Monthly Archives: August 2010

EuCheMS – Elemental enjoyment

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If yesterday’s blog themes were mechanisms and energy, then today’s theme is elements. Different, diverse elements. (It does occur to me that, as pretty much all chemistry is concerned with one element or another, this isn’t really much of a theme!) I pretty much stuck to the Advances in Organic and Inorganic Chemistry part of the programme today, which was focused on Advances in Inorganic Synthesis.

Matthias Driess kicked things off by discussing transparent conducting oxides (TCO). These materials are incredibly widely used in display technologies and it’s this wide use that is the problem: the world is running out of indium, the major part of the most common TCO, indium tin oxide (ITO). So much so that, according to Driess, the price of indium is increasing by 120% – per year! Ouch. Increasing the amount of tin would help to reduce that need, but above a certain level this renders the material much less useful. Fortunately for everyone, Driess and his group have developed a way to make a tin-rich ITO using a molecular precursor whose structure mimics the final solid.

So that’s the main block ticked off the periodic table. Next up Rhett Kempe talked about compounds with metal-metal bonding, a field which has expanded quite a lot in the past 10 years. He’s been trying to make compounds with lanthanide metal atoms solely coordinated to transition metals – and you can read about it in the pages of a certain chemistry journal you may have heard of… Kempe hopes these will bridge the gap between bimetallic complexes and intermetallics.

What’s left on my tour of the periodic table? Ah yes – the actinides. Fortunately, I only had to wait until after lunch to tick these off! Geoff Cloke gave a great talk outlining his group’s work looking at transformations of ‘carbon oxides’ with uranium(III) sandwich compounds. Starting from carbon monoxide at low temperature they’ve been able to generate linear, ‘deltate’ (triangular), ‘squarate’ and zig-zag species between their sandwiches. Some of these – particularly the zig-zag – can then react with hydrogen and produce alkanes. Which is roughly what Fischer-Tropsch catalysts, only these reactions are carried out at -80 °C!

I’ll leave it there for my whirlwind tour of the elements, but leave you envious in the knowledge that the conference bag contained a periodic table fridge magnet! Which, I’m ashamed/proud to admit, is actually now the second one that I own…

Neil

Neil Withers (Associate Editor, Nature Chemistry)

EuCheMS – Mechanistically minded

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Greetings from rainy sunny rainy confused Nuremberg Nürnberg, where I am attending the 3rd EuCheMS meeting. As ChemCafé’s Sebastien Rochat tells us, this is the ‘unpronounceable acronym for European Association for Chemical and Molecular Sciences’. Unfortunately, I arrived even later than Sebastien and thus missed the welcoming speeches, first two plenaries and the reception. Thanks to Air Berlin for that!

EuCheMS is one of those biggish, but not ACS-big, meetings: 7 parallel sessions in a congress centre where you can actually get between rooms relatively quickly and even bump into people you didn’t know were attending. I had planned to spend the day flitting between the ‘Resources and Environment’ and ‘Advances in Organic and Inorganic Chemistry’ sessions, but ended up sticking mainly to the latter, with an unplanned excursion into the ‘Innovative Materials’ programme.

But my thirst for energy chemistry was slaked early on – Michael Grätzel from EPFL gave today’s first plenary on ‘Molecular photovoltaics’. As you can probably imagine, this was a great talk from the guy who invented dye-sensitised solar cells. If you can’t imagine, go and read the Wikipedia page! His obvious excitement came through as he showed picture of some of the applications that they’re starting to find – my favourites were the DSSC walkman (being developed by Sony) and sunglasses. Another highlight was his description of getting schoolchildren to isolate anthocynanine dyes from blackberries to use – and getting a 600 mV output!

My two other highlights from today shared a mechanistic theme. Both Odile Eisenstein and Guy Lloyd-Jones are interested in getting to the bottom of why some catalysts/ligand combinations are better than others. But Eisenstein uses computations guided by experiments while Lloyd-Jones uses experiments guided by computations. Eisenstein’s talk on metathesis chemistry, and the importance of the coordination of the alkene to the metal centre, and Lloyd-Jones’ on palladium-catalysed biaryl couplings, showed that optimisation might not just be a case of slogging through reactions, but can be guided by insights.

Finally, if you’re reading from EuCheMS, do drop by our stand (booth 27) in the expo to spin the ‘wheel of fortune’ to win a range of prizes! Anything from pens to journal subscriptions to a Flip Video.

Neil

Neil Withers (Associate Editor, Nature Chemistry)

Reactions – Christopher Cahill

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Christopher L. Cahill is in the Department of Chemistry at the George Washington University in Washington, DC, where he works on uranium containing materials.

1. What made you want to be a chemist?

This may be a disappointing answer, yet I never ‘wanted’ to be a chemist. Rather, I just kind of fell into it. I went to college to be a music major and very quickly learned that being the hot-shot in the high school band did not translate to having any real talent. I had my first advising session with a ‘default’ advisor who happened to be a Chemistry professor. He suggested I take General Chem just to get on a science track in case the whole music thing didn’t work out – very perceptive! I pursued a geochemistry degree and became enamored with natural systems, particularly minerals.

2. If you weren’t a chemist and could do any other job, what would it be – and why?

This is a tough one. Fantasy answer: drummer in a rock band – big time. Plausible answer: economist. I am intrigued by global scale ‘cause and effect’ scenarios and love traveling to exotic locations. If, on the other hand, I had the attention span, patience (and an alternate source of income), I’d return to my family’s apple orchard.

3. What are you working on now, and where do you hope it will lead?

Synthesis, reactivity and spectroscopy of uranium containing materials. I am very much interested in the environmental impact of the nuclear fuel cycle. We are headed for a renaissance of nuclear power and we need to address some tough issues regarding waste stewardship, reactor design and non-proliferation of weapons capable material. Beyond the experimental science, some colleagues and I are hard at work on curriculum development here at GW to bring policy people and scientists together. We are developing lab courses for the non-scientists and policy courses for the scientists. Policy (and often not science) is at the center of most decisions regarding nuclear issues. We need both camps to be ready. I hope these efforts lead to an educated workforce and a solid body of knowledge to allow for unbiased, fact based decision making at all levels.

4. Which historical figure would you most like to have dinner with – and why?

Thomas Jefferson. I have always been fascinated by this guy – a real polymath, and you know the wine would be good. I would want to know more about the birth of a nation and his interest in agriculture and starting vineyards in America. His views on the dissemination of knowledge are timeless. I would call him out however, on his take on gender/race inequality (after eating, of course).

5. When was the last time you did an experiment in the lab – and what was it?

This week – a single crystal structure determination of a uranyl tetrachloride compound. These days, most of my experimental work is crystallographic in nature. I am afraid I haven’t dirtied a beaker in some time.

6. If exiled on a desert island, what one book and one music album would you take with you?

The music album response is a no-brainer: “The Last Waltz” by The Band. The version of “The Weight” featuring The Staples Singers is the most profound piece of rock music ever performed. In fact, I have the DVD of this concern which we use as mandatory viewing at research group parties at my house.

As for the book, this is tough. Assuming there is no Fodor’s “Desert Islands on $50 a Day”, I’ll take a “Prayer for Owen Meany” by John Irving.

7. Which chemist would you like to see interviewed on Reactions – and why?

I assume an impossible reply is acceptable? So – Joseph Priestley! I am fascinated by figures who are experts/versed in a range of subjects and who work (struggle?) to reconcile faith with science. This answer may be subconsciously related to my desire to have dinner with Thomas Jefferson. Specifically, I’d want to know why he held on to phlogiston so long, how he feels about being credited with founding Unitarianism and if he wished he’d kept a lower profile regarding the French Revolution.

ACS:…and Villains?

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So the theme of my meeting continues.

Yesterday, I spent much of the day in the Robert Burns Woodward (RBW) memorial symposium. The talks were from those who have previously worked with RBW with a particular emphasis on how his philosophy has affected their own research. It’s tough to imagine what modern organic chemistry would be without him.

One talk in particular stood out and – from the number of attendees – not just for me either: Jeffrey Seeman’s ‘Was plagiarism involved in the development of the Woodward-Hoffmann rules?’. It’s not hard to imagine why…as Seeman pointed out, this is probably the first time the word plagiarism has appeared in the title of a talk at the ACS!

A little background for the uninitiated. The Woodward-Hoffmann rules explain the stereoselectivity of electrocyclisation reactions. The name of the rules is derived from the two chemists who first explained the observed reactivity patterns in the literature. Hoffmann received a share of the 1981 Nobel prize in Chemistry (Woodward would likely have received a second Nobel prize but had died two years previously). But, in 2004 Elias Corey – also by that time a Nobel laureate – claimed that he had provided RBW with the initial idea.

The presentation was fascinating – Seeman has analyzed personal letters and notebooks from Woodward, Hoffmann and Corey, and spoken at some length with Roald Hoffmann. I simply cannot provide the full details here so anyone interested should look out for Seeman’s (future) publication of this analysis – he says he’d like it to be an article but it will probably be a book – either way it should make excellent reading.

The main conclusion, however, was that we can’t know for sure what happened. Only two people really know, and one of them is no longer with us. Seeman says that he feels Corey is recalling the events exactly as he remembers them. Hoffmann for his part had asked Woodward at the time if Corey was involved and the answer was a very clear ‘No’. From a man known for meticulously assigning credit in his other work, it seems unlikely that he acted differently here.

The more important point to take away from this session though is to be very careful when assigning credit. It’s certainly an very emotional issue – even for three people who will remain as heroes of chemistry whatever the truth in this particular case.

Steve

Stephen Davey (Associate Editor, Nature Chemistry)

ACS: Heroes…

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I don’t attend too many press conferences at the ACS meeting – because they are aimed at a much more general audience than a chemistry journal editor (that’s not a bad thing – read on). On Sunday, however, I attended a press conference with the intriguing title of ‘New Heroes of Chemistry’. I really had no idea what this was about as I didn’t read the press release in advance.

From the ACS Portal:

Since 1996, the ACS Heroes of Chemistry program has recognized chemical scientists whose work in various fields of chemistry and chemical engineering has led to the successful innovation and development of commercial products based on chemistry. The Heroes of Chemistry program highlights the vital role of industrial chemical scientists and their companies in improving human welfare through successful commercial innovations and products. It presents an ideal opportunity to enhance the public image of the chemical and allied industries.

During the press conference, the ACS announced the induction of five new ‘Heroes of Chemistry’. Jotham Coe and Brian O’Neill (Pfizer) were involved in the development of a smoking cessation drug – Chantix (varenicline)– Joseph Armstrong III, Ann Weber and Nancy Thornberry (Merck) worked on a Diabetes drug – Januvia (sitagliptin).

The passion of these chemists for their work was clear to see – not least when Coe described how he had seen several close family members suffer and ultimately die from smoking related diseases. As we discussed in our September editorial, chemistry needs a few more champions (or heroes) and I really hope this kind of thing can help. And the best thing is that with this ‘hall of fame’ I don’t think there is any danger of the members later being accused of taking steroids to help get them there!

Incidentally, if you’re at the ACS meeting and want to read our September editorial – and the rest of the issue for that matter – why not pick up a complimentary copy from the expo (Booth 609).

Steve

Stephen Davey (Associate Editor, Nature Chemistry)

Home sweet homepage

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[This post is based on the editorial in the September issue — the full text can be accessed here, available for free to all registered users. We welcome feedback on our editorials in the comments section below.]

The importance of an up-to-date and easy to find website should not be underestimated

Scientists are busy people. On any given day, it is unlikely that the item at the top of a researcher’s to-do list is ‘update website’. Nevertheless, an effective homepage for either an individual researcher or an entire research group may well represent good value for relatively little effort.

Scientists traditionally communicate their research findings to the wider community in one of two ways. Results are typically shared in seminars or conference presentations and, somewhat more formally, through papers published in scientific journals (or deposited in repository websites such as arXiv.org or Nature Precedings).

A well-constructed personal website, however, gives scientists a customizable platform on which useful background information about their research can be presented to a more general audience — as well as offering more technical detail that may be of interest to fellow specialists. Research-group pages can also allow the personality of the group to shine through, reminding us that, for the most part, chemists are human after all!

From the perspective of journal editors who spend a significant amount of time browsing chemists’ websites from around the world, there are certainly some elements that are particularly useful. Obviously contact details are important, but so are summaries of research interests as well as lists of representative publications. And it may not be for the camera shy, but a photo is also quite useful because then we know who to look for if we arrange a meeting at a conference! Perhaps the most important aspect of any website, however, is how long ago it was last updated. Broken links and outdated information are no good for anyone.

Of course, establishing a web presence requires the investment of resources (including time and/or money), but once there, maintenance should be a much less demanding task. And this is just the beginning; the internet can do so much more for chemists, and one example of this can be found at Jean-Claude Bradley’s Useful Chemistry site and associated wiki. It is fascinating to compare these endeavours to the pioneering days of chemistry early in the web’s history.

Beyond personal homepages, the current state of affairs with university homepages has also recently been illustrated by an xkcd comic strip. It’s only funny because it’s true… The cartoon, which highlights the discrepancy between the information presented and what people actually look for, seems to have struck a chord with many university students and staff. It has attracted some attention on Twitter, and even inspired a news piece at Inside Higher Ed, which mentions that some web administrators are already taking it into account for their university homepages’ redesigns.

ACS: Trifluoro talks

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The skies are leaden and we’re set for several days of rain. But the weather isn’t going to deter the thousands of chemists who’ve congregated here in Boston for this fall’s national ACS meeting. The technical program is particularly good this time round, so I’ve had some difficulty cherry-picking which seminars to attend.

I decided to kick off first thing on Sunday morning with an organic symposium held in memory of Keith Fagnou, who tragically died last year. Although the mood was inevitably somewhat sombre, the overall feeling was of a celebration of the chemistry that Keith loved. Indeed, much of the research discussed during the symposium had been influence by Keith’s work.

One theme that emerged was fluorination chemistry, an area that has seen some exciting developments recently – perhaps most notably with Steve Buchwald’s terrific paper in Science (see the abstract here) describing a catalytic cross-coupling process for attaching trifluoromethyl groups to aromatics. But Buchwald’s group is far from the only one developing this kind of reaction. John Hartwig described his work on the use of copper phenanthroline complexes for trifluoromethylation reactions. Although his reactions are currently stoichiometric, he pointed out that both the metal and the ligands are dirt cheap. The complexes can now be generated in situ in reactions, so I’ll watch with interest to see whether a catalytic version is forthcoming.

Melanie Sanford followed this up with two takes on the trifluoromethylation problem. Her first approach involves attaching perfluorinated alkyl radicals to aromatics. Although this works well for perfluorohexyl groups, currently it’s not so good for trifluoromethyl groups – but she’s confident that they’ll be able to optimize the trifluoromethylation reactions. Her second strategy is to use trifluoromethyl cations in cross-coupling reactions. The chief hurdle here is generating a catalytic cycle that has a high turnover number. Her group has now identified a catalytically competent, monomeric palladium(IV) compound for these reactions, a breakthrough that she hopes will overcome the turnover problem.

There’s lots more great chemistry on offer this week, so finding time to blog is difficult – but watch this space!

Andy

Andrew Mitchinson (Senior Editor, Nature)