Past Seminars 2012-2013

11 October 2012

Safety Lecture: Experimenting with Danger

Following three very serious accidents that occurred in US university chemical laboratories, the US Chemical Safety Board produced a report in the form of a video. Although safety legislation and practices differ between the UK and the US, this report provides important lessons on safety for anyone working or managing work within a research laboratory. We will view the report and then have a short discussion on the implications for our working practices in Sheffield. All students and staff working within research laboratories are encouraged to attend and input to the discussion.

Professor Richard Jackson and Dr Jane Grasby

Safety Lecture

RSC de Gennes Prize lecture:
Soft Matter Chemistry at the Proto-life/Synthetic Biology Interface

Speaker: Prof. Stephen Mann - Centre for Organized Matter Chemistry, School of Chemistry, University of Bristol, Bristol.

In this talk, I review some recent studies undertaken in my laboratory that address the interface between proto-life research and synthetic biology. Two themes will be considered. Firstly, can proteins with biomimetic potential maintain their structure and function in the absence of water (or any other solvent) whilst retained in the liquid state? And secondly, can protocell models be constructed based on bioinspired materials design and construction?

RSC awards lectures

Presidential Address:
Learning to Train Snakes - Understanding the Peculiar Behaviour of Polymers

Speaker: Dr. Colin Crook

Physical factors affecting (in vitro) structures in protein aggregation

Speaker: Prof. Athene M Donald, DBE FRS, Cavendish Laboratory, University of Cambridge

Whereas the formation of amyloid fibril formation from denatured protein solutions is well documented, in fact there are a variety of different structures that may form depending on circumstances, and these varied structures can also be detected in the pathology of disease. We have been looking at the physical factors that control the different states of aggregation: these include electrostatic effects and mechanical energy input. As well as free fibrils, suprafibrillar aggregates - termed spherulites - can form, and also birefringent gels under flow. Much of our work has been on the model proteins beta lactoglobulin and insulin, but A beta - the protein fragment associated with Alzheimer's Disease - is found to behave in a similar fashion.

Fireworks Lecture

Speaker: Prof. Jacqueline Akhavan, Department of Defence and Security, Cranfield University, Shrivenham.

Cellulose nanowhiskers: Source, properties and potential uses

Speaker: Prof. Stephen Eichhorn, Department of Materials Science, University of Exeter.

Cellulose nanowhiskers (CNWs) are derived by the acid hydrolysis of plant based cellulose (and animal and bacterial forms) and are slender rod- like fibrous materials that exhibit interesting properties. This talk will review work done to determine their mechanical properties (modulus) and interfaces with other polymers. Given their aspect ratio and potential high modulus CNWs can be used for composite materials. Efforts to understand better the interface between CNWs and polymers will be presented, as well as attempts to orient them using magnetic fields, wet-stretching and spin-coating. Spin-coating monolayers of CNWs provides nano-templated surfaces onto which human muscle cells can be aligned, providing potential for tissue engineering applications. Finally, some recent work to probe the properties of cellulose nanowhiskers has led to questions over the role of other forms of interaction in the wood cell wall that have been neglected e.g. hydrophobic interactions. This work may lead to clues as to why the wood cell wall appears to be so recalcitrant.

Research Cluster Seminar

22 Nov 2012

Photosynthetic Antennas: The First Step in Biological Solar Energy Conversion

Speaker: Prof. Robert E. Blankenship, Washington University, St. Louis, USA

All photosynthetic organisms contain a light-gathering antenna system, which functions to collect light and deliver energy to the photosynthetic reaction center, where electron transfer processes store chemical energy. There are a large number of different types of antenna complexes, which have almost certainly arisen multiple times during evolution to adapt organisms to particular photic environments. The antenna system that will be discussed in this talk is the chlorosome antenna and the associated FMO protein that is an intermediate in energy transfer between the chlorosome and the reaction center in green sulfur bacteria. This protein has been found to exhibit electronic quantum coherence effects, which may be important in its function. Advanced mass spectrometry methods have been used to determine the orientation of this protein in the intact photosystem, the cofactor composition of the native complex and how it interacts with the chlorosome and reaction center.

28 Nov 2012

14.00 to 18.00

RSC Faraday Awards Symposium

Speakers:

Prof Robert Best (National Institutes of Health) – Marlow Award
Prof Greg Scholes, University of Toronto – Bourke Award
Prof Arieh Warshel, University of Southern California – Soft Matter and Biophysical Award

Synthesis and Supramolecular Chemistry of Cyclic Peptides

Speaker: Prof. Kate Jolliffe, School of Chemistry, University of Sydney, Australia.

Peptides are Nature's scaffolds.They are used to position functional groups in a spatially well-defined manner to facilitate recognition between molecules (e.g. protein-small molecule and protein-protein interactions). We have employed cyclisation as a means to control the conformations of small synthetic peptides to enable us to mimic these types of interactions between molecules. The synthesis, anion binding properties and self assembly of several classes of cyclic peptide will be presented

Polymeric nanostructures: synthesis, characterisation and applications in synthesis

Speaker: Prof Rachel O’Reilly, Department of Chemistry, University of Warwick.

In the O’Reilly group we are interested in preparing functional and responsive amphiphilic diblock copolymers which have unique properties such as responsive capabilities, catalytic activity or selective recognition. Furthermore we are interested in the solution self assembly and the characterization of the resultant aggregates along with their exploration in a range of applications such as in controlled release and also sensor applications

Departmental Seminar

Quantum Chemical Topology: constructing a novel force field with malleable atoms

Speaker: Prof Paul Popelier, Manchester Institute of Biotechnology, School of Chemistry, University of Manchester.

In this talk I will show how ideas from quantum chemistry can be used to enhance the realism of a protein force field[1], with emphasis on effects of polarization on electrostatic energy. Quantum Chemical Topology (QCT) [2-4] is a method [5,6] that partitions the electron density into so-called topological atoms, using the insights of dynamical systems. A molecule such as glycine can partitioned into topological atoms. There are no gaps between these atoms and they do not overlap. Each atom is a box with a particular shape and a finite volume. If the coordinates change then the shapes of the atoms change too, as well as their electric multipole moments. This complex relationship is captured by machine learning. Topological atoms can be regarded as macroscopic objects, malleable and open.
(1) Mills, M. J. L.; Popelier, P. L. A. Theor.Chem.Acc. 2012, 131, 1137-1153
(2) Popelier, P. L. A.; Bremond, E. A. G. Int.J.Quant.Chem. 2009, 109, 2542–2553
(3) Popelier, P. L. A.; Aicken, F. M. Chem. Phys. Chem. 2003, 4, 824-829.
(4) Popelier, P. L. A. Quantum Chemical Topology: on Bonds and Potentials; Springer: Heidelberg, Germany, 2005.
(5) Bader, R. F. W. Atoms in Molecules. A Quantum Theory.; Oxford Univ. Press: Oxford, Great Britain, 1990.
(6) Popelier, P. L. A. Atoms in Molecules. An Introduction.; Pearson Education: London, 2000.

Nonlinear Optical Spectroscopy of Interfaces

Speaker: Dr. Heike Arnolds, Surface Science Research Centre, Department of Chemistry, University of Liverpool.

Vibrational spectroscopy is powerful because intrinsic vibrations of the sample under study provide us with chemical information. It is a challenge to study specifically molecules at an interface, as IR and Raman have limited surface sensitivity, and the response of a minor portion of interfacial molecules may be obscured by the bulk response on either side of the interface. In vibrational Sum Frequency Generation (SFG), two short laser pulses, one in the IR, one in the visible, meet at the interface, which causes emission of light at the sum frequency. The optical selection rules suppress the signal from the isotropic bulk, making it inherently sensitive to the interface and allow determination of the absolute orientation of molecules at interfaces. Additionally, the use of femtosecond laser pulses permits simultaneous time and frequency resolution in order to follow molecular dynamics at interfaces in real time. In this talk I will give an overview of SFG for the study of molecular adsorption and dynamics at interfaces.

Sustainable catalysis

Speaker: Prof Mike North, Department of Chemistry, University of Newcastle

The seminar will be concerned with the use of catalysts derived from abundant metals to catalyse reactions between epoxides and heterocumulenes. In particular, the reaction between epoxides and CO2 leading to commercially important cyclic carbonates will be described. The development of immobilized catalysts which are compatible with waste CO2 in power station flue gas will be discussed, as will the use of other heterocumulenes such as CS2 and isocyanates, leading to a range of 5-membered ring heterocycles.

Forty years of chemistry in 40 minutes

Speaker:  Dr. Chris Newton, BioFocus (Galapagos UK), Saffron Waldon UK

Photoinduced electron transfer dynamics: from simple model systems to complex molecular architectures

Speaker: Prof Eric Vauthey, Department of Physical Chemistry, University of Geneva, Switzerland

Photoinduced electron transfer (PET) reactions play an important role in many areas of chemistry and biology and are involved in several practical applications such as solar energy conversion, and photopolymerization. Despite the numerous studies, important questions still remain unanswered, such as the origin of the unusual driving force dependence of the bimolecular PET rate constant and the nature of the primary reaction product. The first part of the lecture will focus on our recent investigations using femtosecond spectroscopy aiming to answer these basic questions. The second part will be devoted to the excited-state dynamics of multichromophoric compounds able to self-organize in various sophisticated architectures, that can be used to generate photocurrent or transmembrane pH gradient. The various charge transfer processes that are at the origin of these functions will be discussed.

Targeting quadruplex DNA with metal complexes
Speaker: Prof Ramon Vilar, Department of Chemistry, Imperial College, London

Recent bioinformatic studies have established that in the human genome there are ca. 350,000 guanine-rich sequences that can potentially form quadruplex DNA structures. Some of these sequences have been identified as targets for the development of novel anticancer drugs. Over the past few years, we have developed a range of metal complexes with high affinity for quadruplex DNA structures. Some of these molecules have been shown to have potential as either anticancer therapeutics and/or optical probes for cellular imaging. This lecture will discuss our latest results in the area (for a review see: Angew Chem Int Ed, 2010, 49, 4020).

Towards the Creation of Life using Bottom up Evolution: Inorganic Biology

Lee Cronin, WestCHEM, School of Chemistry, University of Glasgow, Glasgow

What is life? How did life start on planet earth 3.5 billion years ago, and which molecules / chemical systems lead to biology? Could evolution be the ultimate creationist? Is there are general theory of evolution that extends to all matter? Can we make or evolve life from scratch in a matter of hours? These are fantastically interesting questions but in this lecture, rather than look back into the past, we will look to the future and discuss how chemists may go about
creating new types of truly synthetic (artificial or inorganic biology). In embarking upon this quest we will be asking the question “What is the minimal chemical system that can undergo Darwinian evolution?” and in doing so looking towards the concept of ‘adaptive matter’ and
evolvable materials and chemical systems. The aim is inorganic biology, or more simply, a living system that does not use the current chemical infrastructure utilized by biology. In approaching
this grand aim I will discuss our attempts to engineer complex chemical systems using inorganic clusters that can exhibit autocatalysis, membrane formation, and chemical oscillations as well as the development of new technologies and chemical networks and new formats for chemical synthesis.

Ultrasonic production of responsive polymer microspheres for targeted delivery

Speaker: - Gareth Price. Department of Chemistry, University of Bath

There is tremendous current interest in developing systems that will deliver drugs or other active molecules to particular sites and release then in response to particular stimuli. In the past, ultrasound has been used to produce micron-sized hollow spheres from proteins. Our interest has been to adapt this technology to use synthetic polymers based around amphi-philic copolymers containing segments that are responsive to pH, temperature or light to make microspheres filled with solutions of dyes or drugs that can be released on demand. The lecture will describe the background methods, the copolymer preparation and demonstrate some potential uses of the materials.