Archive by category | Anne Pichon

Ambiguous bromine

At first sight bromine seems to be ‘just another halogen’, a helpful counter-anion or leaving group in SN2 or cross-coupling reactions. Of course this isn’t the whole story, as Matt Rattley — a chemistry student at the University of Oxford and the author of the winning essay on bromine for last year’s contest — points out in his article (subscription required).  Read more

The four worlds of carbon

The four worlds of carbon

Our element of the month is carbon. Carbon is so ubiquitous, with its various allotropes and as part of the many, many compounds and living organisms it makes up, that it’s hard to know where to start. Well, why not in New York City? As Simon Friedman from the University of Missouri Kansas City — interviewed here in Reactions — puts it in his article (subscription required) “The organic chemist’s view of carbon can be like the New Yorker’s view of the world, which to them ends at the edge of Manhattan.” And so he goes on to explain.  Read more

DNA nanotechnology workshop: Unnatural assemblies

I’m just back from Shanghai, where I attended the 2nd DNA nanotechnology workshop, a very exciting meeting at which we also celebrated the prestigious Albert Einstein professorship of the Chinese Academy of Sciences being awarded to Ned Seeman, often called ‘the father of DNA nanotechnology’. The story goes that as a young crystallographer, worried about getting tenure, he went to the campus bar to have a few beers and mull things over. Seeman found inspiration in the Escher woodcut Depth to make crystals using DNA, so as to avoid the guessing game (and potentially praying)­ that everyone who ever tried to crystallize anything is only too familiar with. The rest, as they say, is DNA nanotechnology.  Read more

Element of the month: Cool as helium

This month’s ‘in your element’ article (subscription required) is also a winning entry from last year’s competition. Christine Herman, known on Twitter at @CTHerman, a PhD student at the Department of Chemistry, University of Illinois at Urbana-Champaign, who also likes to write about science — for example she contributes to C&En’s Just Another Electron Pusher — shares why she loves helium.  Read more

Element of (last) month: A pinch of sodium

In the midst of the blog relaunch, a trip to China last December (which I plan on telling you about in a future post), and the end-of-year holiday period followed by a start-of-year busy period, I didn’t get the chance to write about our December in your element article. This is the first competition winning essay that we’ve published — I think I did mention last year’s essay competition a couple of times.  Read more

Element of the month: Oxygen origins

Oxygen is everywhere. Really, few elements are more abundant in the universe — in fact just two, hydrogen and helium. It combines with most other elements from the periodic table to form an incredibly wide range of compounds which serve an incredibly wide range of purposes. Just looking at the Earth: oxygen-bearing compounds are found in the mantle, crust, oceans and seas, atmosphere and living organisms, not to mention natural and man-made materials such as silica, zeolites, textiles, ceramics and drugs. Oh, and oxygen also takes part in energy production, as well as a variety of processes that range from metabolic to geological.  Read more

ICCOSS XX: Growing crystals in all shapes -and sizes

All good things come to an end… Among the many, and varied, aspects discussed at ICCOSS over the past few days, I wanted to bring your attention to halogen–halogen bonding, which seems to be becoming quite popular. When a halogen atom engages in such a bond, its charge distribution changes a little, leading to a ‘polar flattening’ of the atom. The more electronegative side of one atom naturally engages in a halogen–halogen bond with what has become the more electropositive side of the other. Can these interactions be relied on to assemble building blocks? Can they be tuned in a controllable manner by judicious choice of the halogen?  Read more

Pacifichem 2010: Dispersion corrections and gelation

This morning I went to some physical chemistry sessions on computational quantum chemistry. I won’t attempt to summarize the various interesting points raised by the speakers as well as the members of the audience, but I’d like to highlight one conclusion from Stefan Grimme’s presentation: he showed that dispersion corrections should really be used routinely – rather than occasionally – in density functional theory (DFT) methods. Pavel Hobza, who next took the stage, wholeheartedly agreed, saying in particular that these corrections play an extremely important role when it comes to biomolecules.  Read more

Pacifichem 2010: Variety is the spice of life

This past couple of days I have been attending more traditional, ‘core’ areas of chemistry at the inorganic, macromolecular and organic sessions. I first went to “the new age of advanced materials” symposium, and although I was fighting a little bit of jet lag and sleep deprivation (not a good combination) it made for a very interesting morning. Among exciting endeavours on helicity, supramolecular chirality, and controlled assembly and organization, Sam Stupp from Northwestern University showed interesting bioapplications with his supramolecular polymers, such as some neurotherapy studies that look promising against Parkinson’s disease.  Read more