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Interview: Making logical connections
01 April 2009
Henry Rzepa tells Carl Saxton about the potential for creativity in both research and teaching activities
|Henry Rzepa is a professor of computational chemistry at Imperial College London, UK. His research focuses on modelling the shapes, properties and reactions of molecules and in presenting this information in internet-friendly ways.|
Why did you decide to become a chemist?
We lived on a farm in Scotland. Once, my mother came down with flu and my father was away. I decided to make my mother a cup of tea. I had only a tenuous grasp of proportions and the resulting brew was close to one part water to 10 parts tea leaves. She drank it nonetheless. Thus encouraged, I starting mixing anything I could find on the farm to see what would happen. By age 14, I had my own laboratory at home. After completing a synthesis of benzidine (nowadays firmly banned as being far too toxic) and reading a textbook on valence theory, the future course of my professional life was firmly set.
What first got you interested in theoretical chemistry?
The textbook on valence theory I allude to above, but more firmly, after completing a Ph.D. in physical organic chemistry and reaction mechanisms. I realised that all those linear free energy relationships I was measuring were not really telling me anything really fundamental about why the molecules I was studying behaved the way they did. I decided that only quantum mechanics was going to do this. At just the right time, Michael Dewar visited the department, and after his inspiring talk, I expressed an interest in working for him. A week later, a package weighing certainly more than a kilogram containing about 50 reprints for me to read arrived. I was hooked!
What projects are you working on at the moment?
One area of research is about unravelling the origins of stereo- and chemoselectivity in metal-catalysed reactions. A good example is rationalisation of the heterotacticity in magnesium-catalysed lactide polymerisation, in terms of how isopropyl groups interact with phenyl faces and other groups.
The second area is the discovery and understanding of new forms of 'chiral aromaticity'. We, and others, have over the last decade shown how some aromaticities can originate from helical (twisted) arrangements of conjugated systems. The first glimmers started some 45 years ago, with the espousal of Mobius molecules by Heilbronner, but it's probably only in the last five years that lots of nice examples of this type of molecule have started to come to light.
The third theme is related to our aim of activating the internet for chemical application.
Well, it will change far more in the next ten years than it has in the previous one hundred. Perhaps the biggest change I foresee is that the readership of the scientific article will not consist of just 'humans', but of what we refer to as 'machines'. The journal article will become semantically enabled, and software agents will be able to assimilate the article logically and infer logical connections to other knowledge. They will distil all this information down to a set of suggestions for the human to make those previously uncharted connections which we call discovery or indeed inspiration. As such, the boundaries and dimensions of what is now a well-defined article will soften and blur.
What are the challenges faced in your research regarding the enhancement of chemical journals?
Chemical journals currently serve as the primary depositories of knowledge about our subject. They also serve the sociological purpose of career advancement and promotion. Changing the very nature of what we now call 'an article' means rethinking how any new entity that emerges can serve these sociological needs. Change is often resisted for such reasons, since the scientists have a need to know how their 'publication metrics' will impact upon their career. There is a hint of 'why should I allow my article to be enhanced, since it is highly likely to assist my greatest rivals rather than my own reputation?' So the greatest challenge to the enhancement of chemical journals is the mindset of the authors themselves.
What is the most difficult problem you've had to overcome?
Scientifically, it must be our understanding of Mobius conjugated molecules, which had a gestation period of around 30 years. For twenty of those years nothing much gelled, and as a result it remained an interesting but unresolved problem. My own breakthrough came with an apparently senseless question asked by a student during an undergraduate lecture on pericyclic reactions. At the time I could offer no cogent answer to the student, but it was enough of a spark to start things flowing. The difficulty was in joining up about 4-5 apparently unrelated concepts from fields outside my normal comfort zones. The expectation is that the semantically enriched journals already noted will augment the impetus imparted by student questions.
You recently published articles in Dalton Transactions and PCCP that contained enhanced tables and figures - how important is it for journals to contain enhanced features?
In my own research, the three-dimensional and stereochemical nature of molecules is always essential for a fundamental understanding of what is happening. This means providing other scientists with three-dimensional molecular coordinates (these served Watson and Crick rather well for example). In 1994, it struck me that an obscure system known as the 'Web' might serve this purpose. I and colleagues put some ideas together and published a Chemical Communication setting out a vision for the future. This communication made the broader point of course that to truly understand a chemical phenomenon, you benefit from having the data that constitutes the model being presented. With that first article, we proposed our data-model of the future journal article. That is the true enhancement, not merely the visual element of rotating molecules. Nowadays, we use a combination of digital repositories to store the original research data, linked to enhanced features of journal articles.
If I say it is ahead of its time, you must understand that I view it as very much central to our vision of the future. It is part of that semantically enabled vision I spoke about earlier. Currently, Prospect is still aimed squarely at human readers. But it's just a small step away from the full machine-human symbiosis that I mentioned before. If only all publishers were so innovative.
You have been active in teaching for 31 years - how has the face of teaching changed?
Well, in many ways, students are still students! The very best were capable of astounding me 31 years ago with their enthusiasm and ability, and that still happens to this day. The current school system is so target-driven and students come to us capable of achieving the targets set for them by teachers. It takes a while for them to realise that they now have to set their own targets, and seek out their own feedback. Observing how many students manage the transition from school to being able to cope with the real world in the four years they spend at university is one of the rewards of my job.
The students certainly appreciate being able to replay lectures (in audio), and the enhanced visuals that podcasts can deliver. In one year, my podcasts made it into the iTunes top ten charts! However, preparing podcasts is very time-consuming, and only one other colleague has thus far tried it. So to some extent, we have really not achieved the critical mass of podcast materials in chemistry that would make the genre mainstream rather than just an oddity.
How well do wikis work for teaching undergraduates?
We introduced them about three years ago as part of a chemical information course. Each student had to create a page about a topical or interesting molecule as their course project. It proved very popular, with some students working on as many as six different pages concurrently. We have recently extended this to a molecular modelling course, where the students again document their work, but rather than submitting conventional static images of their work, they integrate 3D coordinates, and properties such as vibrations and molecular orbitals. In effect, they are creating something akin to enhanced journals.
What do you do in your spare time?
My wife and I take the motorbike out, and explore all the rivers, brooks, streams and rivulets of the greater London area (by which I mean we walk the rivers, but get there by bike!) and chart our walks using Google Earth and 'geo-tagged' photos. I am also an avid (season ticket rather than armchair) football supporter. Music is also very important. Sibelius reminds me of my childhood in Scotland, and I just love sitting through six hours of Wagner!
If you weren't a scientist, what would you be?
Were it not for my total lack of any skills, I would have enjoyed being a composer.
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Henry Rzepa's homepage
at Imperial College, London, UK
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Chemical applications of the World-Wide-Web system
Henry S. Rzepa, Benjamin J. Whitaker and Mark J. Winter, J. Chem. Soc., Chem. Commun., 1994, 1907
A computational investigation of the structure of polythiocyanogen
Charlotte S. M. Allan and Henry S. Rzepa, Dalton Trans., 2008, 6925
Wormholes in chemical space connecting torus knot and torus link -electron density topologies
Henry S. Rzepa, Phys. Chem. Chem. Phys., 2009, 11, 1340
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