NChem Research Highlights: BO, drag and knotty molecules

Put the kettle on, settle down and read our Research Highlights.

The Born-Oppenheimer approximation simplifies the Schrodinger equation into more manageable pieces (unlike physicists, some of us have to deal with more than one electron…) and is pretty crucial for quantum chemistry. It doesn’t always hold, however, but in some complicated physical chemistry we let Gav write about, it still holds up in reactions between hydrogen and chlorine.

Seeing as one day nanoscale people will be driving around in nanoscale cars, it’s worth making sure that they won’t be breaking the 2nd law of thermodynamics. Fortunately for everyone, it doesn’t look like they will: a classical mechanical ratchet on the molecular scale just slows down, rather than going in one direction.

Molecular knots are normally tricky beasts to make – as you might expect – but now a method to make some by simply allowing silver ions and organic ligands to diffuse together takes only one step. Different length ligands produce different knots.

Neil

Neil Withers (Associate Editor, Nature Chemistry)

Reactions – Andrew Wilson

1. What made you want to be a chemist?

I was a reasonable tuba player and had auditions to go to music college – these didn’t go too well and it was pointed out that I was quite good at maths and physical sciences. I thought again and decided that I enjoyed chemistry and was interested in research (whatever that was) so put chemistry down on my university application forms (as well as civil engineering, although I don’t really remember why now). I stumbled into the summer of my second year and found myself in Dave Leigh’s lab (then at UMIST) for a vacation placement and suddenly awoke to the enormous possibilities for making and playing with molecules. I guess that’s when I started to understand what it was I wanted to do.

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

It varies; when the national football team are not doing so well, I want the manager’s job because I haven’t quite grown out of the habit of thinking I know what the best line-up and formation is. On other occasions, I’d quite like to act in West End Musicals as these are the most fantastic live entertainment and encompass acting singing and dancing. Some days, I’d like to be a house husband and stay home with my 1 year old daughter – time spent with her is more rewarding than anything else I do!

3. How can chemists best contribute to the world at large?

Develop the theories, synthetic methodologies and new chemists that permit society to continue to evolve. The scientific aspects cover: preparation/ degradation of recyclable materials, methods for energy collection and storage, purification of the atmosphere/ water and new challenges in healthcare such as an ageing population. I struggle with this one as there are so many fun reasons to do chemistry which we should endeavour to convey to those around us, but some of these issues are pretty big problems – for me it is not really a case of how chemists should contribute, more of what chemists must do or things could get quite sticky!

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

This is not something I think about too often – and now I have, the list gets quite long quickly, not to mention that it’s made me start thinking if I’d prefer to have dinner with someone famous who’s alive. In any event, Leonardo Da Vinci would be quite good – my family were on holiday in Tuscany this summer on a vineyard close to the town where he was born. I was amazed at the diversity of activities he was involved in, particularly some of his engineering work which centuries later seems (to an untrained eye) to be largely unchanged. Tuscany was also very good for food and wine!

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

Today, I ran a couple of TLC’s, an NMR and an IR on a sample so that I had characterization for an undergraduate experiment I have to mark! More seriously, I was still doing a little synthesis last month for a paper that needs finishing off – I should stay away and let my group get on with laboratory work, but even though I don’t have time and I don’t think my group like it too much, I can’t resist the temptation to see if something will work for long.

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

Book: Lord of the Rings because it is good and because it is long, which will be helpful as I’m likely to have plenty of time. CD: Assuming the ready availability of a solar powered CD player; Symphony No. 2 Resurrection by Mahler, but Definitely Maybe by Oasis comes close. Can’t I have a whole i-pod?

Andy Wilson is in the School of Chemistry at the University of Leeds, and works on inhibition of protein-protein interactions, self-assembly and molecular recognition.

Oooh! Aaaah!

Yesterday was the 5th of November, which means thousands — nay millions — of people in the UK spent last night looking up at drizzly skies going ‘Ooooh!’ and ‘Aaaah!’ at successive fireworks. It’s all thanks to a plot 400 years ago to blow up the Houses of Parliament (or is it?)

Now, hands up all the readers whose formative experiences as chemists involve burning things? Thought so — me too! One of my lecturers took this further than most, however, and used to bring home-made gunpowder into lecture theatres to compare to commercial bangers. There wasn’t much sleeping in HIS lectures — or people sitting on the front row.

So, fire, bangs, colours – what more could one want? Think of all that chemistry that’s going on… Thanks to a few excellent websites, I now know that strontium and lithium salts are responsible for red, calcium for orange, sodium for yellow, barium for green, copper for blue and iron is gold (eh?). The crackling showers of white sparks are created by titanium flakes: the noise is caused by the thin layer of oxide cracking as the metal inside melts. Thousands of years since they were first invented, gunpowder is still used to provide both the whizz of the flight and the bang of the subsequent explosion.

All this might seem pretty simple (C + S + KNO3) stuff, but I remember from Dr Ludman’s course just how complicated the reactions were — and how hard to balance in the homework! And all those tightly packed solids give off [relatively] vast volumes of gases in a splurge of energy and entropy.

So the next time you see some fireworks — real or not — spare a thought for the creative chemists with some of the best jobs in the world.

Neil

Neil Withers (Associate Editor, Nature Chemistry)

NChem Research Highlights: layering liquids, double metallocenes and fixing fingerprints

Time for another dose of Research Highlights – we scour the literature so you don’t have to…

First up, would you expect ionic liquids to separate into layers of anions and cations on surfaces? At first glance, you’d probably think they’d mix it around to balance the charge – but not if the surface is charged, as is the case.

Next we have some ‘double metallocenes’ – rather than just one Cp (or indeed Cp*) ring above and below the metal, these have two fused Cp* rings sandwiching two metals. In the 250-word article, I didn’t have space to go into the full story of the magnetic, electronic and redox properties investigated, so you’ll have to go over to JACS for the details.

Serendipity…not just a good name for a cat or a posh word for luck. Where would chemistry be without it? In this case, without a method for ‘fixing’ fingerprints. While trying to make sulfur nitride polymers Paul Kelly and colleagues noticed that the precursor, disulfur dinitride, was so reactive that it was even reacting with the fingerprints on the glassware…and you can imagine the rest!

Neil

Neil Withers (Associate Editor, Nature Chemistry)