecular dynamical Raman spectra of a wide range of simple liquids, e.g. alkanes, cycloalkanes, and benzene. This provides the first ever blueprint for GHz to THz dynamics interpretation. |
| Type Of Material | Data analysis technique |
| Year Produced | 2020 |
| Provided To Others? | No |
| Impact | As a result, we have managed to isolate the so called "boson peak". A mysterious thermodynamic anomaly previously only witnessed in vitreous media. Our enhanced understanding of intermolecular dynamics enabled us to watch the behaviour of the boson peak from the glassy state all the way into the stable liquid phase, which has never been accomplished before. |
| Description | TRVS conference (Auckland, NZ) |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | The TRVS conference is a biennial event that gathers international experts in the field of time resolved vibrational spectroscopy. Our work on the boson peak from this grant was presented and discussed at this conference. |
| Year(s) Of Engagement Activity | 2019 |