Seminars
Find out about all of the upcoming seminars in the Department of Chemistry.
Autumn-Winter 2022
All departmental seminars are held via Blackboard Collaborate, unless stated otherwise. Departmental Seminars will all be held on Wednesdays. Please always check the time as it might change for some speakers.
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September
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Departmental seminar: Molecular-scale optical imaging tools for decoding cellular signalling
28 September 13:00
Dainton LT1 and Blackboard CollaborateSpeaker: Dr Izzy Jayasinghe
(University of Sheffield)
Contact: Dr Tim CraggsAbstract
In this seminar, I will outline how the continued improvement and strategic adaptation of super-resolution microscopy tools have enhanced our understanding of the nanoscale structures underpinning life. I will illustrate some of these advances with examples where super-resolution modalities have allowed us to better visualise ryanodine receptor (RyR) nanodomains in tissues like the heart, muscle and neural tissues. Correlative structure-function imaging has allowed us to resolve, count and identify the RyR clustering patterns which spatially encode the fast calcium signals within the cells.
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October
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Departmental Seminar: The identification, development, and first steps towards commercialisation of ruthenium(II)-based antimicrobials.
12 October 13:00
Dainton LT1 and Blackboard CollaborateSpeakers: Prof Jim Thomas and Dr Kristy Smitten
(University of Sheffield and MetalloBio Ltd)
Contact: Prof Anthony MeijerAbstract
Antimicrobial Resistance, AMR, is a rapidly emerging global emergency. Indeed, it has been suggested that infections with AMR pathogens are already the third largest underlying cause of death in the world. If this continues unchecked, many of the advances of modern medicine will be reversed, as what are now minor infections and routine medical procedures will become potentially fatal. The Thomas group has identified two related molecular architectures based on simple metal complexes that display antimicrobial activity. These broad-spectrum leads are highly potent and retain their activity in a wide range of AMR bacteria, including those at the top of the World Health Organization's list of high priority pathogens that urgently require new treatments. In this talk we will outline their identification, development, and the first steps toward their commercialization through a spin-out company, MetalloBio Ltd.
Departmental Seminar: Cold Atmospheric Plasma as an exciting new medical technology - the good, the bad and the ugly.
26 October, 13:00
Dainton LT1 and Blackboard CollaborateSpeaker: Prof Rob Short
(University of Sheffield)Contact: Prof Anthony Meijer
Abstract
The rise of antimicrobial resistance, a rapidly ageing population and rising health cost threaten the long-term sustainability of healthcare systems globally. For example, non-healing and infected wounds currently cost the NHS > £3-4bn pa. This, along with quality of life and resources consumed, will only worsen with the increase in conditions such as diabetes and obesity. Anti-microbial resistance has profound implications for wounds, as infection remains a major problem. Without replacements for “failing” antibiotics, it is anticipated that by 2050 there will be 10Ms of additional (ie avoidable) deaths as a result.
Innovative and potentially curative approaches to augment traditional drug-centric treatments have been the focus of my research now for over 25 years, with a focus on tissue repair and wounds.In this seminar, I will talk about a topic that I started researching exactly a decade ago: the use of cold atmospheric plasma (CAP) (electrically-excited gas) to treat disease. CAP shows promise as a new medical technology and is the basis of the rapidly growing field of plasma medicine. CAP can be used to deliver biologically-important molecules, such as NO (important in tissue repair and cell signalling), H2O2 (promotes cell growth/destroys micro- organisms), or reactive species such as the OH radical or atomic oxygen (both kill cancer cells), deep into diseased tissue.
CAP has shown potential in the treatment of chronic wounds,1,3 and cancers and as well as applications in other diseases (autoimmune) and in biotechnology. CAP offers a viable approach to resolve deep tissue infections. Whilst there is significant optimism that CAP can provide the basis of a new medical technology, there is also a real and present danger of over-selling and under-delivering.
Challenges include gaps in our knowledge, in terms of mode of action and of CAP-tissue interactions over a range of scale lengths (μm-cms). These gaps are set to hamper progression in the development of the technology, in the design of clinical trials and credibility with, and adoption by, the medical community. I will discuss my investigations of plasma-tissue interactions at the University of South Australia, and how I am now, through a multi-university collaboration, developing a novel CAP–materials platform that releases potent pharmaceutical agents deep into tissue. The commercial potential of this approach, including overcoming the limitations of applying plasma directly onto human tissue, will be captured through the spinout venture, Plasma4 Ltd., with a first in-man trial anticipated in 2023.
I will also cover some earlier interests in plasma polymerisation4 and the development of cell delivery devices for treating severe burns and scalds (from my first stint at the University of
Sheffield, 17 years ago), to more recent, emerging interests such as exploring the fate of microplastics (a topic entirely new to me!), where these particles not only present a potential health hazard (the jury is out) but also offer a vector for disease transmission and promoting antimicrobial resistance.Departmental Seminar: TBA
October 13:00
Blackboard CollaborateSpeaker:
Contact:Abstract
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November
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Departmental Seminar: Tailoring the Photophysics of First-row Transition Metal-based Chromophores for Applications in Light-to-Chemical Energy Conversion: Challenges and Opportunities
7 November 13:00
Firth Court, David Rice Lecture Theatre F02 and Blackboard CollaborateSpeaker: Prof Dr. James K. McCusker, FRSC
(Michigan State University)
Contact: Prof Julia WeinsteinAbstract
The interconversion of light and chemical energy is one of the most fundamental processes on Earth. Research on solar energy conversion, for example – which will ultimately lead to the next generation of solar energy technologies – has sought to replicate Nature’s solution through the realization of artificia constructs that mimic various aspects of photosynthesis. Whether it is the
creation of potential gradients to generate current (i.e., photovoltaics) or more recent efforts coupling photo-generated electrons and holes to catalysts (e.g., photoredox catalysis), the critical first step is the absorption of light and the subsequent separation of charge. Transition metal-based chromophores are particularly well-suited for use in such schemes by virtue of the charge-transfer excited-states that a majority of them possess. Indeed, tremendous advances have been made through use of compounds such as [Ru(bpy)3]2+ and Ir(ppy)3 in areas ranging from solar energy
conversion to photoredox catalysis. Despite the obvious advantages of ruthenium- and iridium-based chromophores, the fact that these elements are among the rarest in the earth’s crust raises legitimate questions concerning cost and scalability of processes reliant on such chromophores.
Such issues, coupled with the possibility of unlocking new chemistry, has motivated efforts addressing the possibility of replacing these compounds with chromophores based on earth-abundant first-row transition metals that can carry out analogous excited-state reaction chemistry. With these opportunities come significant challenges due to inherent differences in the electronic structures of first- versus second- and third-row metal complexes that profoundly impact the ability of such compounds to engage in the desired chemistry. The focus of our research program is to understand the factors that determine the dynamics associated with the excited states of first-row transition metal-based chromophores with the ultimate goal of circumventing and/or redefining
their intrinsic photophysics in order to make feasible their use in a variety of light-driven applications. This seminar will outline the key scientific issues defining this challenge as well as discuss recent examples from our lab illustrating how these challenges can be met and, ultimately, overcome.Departmental Seminar: Proton-Coupled Electron Transfer in Natural and Artificial Photosynthesis
23 November 13:00
Blackboard Collaborate
Speaker: Prof Leif Hammarström
(Uppsala University)
Contact: Prof Julia WeinsteinAbstract
Proton-coupled electron transfer (PCET) reactions are fundamental to energy transformation reactions in natural and artificial systems and are increasingly recognized in areas such as catalysis
and photoredox catalysis. The coupled transfer of electrons and protons are often energetically advantageous, as it allows for charge neutral redox reactions in low-polarity environment, and the accumulation of redox equivalents without building up charge. The coupled transfer has substantial impact on the reaction rate, due to modulations of the reaction energy barrier as well as the strong
dependence on the distance the proton has to tunnel during the reaction. I will give a background how to understand the origin and consequences of the coupling in simple chemical terms, using examples from natural and artificial photosynthesis. I will furthermore discuss how to experimentally distinguish different PCET mechanisms, and why a particular mechanism dominates, an
understanding which is crucial for the design and optimization of reactions that use PCET [1].
In recent collaborative work, we gave the first and still only example of PCET in the Marcus Inverted Region (MIR), where the rate decreases with increasing driving force [2]. This is believed to be important to maintain a long-lived photosynthetic charge separation, but earlier predictions suggested that observation of MIR for PCET is unlikely. Finally, I will present our recent discovery of a novel
elementary reaction, which we denote Proton-Coupled Energy Transfer (PCEnT) [3]. The understanding of the PCEnT reaction and its wider implications will be discussed.
(1) R. Tyburski, T. Liu, S. D. Glover, L. Hammarström, J. Am. Chem Soc. 2021, 143, 560. (Perspective)
(2) Parada, G. A.; Goldsmith, Z. K.; Kolmar, S.; Rimgard, B. P.; Mercado, B. P.; Hammarström, L.; Hammes-Schiffer, S.; Mayer, J. M. Science 2019, 364, 471.
(3) Rimgard, B. P., Tao, Z.; Cotter, L.; Parada, G. A.; Mayer, J. M.; Hammes-Schiffer, S.; Hammarström, L., Science, 2022, 377. 742. -
December
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Departmental Seminar: New methods for studying ion–neutral reactions at low temperatures
7 December 13:00
Blackboard CollaborateSpeaker: Dr Brianna Heazlewood
(University of Liverpool)
Contact: Dr Adrien ChauvetAbstract
In spite of their real-world importance, very few experimental methods can be applied to the precise study of gas-phase reactions between ions and radicals. One of the reasons for this is the challenges associated with generating a pure beam of gas-phase radicals with tuneable properties. In this talk, I will present our approach to generating beams of velocity- and state-selected radicals [1-2]. We are in the process of combining a radical beam source with a cryogenic ion trap, for the study of ion-radical reactions under cold and controlled conditions. Reactions will take place within Coulomb crystals, enabling us to monitor processes with exceptional sensitivity (down to the single-ion level). Recent work on some 'simple' ion-neutral reactions will be discussed [3], revealing the advantages of studying reaction processes within Coulomb crystals.
(1) J. Toscano, C. J. Rennick, T. P. Softley, and B. R. Heazlewood, “A magnetic guide to purify radical beams” J. Phys. Chem., 149, 174201 (2018).
(2) C. Miossec, L. Y. Wu, P. Bertier, M. Hejduk, and B. R. Heazlewood, “A stand-alone magnetic guide for producing tuneable radical beams” J. Chem. Phys., 153, 104202 (2020).
(3) A. Tsikritea, K. Park, P. Bertier, J. Loreau, T. P. Softley, and B. R. Heazlewood, “Inverse kinetic isotope effects in the charge transfer reactions of ammonia with rare gas ions” Chem. Sci., 12, 10005 (2021).
Spring-Summer 2023FebruaryDepartmental Seminar: TBA
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March
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Departmental Seminar: TBA
8 March 13:00
Dainton LT-1 and Blackboard CollaborateSpeaker: Dr Julia Sarju
Contact: Dr Natalia Martsinovich
Abstract
TBA
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Departmental Seminar: TBA
15 March 13:00
Dainton LT-1 and Blackboard CollaborateSpeaker: Professor Chris Willis
Contact: Dr Ben Partridge
Abstract
TBA
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April
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Departmental Seminar: TBA
4 April 13:00
Dainton LT-1 and Blackboard CollaborateSpeaker: Dr Marc Reid
Contact: Professor Nick Williams
Abstract
TBA
Departmental Seminar: TBA
19 April 13:00
Dainton LT-1 and Blackboard CollaborateSpeaker: Dr Louis C. Morrill
Contact: Dr Ben PartridgeAbstract
TBA
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May
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Departmental Seminar: TBA
10 May 13:00
Dainton LT-1 and Blackboard CollaborateSpeaker: Professor Emma Kendrick (RSC prize winner)
Contact:
Abstract
TBA
Departmental Seminar:
May 13:00
Dainton LT-1 and Blackboard CollaborateSpeaker:
Contact:
Abstract