Seminars

Find out about all of the upcoming seminars in the Department of Chemistry.

Dainton Building
Off

Autumn-Winter 2021

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.

September

Departmental seminar: Toward Reliable Modeling of Nonadiabatic Dynamics in Nanoscale Solar Energy Materials

29 September 14:00
Blackboard Collaborate

Speaker: Prof. Dr. Alexey Akimov
(University of Buffalo, NY)

Contact: Dr Natalia Martsinovich

Abstract

Quantum dynamics of excited states is critically important in many materials such as photovoltaic solar energy harvesters, photocatalysts, molecular electronics systems, or photo-actuated molecular switches. Electron-hole recombination, interfacial charge transfer, or nonradiative excitation energy relaxation, all require accounting for nonadiabatic (NA) effects. Computational modeling of NA and quantum dynamics (NA/QD) at the atomistic level can provide valuable insights into the mechanisms and kinetics of these processes and help design new materials with desired properties. The NA/QD modeling is computationally taxing, especially in nanoscale systems, and cannot be routinely applied. The demands for modeling NA/QD in periodic solids and nanoclusters stimulated the development of numerous approximations and led to the wide adoption of simplified computational schemes. However, it often remains unclear how the underlying approximations can affect the predicted “observables” extracted from the NA/QD calculations. The quality of such schemes remains largely unclear, leaving one questioning their reliability.

In this seminar, I will present our work on the NA/QD methodology development and assessment. Our focus will be on the techniques for NA/QD modeling in nanoscale and condensed-matter systems. First, I will introduce our Libra software as the platform for such methodology developments and assessment. I will highlight several new techniques and studies enabled by this platform. Then, I will focus on two topics of critical importance to NA/QD simulations: the choice of the density functional theory and the treatment of excitonic (many-body) effects. I will demonstrate and discuss the difference in computed nonadiabatic couplings exemplified by a series of Si quantum dots. I will then discuss the role of the many-body treatment of excited states in several types of materials, such as Si and CdSe nanoclusters, lead halide perovskites, and 2D phosphorene materials. The role of surface defects and surface ligands in the nonradiative relaxation of excited states will be discussed. A critical evaluation of the current methodologies and their limitations will be presented in view of the existing experimental studies.

October

Departmental Seminar: Tracking the Electronic and Energetic Requirements of Earth-Abundant Water Oxidation Catalysts for Artificial Photosynthesis

13 October, 13:00
Blackboard Collaborate

Speaker: Dr Dooshaye Moonshiram
(IMDEA)

Contact: Prof Anthony Meijer

Abstract

Replacing fossil fuels with renewable energy sources is one of the most promising research fields that can provide a solution towards solving the global energy crisis. Although today’s state of the art
technology has achieved progress in producing electricity using solar, wind, tidal, and hydroelectric power sources, these intermittent sources will find limited applications without proper energy storage and transport. One way of storing solar energy is to convert it into chemical energy through fuel forming reactions inspired by natural photosynthesis, such as the light induced water splitting into hydrogen and oxygen. The prospect of using molecular hydrogen as a carbon-free fuel has motivated the development of catalysts for photo-induced water oxidation, proton reduction, and their integration in catalyst-photosensitizer systems. However, although active synthetic efforts have been invested in developing efficient water splitting complexes, there is no clear understanding between their stability and performance to their structures and ligand geometries. In this context, time-resolved X-ray absorption with X-ray emission spectroscopy are powerful tools for visualizing the “real-time” electronic and geometric changes involved in a photocatalytic system with picosecond-microsecond time resolution. This talk will demonstrate the reaction pathways of several
cobalt, nickel and copper-based photosensitizer and hydrogen evolving complexes, examined in unprecedented detail with picosecond time resolution. The mechanistic pathways followed by these catalysts with spectroscopic and kinetic characterization of the different intermediates towards the hydrogen evolution pathway and H-H bond formation will be explained. Experimental results combined with theoretical simulations will reveal new aspects about the catalytic intermediates, and step by step time frames used for the hydrogen evolution reaction in purely aqueous conditions. Results shown will enable the rational design of molecular hydrogen-evolving photocatalysts that can perform beyond thcurrent microsecond time scale, and suggest ways in which the ligand structures can be adjusted to facilitate protonation and catalytic efficiency.


Departmental Seminar: Understanding the Light-Activated Processes of DNA Binding Transition Metal Polypyridyl Complexes Towards Diagnostics and Therapeutics

27 October 13:00
Blackboard Collaborate

Speaker: Susan Quinn
(University of Dublin)

Contact: Prof Julia Weinstein

Abstract

DNA interactions with metal polypyridyl complexes are of great interest due to their ability to (a) trigger photoinduced processes in DNA for photodynamic therapies, and (b) to signal the presence of DNA for imaging and diagnostic applications. We have extensively used time- resolved infrared (TRIR) to understand the excited state dynamics of these processes for
intercalating ruthenium dppz (dipyridophenazine) polypyridyl complexes bound to DNA. While the phenanthroline (phen) light-switch complexes can signal the presence of DNA the tetraazaphenanthrene (TAP) complexes can cause photodamage by participate in direct one-electron photo-oxidation of guanine and the yield of this process is sensitive to the local DNA environment and the binding orientation. However, the precise location of the metal complex is difficult to determine in solution, where multiple binding modes exist.
In this talk I will discuss how TRIR can be used to identify the binding site of photoactive metal complexes and show results for double stranded, quadruplex and imotif systems in solution. I will also show how TRIR is nicely complemented by structural and computational studies. Finally, I will discuss some very exciting recent results obtained for a chromium tetramethyl phenanthroline dppz [Cr(TMP) 2 dppz].Cl 3 complex, which can target both guanine and adenine bases.

November

Departmental Seminar: Electrochemical Generation of Complexes using Batch and Flow Technology

9 November 14:00 - NOTE THIS SEMINAR IS ON A TUESDAY
Blackboard Collaborate

Speaker: Dr Charlotte Willans
(Leeds)

Contact: Dr Seb Spain

Abstract

TBA


Departmental Seminar: Exploiting Physical Organic Principle in Selective Reaction Design

24 November 13:00
Blackboard Collaborate

 

Speaker: Dr Ryan Gilmour
(University of Munster)

Contact: Prof Anthony Meijer

Abstract

Controlling molecular space in 2- and 3-dimensions is a challenge that continues to be intensively pursued. In this lecture, contra-thermodynamic isomerisation via energy transfer catalysis will be discussed together with our latest contributions to the field of stereoelectronic conformational control. Molecular design strategies that profit from the intrinsic stereoelectronic and electrostatic effects of fluorinated organic molecules have mainly been restricted to bio-organic chemistry. Indeed, many fluorine conformational effects remain academic curiosities with no immediate application. However, the renaissance of organocatalysis offers the possibility to exploit many of these well-described phenomena for molecular preorganisation.

December

Departmental Seminar: The nature of chemistry publishing

8 December 13:00
Blackboard Collaborate

Speaker: Dr Stuart Cantrill
(Chief Editor - Nature Chemistry)

Contact: Prof Anthony Meijer

Abstract

This talk will take a behind-the-scenes look at Nature Chemistry’s editorial processes, as well as providing some guidance on preparing your paper, including titles, abstracts and graphical abstracts – there will also be some advice on how best to appeal an editorial decision. In addition, there will be a broader consideration of peer-review in general, the wider publishing landscape and also other aspects related to scientific publishing including metrics (impact factor, altmetrics, and so on) and the use of social media.

Short bio:

A graduate of the University of Birmingham in the UK, Stu obtained his PhD in chemistry from UCLA in 2001 (working with Fraser Stoddart), followed by postdoctoral research at Caltech (working with Bob Grubbs). In 2003, he returned to UCLA to tackle a number of different roles, including lecturer, research associate, administrative consultant to the California NanoSystems Institute as well as his first job in journal publishing — running an editorial office for the ACS journal Organic Letters. In 2006, Stu returned to the UK to join Nature Publishing Group (now Springer Nature) where he was first an associate and then senior editor at Nature Nanotechnology. In early 2008, he was appointed to be the founding Chief Editor of Nature Chemistry, which launched in April 2009. His main research interests were in the fields of supramolecular chemistry, self-assembly processes and interlocked molecules. His focus is now scholarly communication — particularly in chemistry — and how it might be changing in the not-too-distant future. 


 

Spring-Summer 2022

February

Departmental Seminar: Tuning Properties and Functionality in the Modulated Self-Assembly of Metal-Organic Frameworks

9 February 13:00 
Dainton LT-1 and Blackboard Collaborate

Speaker: Prof Ross Forgan
(University of Glasgow)

Contact: Dr Jona Foster

Abstract

Metal-organic frameworks (MOFs) are network materials comprised of organic ligands connected by metal ion clusters into multidimensional structures that often have permanent porosity. Their chemically addressable structures, combined with their ability to store large quantities of small molecules within their pores, have led to applications in gas storage, heterogeneous catalysis, sensing, and drug delivery, amongst others. Coordination modulation, the addition of monomeric modulators to synthetic mixtures, can tune particle size from nanometres to centimetres, through capping of crystallites (decreasing size) or coordinative competition with ligands (increasing size).

The talk will cover the development of our own modulation techniques for a range of trivalent and tetravalent MOFs, describing the versatility of modulation in controlling physical properties such as interpenetration, defectivity, and porosity. Our techniques provide access to high quality single crystals of many different MOFs, allowing the subsequent characterisation of their mechanical properties, flexibility upon guest uptake, single-crystal to single-crystal post-synthetic modification, and development of fluorescent sensors. Additionally, we will show that protocols can be tuned to downsize materials, producing nanoparticles with fine control of surface chemistry, allowing the assembly of pH-responsive and organelle targeted drug delivery devices.


Departmental Seminar: Discovery to market pipeline for bioinspired nanomaterials

23 February 13:00 
Dainton LT-1 and Blackboard Collaborate

Speaker: Dr Siddarth Patwardhan
(University of Sheffield)


Contact: Dr. Natalia Martsinovich

Abstract

There has been an explosion in nanomaterials discovery and synthesis, leading to many current and potential applications. A recent inventory has documented >5000 consumer products that contain nanomaterials. As such, large scale manufacturing of nanomaterials exists but it is limited to low-value products. Many high-value nanomaterials are available at lab-scale but cannot be scaled-up as they are energy and resource intensive, clearly highlighting the tension between achieving desired functionality yet sustainably and at large scale. On the other hand, biology produces sophisticated and functional nanomaterials in the form of biominerals under eco-friendly conditions and at scale. They use biomolecules, which play a crucial role in biomineral deposition. Therefore bioinspired approaches have the potential to resolve the functionality, sustainability and scalability conundrum and create disruptive technologies for manufacturing high-value nanomaterials. With selected examples, this presentation will focus on demonstrating how the discovery to market pipeline was created and used for bioinspired nanomaterials. Specifically, it will focus on:
1. Important molecular-level findings,
2. Design of materials for applications in medicine, energy and environment sectors,
3. Engineering advances made (sustainability, economics and scalability), and
4. Wider use of this “pipeline” methodology.

March

Departmental Seminar: Making and Breaking Chemical Bonds with Electron Rich Main Group Compounds

23 March 13:00
Blackboard Collaborate

Speaker: Prof Simon Aldridge
(University of Cambridge)

Contact: Prof Anthony Meijer

Abstract

The activation and functionalization of chemical bonds are critical fundamental processes which underpin chemical synthesis. While such processes have been exploited in catalytic fashion primarily through the application of late transition (‘Noble’) metal catalysts, other approaches involving ‘base’ 3d metals, frustrated Lewis pairs and Main Group elements have recently begun to emerge.
We have been interested in developing p-block compounds that possess ‘transition-metal-like’ attributes critical for the activation of small molecules: (i) small HOMO-LUMO gaps; (ii) high energy HOMOs for the activation of kinetically inert bonds; (iii) unpaired electrons; and/or (iv) redox properties appropriate for reversible bond formation. This work has led to the development of novel systems for the activation of industrially relevant small molecules such as dihydrogen, ammonia, carbon monoxide/dioxide and hydrocarbons such as benzene.

April

Departmental Seminar: Using and developing atomic force microscopy to understand soft and living matter

27 April 13:00
Dainton LT-1 and Blackboard Collaborate

Speaker: Professor Jamie Hobbs
(University of Sheffield)

Contact: Prof Anthony Meijer

Abstract

The atomic force microscope (AFM) has unique capabilities for the study of soft matter and biological systems. It can image in liquid or even physiological conditions; it can obtain resolution down to molecular or even sub-molecular length scale; it can be non-destructive so can be used to look at things that are alive or functioning; and it can measure forces with the sensitivity required to explore truly soft materials. In this talk I will give an overview of some of our work in these areas, concentrating on applications but diverting into how we have adjusted the instrument itself when appropriate. I will then explore two studies in more detail: firstly, the bacterial cell wall, how it is damaged by antibiotics, and how the hospital "superbug" MRSA gets round this damage to be antimicrobial resistant (AMR); secondly, what are the mechanical properties of breast cancer metastases in bone and can measuring tissue mechanics help us understand disease?​​​

May

Departmental Seminar: Bio-inspired and Sustainable Design: Towards Functional Materials

11 May 13:00
Blackboard Collaborate

Speaker: Dr LaShanda Korley
(University of Delaware)

Contact: Prof Tony Ryan OBE

Abstract

Materials that are found in Nature display a wide range of properties, including responsiveness to the environment, signal transmission, and the ability to adapt to support life. Learning from Nature or biomimicry can be a powerful tool in designing, developing and accessing the next generation of synthetic materials and systems. Using the bio-inspired framework, I will highlight several molecular design strategies utilizing cues from natural systems to generate gradient architectures, shape memory materials, and fibrous gels.  Extending this molecular engineering approach to sustainable design, I also will discuss research efforts to design performance-advantaged, bio-based thermoplastics and thermosets with potential applications in membrane technology and functional coatings.

Departmental Seminar: TBA

18 May 13:00
 Dainton LT-1 and Blackboard Collaborate

Speaker: Dr Izzy Jayasinghe
(University of Sheffield)

Abstract

TBA

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