From ultrafast processes in solar cells to prediction of meat quality: using spectroscopy and computational methods to understand complex systems
Keith C. Gordon, Royal Society of Chemistry Australasian
University of Otago, Department of Chemistry
Time & Place
Tue, 22 Oct 2019 11:00:00 NZDT in West 701
All are welcome
Vibrational spectroscopy is a potent method of analysing molecular structure within small volumes and at fast timescales. In this presentation I will try to cover off three related but distinct areas of interest.
Firstly, I will discuss how using a suite of spectroscopic methods, and by studying a series of complexes (metal-based donor-acceptor systems) in which parameters are carefully controlled,1 it is possible to develop design principles for excited state properties such that one can enhance electronic absorption and increase excited state lifetimes.2 Useful properties in both solar cells3 and photocatalysis. The understanding of how these properties, both ground and excited state, are modulated by driving force and effective conjugation is not straightforward.
Secondly, the use of computational chemistry in modelling properties of compounds has become ubiquitous in modern chemistry. However these do not always predict molecular behaviour effectively and unpicking the extent of deviation between theory and experiment reveals some interesting problems in our reliance on computational methods.4 Our studies on the spectroscopy of donor-acceptor and π, π* systems highlight these issues.5
Finally, our experimental development, originally aimed at understanding ground and excited state properties of metal complexes and other donor-acceptor systems, has provided us with tools that are amenable to analytical spectroscopy. We have used these tools in the study of primary produce and pharmaceuticals. More recently we have used low-frequency Raman spectroscopy6 to evaluate crystallinity (and order in general) in structures as varied as solar cell polymers7 to active pharmaceutical ingredients.8 Our studies in these areas will also be described.
- Larsen, C. B.; van der Salin, H.; Shillito, G. E.; Lucas, N. T.; Gordon, K. C., Tuning the Rainbow: Systematic Modulation of Donor-Acceptor Systems through Donor Substituents and Solvent. Inorg. Chem. 2016, 55, 8446-8458.
- Shillito, G. E., et al., Dramatic Alteration of 3(ILCT) Lifetimes Using Ancillary Ligands in Re(L)(CO)3(phen-TPA)(N+) Complexes: An Integrated Spectroscopic and Theoretical Study. J. Am. Chem. Soc. 2018, 140, 4534-4542.
- Chandrabose, S., et al., High Exciton Diffusion Coefficients in Fused Ring Electron Acceptor Films. J. Am. Chem. Soc. 2019, 141, 6922-6929.
- Barnsley, J. E.; Shillito, G. E.; Mapley, J. I.; Larsen, C. B.; Lucas, N. T.; Gordon, K. C., Walking the Emission Tightrope: Spectral and Computational Analysis of Some Dual-Emitting Benzothiadiazole Donor-Acceptor Dyes. J. Phys. Chem. A 2018, 122, 7991-8006.
- Huff, G. S.; Gallaher, J. K.; Hodgkiss, J. M.; Gordon, K. C., No Single Dft Method Can Predict Raman Cross-Sections, Frequencies and Electronic Absorption Maxima of Oligothiophenes. Synth. Met. 2017, 231, 1-6.
- Bērziņš, K.; Fraser-Miller, S. J.; Rades, T.; Gordon, K. C., Low Frequency Raman Spectroscopic Study on Compression-Induced Destabilization in Melt-Quenched Amorphous Celecoxib. Mol. Pharm. 2019.
- Sutton, J. J.; Nguyen, T. L.; Woo, H. Y.; Gordon, K. C., Variable-Temperature Resonance Raman Studies to Probe Interchain Ordering for Semiconducting Conjugated Polymers with Different Chain Curvature. Chem.-Asian J. 2019, 14, 1175-1183.
- Salim, M.; Fraser-Miller, S. J.; Sutton, J. J.; Be̅rziņš, K.; Hawley, A.; Clulow, A. J.; Beilles, S.; Gordon, K. C.; Boyd, B. J., Application of Low-Frequency Raman Scattering Spectroscopy to Probe in Situ Drug Solubilization in Milk During Digestion. J. Phys. Chem. Lett. 2019, 2258-2263.
Learn more about Keith Gordon here