Seminars

Find out about upcoming seminars in the Department of Chemistry.

Dainton Building
Off

January - May 2020

All departmental seminars are held in the Dainton Building, Lecture Theatre 1, unless stated otherwise. Departmental Seminars in Semester 2 will all be held at 12 noon.

January

Sheffield Stereochemistry 2020

14 January 10:00
Richard Roberts Auditorium


Cluster seminar: Deep Blue Organic TADF Emitters for Electroluminescent Devices

16 January 16:00
Dainton Building LT1

Speaker: Prof Eli Zysman-Colman
(University of St Andrews)

Contact: Prof Julia Weinstein

Abstract

The first generation OLEDs were based on organic fluorescent emitters. Their efficiency was intrinsically capped at 25% due to only being able to recruit singlet excitons. The second generation OLEDs have employed organometallic phosphorescent emitters, which harvest both singlet and triplet excitons for emission due to the enhanced intersystem crossing mediated by the heavy metals such as iridium(III) and platinum(II). 

These metal complexes possess very desirable optoelectronic properties and lead to very efficient OLED devices. However, the rarity of these metals, their high cost and their toxicity are important detracting features that inhibit large-scale, worldwide adoption of OLED technology, particularly for lighting where, unlike displays, low cost devices are crucial to market growth. The third generation OLEDs are based on small organic compounds that emit via a thermally activated delayed fluorescence (TADF) mechanism. As with phosphorescent emitters, OLEDs using these emitters can recruit 100% of the excitons. In this presentation, we present our recent efforts towards blue emitter in electroluminescent devices.


Industrial seminar: How did I end up doing engineering? From the CDT to Industry

22 January 14:00
Dainton Building LT1

Speaker: Dr. Luke Fox
(JaguarLandRover)

Contact: Dr Jennifer Dick

Abstract

Dr Luke Fox is a Sheffield and CDT for Polymers, Colloids and Soft Matter alumnus. Having studied Chemistry at the University of York with a placement at AkzoNobel working on polymers, he then joined the CDT in 2014 at the University of Sheffield for his PhD. Luke’s PhD was investigating the use of polypropylene in an emerging Additive Manufacturing technique, as a part of the first cohort of students through the CDT at Sheffield.

Having enjoyed his time at the university and academic life, he decided to move into industry and join Jaguar Land Rover to work as an internal technology consultant, with the opportunity to apply what he had learnt through his research and studies into rapidly developing area of manufacturing. In his talk, he will discuss the differences between academic and industrial life, the issues facing large-scale automotive manufacturers and how technology can be used to tackle these problems. He will also comment on what happens to companies that are affected by financial difficulties and what this can mean for their employees.


Theory and Light-Matter Interactions Cluster Seminar: On the importance of intermediate states in the TADF mechanism: the more the better?

23 January 13:00
Dainton Building LT1 

Speaker: Dr Julien Eng
(University of Newcastle)

Contact: Dr Julia Weinstein

Abstract

Thermally Activated Delayed Fluorescence (TADF) has been investigated in the last years as an efficient mean of harvesting the 75 % of triplet population generated upon electrical excitation of an OLED [1]. While the TADF mechanism can be thought as a "simple" reverse intersystem crossing (rISC) between one singlet and one triplet state (S 1 and T 1 ), it has been shown that the underlying mechanism may not be as trivial as that. Indeed, in the hope of minimising the S 1 /T 1 energy gap, and to favour TADF, efforts have been put in the design of Donor(D)-Acceptor(A) type molecules exhibiting low lying charge transfer states.

However, such design presents other drawbacks. Indeed, the spin-orbit coupling (SOC) between states of same nature and different spin multiplicity vanishes and leads to a decrease of the rate of rISC. Even though this direct pathway (S 1 ⇋T 1 ) is closed, alternative routes via close-lying electronic states may provide a way of rISC [2,3]. Multiplying the number of D or A units in order to provide additional secondary pathways for the transfer of population has been the focus of several studies.


In this talk, we first investigate the excited states topology and properties of a D-A [2,3], a D-A-D [4] and a D-A 3 [5,6] organic systems.

February

Theory and Light-Matter Interactions Cluster Seminar: 
Adventures in ultrafast laser spectroscopy at the CLF – new multidimensional IR techniques and new applications in heterogeneous catalysis and ionic liquid research

5 February, 1pm
Dainton Building, LT1

Speaker: Dr Paul Donaldson
Central Laser Facility

Contact: Professor Julia Weinstein

Abstract

2D-IR spectroscopy is able to probe molecular equilibrium structural dynamics and fluctuations on timescales as short as femtoseconds. In this talk it will be shown how the technique can be used to probe the dynamics of small molecules near Zeolite acid sites and in protic ionic liquids. 2D-IR methods also show molecular couplings in a similar fashion to the spin couplings of 2D NMR. This aspect of 2D-IR will be discussed and a new form of 2D-IR spectroscopy developed at the CLF for probing vibrational couplings will be introduced.


Industrial Seminar:
Life after specialisation: a non-linear career in science

12 February 14:00
Dainton Building LT1

Speaker: Dr. Gianfranco Unali
(Unilever)

Contact: Dr Jennifer Dick

Abstract

A look at two decades as an industrial Science & Technology researcher at Unilever: how deviation from the obvious career path has led to a varied and fulfilling career. From Synthetic Chemistry to Physical Chemistry to EU Projects to Disruptive Innovation, Agreements and Contracts and Pseudo Start-ups. However, there’s a caveat: choose your time well and be clear about your motivation.


Departmental Seminar:
New methods for studying battery function and degradation

13 February 12:00
Dainton Building LT1

Speaker: Prof Clare Grey FRS
(University of Cambridge)

Contact: Prof Patrick Fowler FRS

Abstract

This talk will describe techniques developed to study battery processes in situ and the study of electrode materials optimised for safe, fast charging. The second half of the talk will describe approaches developed to understand how EV batteries function and studies aimed at identifying and mitigating key degradation mechanisms

Clare was awarded the 2019 John B Goodenough Award by the RSC, for her  ‘pioneering and innovative uses of magnetic resonance methods to study structure and dynamics in electrochemical devices.'


Departmental Seminar:
Production of Metal-Organic Frameworks using Microwave Technology

27 February 12:00
Dainton Building LT1

Speaker: Dr Andrea Laybourn
University of Nottingham

Contact: Dr Rob Dawson

Abstract

Metal-organic frameworks (MOFs) are porous materials that show great potential for a wide-range of applications including gas storage and separations, pollutant removal, catalysis, and sensing. However, current states of the art in manufacture have restricted widespread adoption of MOFs for industrial applications, as at scale they deliver poor reproducibility in quality, whilst incurring high energy and capital costs for manufacture meaning that none of the proposed applications are currently economically viable.

The development of technologies that reduce the cost of manufacture in an efficient and sustainable way is a key enabling step in the transfer of MOF research from the laboratory to industrial application. Microwave technology shows great promise for scale up of MOFs as it offers benefits over other methods including significantly reduced reaction times (from hours to seconds), high space time yields and energy efficiency.

This presentation discusses our progress in the synthesis of MOFs using microwave technology, including investigations of the interaction between microwave energy and MOF reactants, studies on the mechanism by which MOFs are produced, and recent progress towards the development of continuous flow microwave reactors for the production of MOFs on the hundreds of grams scale. Notably, our reactors are capable of producing MOFs on astonishing timescales (as low as 2.2 seconds) with a high level of control over MOF properties such as porosity, morphology, particle size and phase; achieved by altering the applied power, treatment time and mixing conditions, all of which are vital for processing MOFs for practical applications.

March

Industrial Seminar: Aqdot – a spin-out story: Taking university science to commercial products using supramolecular chemistry.

11 March 14:00
Dainton Building LT1

 

Speaker: Ben Cheesman
(Aqdot)

Contact: Dr Jennifer Dick

Abstract

Ben will describe an overview of the journey of Aqdot from a neat scientific concept in the Department of Chemistry at the University of Cambridge, to a fully-fledged commercial entity that produces new chemicals to exploit supramolecular chemistry.  The talk will first describe the original concept that generated the excitement and funding for Aqdot’s foundation: templated capsules via single-step, directed self-assembly for encapsulation and triggered release.  Next, the various challenges to be overcome to develop a viable company selling real products: these include regulatory hurdles, patent strategy, and scaling up.  It will be clear that a combination of sound planning to set direction and agility to respond to realities is required.  The final part of the talk will outline the approaches to moving from pathfinder products to commercial viability with several product lines designed for stopping smells, looking good, and curing cancer.

The talk should be of particular interest to anybody interested in supramolecular chemistry and the journey from idea to commercial reality.

Dr Ben Cheesman received an MChem and PhD in polymer chemistry from the University of Bristol.  After a two-year post-doc position at the University of Newcastle, Australia, he returned to the UK and started his industrial career in 2013 at Aqdot where he is now the Project Leader of the New Product Development team.

 
April

Departmental Seminar: Dynamic Effects and Machine-Learning Transition State Theory

26 April 16:00
Blackboard Collaborate

Speaker: Prof. Daniel Singleton
Texas A&M University

Contact: Prof Anthony Meijer

Abstract

The central focus of the Singleton research group is the study of organic, organometallic, and bioorganic reaction mechanisms, and the key tool that we use in these studies is the determination o kinetic isotope effects (KIEs). In the mid-1990's, we developed a method for the high precision combinatorial determination of small KIEs at natural abundance by NMR. Its direct applicability to complex unlabeled reactants makes this methodology 1-2 orders of magnitude faster than studies requiring labeling. At the same time, it is much more versatile - our technique can look at a great number of reactions that would have been impractical or impossible to study by labeling or mass spectral methods, and the choice of reactants can be readily changed in response to each new experimental result. The simultaneous determination of a complete set of 13C, 2H, and 17O isotope effects possible with our methodology provides a much greater level of information than available from conventional methods. In addition, substantial evidence has accumulated supporting the reliable accuracy of our results.

A related advance has been theoretical - the discovery that excellent predictions of KIEs are possible, provided that the calculated transition structure accurately reflects the mechanism. This has allowed us to use KIEs to provide an experimental basis for transition state geometry. The combination of our experimental methodology and theory has repeatedly been successfully applied to resolve controversies, to experimentally establish critical details of important reaction mechanisms, and to find new mechanisms for basic reactions.

The cutting edge in our group is the study of dynamic effects in ordinary reactions in solution. As we have studied reaction mechanisms, we have found that the conventional framework for understanding reactions using transition state theory is often not adequate, and we have found that dynamic effects play a role in organic reactions much more often than currently thought. In studying such reactions, our goal is to revise the fundamental understanding of reactivity and selectivity in organic chemistry.


Departmental Seminar: Developing Novel Oxygenating and Bio-instructive Multicomponent Synthetic Extracellular Niches for Periodontal Regeneration

30 April 13:00
Blackboard Collaborate

Speaker: Dr Babatunde Okesola
(Queen Mary University of London)

Contact: Prof Anthony Meijer

Abstract
Dr Okesola's work lies in the area of polymer chemistry, in particular the use of hydrogels for use in tissue regeneration and biomineralisation scaffolds.

 

May

Departmental Seminar: TBA

7 May 13:00
Blackboard Collaborate

Speaker: Prof Tony Ryan
University of Sheffield

Contact: Prof Anthony Meijer

Abstract
Prof Ryan will be talking about his work with refugees in the Al-Zataari camp in  Jordan.


Departmental Seminar: TBA

14 May 13:00
Blackboard Collaborate

Speaker: Dr Milan Delor
Columbia University (NY)

Contact: Prof Anthony Meijer

Abstract

The ability of energy carriers to move within and between atoms and molecules underlies virtually all material function. Understanding and controlling energy flow requires observing it on ultrasmall and ultrafast spatiotemporal scales, where energetic and structural roadblocks dictate the fate of energy carriers. I will describe a new optical ultrafast microscope based on stroboscopic elastic scattering that enables direct visualization of energy carrier transport in 3D with few-nanometre spatial precision and picosecond temporal resolution.1 I will demonstrate the wide applicability of the method for watching all forms of energy carriers – free charges, excitons, phonons and ions – move in materials ranging from silicon to conjugated polymers via 2D transition metal dichalcogenides and metal halide perovskites. Beyond quantifying carrier mobilities, our approach directly correlates material resistivities to local morphology, shedding light on how disorder affects transport pathways in 3D. I will conclude by describing the burgeoning efforts in my lab to visualize single electrons and defects in materials and to integrate targeted structural2 and electromagnetic perturbations to actively direct energy flow over device-relevant length-scales. 

  1. Delor, Weaver, Yu, Ginsberg. “Imaging material functionality through three-dimensional nanoscale tracking of energy flow”. Nature Materials, v. 19, pp. 56-62 (2020).
  2. Delor, Scattergood, Sazanovich, Parker, Greetham, Meijer, Towrie, Weinstein. “Toward control of electron transfer in donor-acceptor molecules by bond-specific infrared excitation”. Science, v. 346, pp. 1492-1495 (2014).

Departmental Seminar: Two sides of the same story - time-resolved spectroscopy and theory applied to the activation of [FeII(N4Py)]2+

21 May 13:00
Blackboard Collaborate

Speaker: Prof. Marcel Swart
University of Girona

Contact: Prof Anthony Meijer

Abstract

Volatile first-row transition metal complexes such as superoxo or hydroperoxo complexes have been characterized through X-ray crystallography (rarely) and spectroscopy. Through isotope shifts of vibrational spectroscopy characteristic fingerprint bands were observed, which are typically found in the region 700-900 cm-1 for peroxo species and 1000-1400 cm-1 for superoxo species. Often the peroxo and superoxo species show different coordinations towards the metal, and different reactivities, the origin of which is not fully understood. In order to gain deeper insights of the effect of the spin and oxidation state of the metal, the nature and type of coordinating ligands, an overview will be presented of spectroscopic features and reactivity of selected transient TM-complexes that have been characterized[2-7] by both time-resolved spectroscopy and spin-state consistent density functionals.
The main part will focus on the activation of hydrogen peroxide by the [FeII(N4py)]2+ complex, which involves a multitude of processes at different timescales (<2s, ca. 100s, 1 hr). Through detailed spectroscopic and computational chemistry studies we have been able to describe the steps that are taking place within the activation of peroxides, cycling through a plethora of iron oxidation and spin states.


Departmental Seminar: Harnessing Conformational Dynamics to Engineer New Enzymes

28 May 14:00
Blackboard Collaborate

Speaker: Prof. Lynn Kamerlin
Uppsala University

Contact: Prof Anthony Meijer

Abstract

Understanding how new enzyme functions evolve, either on existing scaffolds, or completely de novo on previously non-catalytic scaffolds, is of great interest both from a fundamental biochemistry perspective, and from a biotechnological perspective. Several hypotheses have been put forward to rationalize enzyme evolution, one of which is that their conformational
dynamics plays an important role in facilitating the emergence of new enzyme functions. My team and I have invested substantial research effort into understanding enzyme multifunctionality in catalytically promiscuous enzymes, as well as the structure-function-dynamics relationships shaping the evolution of new enzyme functions, in both natural an engineered active sites. In this talk, I will discuss recent progress in this area, and illustrate how we have engineered conformational dynamics to generate a a de novo active site capable
of catalysing a non-natural reaction, and then subsequently enhanced this activity using a simple computational approach, reaching catalytic efficiency comparable to that of naturally occurring enzymes.

Summer 2020

June

Departmental Seminar: Synergistic Cooperation between Mechanistic Investigations and Catalysis: Finding the Opportunity in the Middle of the Difficulty

11 June 13:00 
Blackboard Collaborate

Speaker: Dr Mónice Pérez Temprano
ICIQ

Contact: Prof Anthony Meijer

Abstract

The sustainable synthesis of relevant organic scaffolds for their use in the pharmaceutical, agrochemical and materials sectors constitutes one of the most urgent challenges that the chemical community needs to overcome. Our ideal approach to tackle this problem is the rational design and development of catalytic processes based on fundamental mechanistic understanding. Surprisingly, this strategy remains a largely unresolved challenge for academic and industrial chemists.
This talk will describe our recent efforts not only to provide critical mechanistic information on well-known reactivity, but also to understand, discover, design and develop more efficient transition metal-catalyzed reactions by trapping and/or synthesizing key reaction intermediates and using them as “knowledge building blocks” for rational design.


Departmental Seminar: Realtime tracking of the electron dynamics in molecules

18 June 13:00 
Blackboard Collaborate

Speaker: Prof. Francesca Caligari
DESY/University of Hamburg

Contact: Prof Anthony Meijer

Abstract

Observing electron dynamics in matter on its natural time scale requires attosecond technology. I will show how isolated attosecond pulses can be used in combination with phase-stable infrared/ ultraviolet pulses to track ultrafast charge dynamics in bio-relevant molecules such as aromatic amino acids. These scheme can be also used to investigate the ultrafast mechanisms behind the photo stability of our own DNA. Our results open new important perspectives for a future understanding of the role of the electronic motion in the photochemistry and photobiology of complex molecules.

July

Departmental Seminar

1 July 2020 14:00
Blackboard Collaborate

Speaker: Prof Tony Ryan
University of Sheffield

Contact: Prof Anthony Meijer

Abstract
Prof Ryan will be talking about his work with refugees in the Al-Zataari camp in  Jordan. This seminar was rescheduled due to technical problems on the 7th May.

A world top-100 university

We're a world top-100 university renowned for the excellence, impact and distinctiveness of our research-led learning and teaching.