IUPAC ’09: Nanofun and marvellous MOFs

I am, like Katharine, attending the 42nd IUPAC General Congress in Glasgow. Chemists from around the globe have descended to discuss chemistry in as broad a sense as possible – there are 20 parallel sessions, and the abstract book weighs 2.4 kg (nearly 5 lb 5 oz for any metricophobes out there). I’m facing a dilemma every session, having to sacrifice 2 or 3 talks that I really want to see! I might do a blog post at the end of the week about the interesting chemistry I DIDN’T have chance to see…

So what have I been doing? After the first plenary (read Phil from Chemistry World’s take on Sir Harry Kroto’s talk here), I went to a session on Adaptive Nanomaterials. It’s interesting to see that in not such a long time, work on nanomaterials has gone from ‘Look, it’s really small!’ to ‘Look, we can sense and discriminate proteins at 5 nanomolar level in a mix of other proteins that are in millimolar concentration!’ And that’s pretty cool. Vince Rotello’s gold nanoparticles need to be functionalised with polymers etc first.

I spent the afternoon hearing about MOFs (metal-organic frameworks). Or are they coordination polymers?? There seems to be a little bit of debate over the matter, but Lee Brammer of Sheffield offered a good distinction: they’re MOFs when they’re open and porous, whereas coordination polymers don’t necessarily have the pores. Anyway, whatever you call them, they were excellent talks about an interesting topic. All of which made me ponder on how the wonderful range of MOFs are all thanks to the quirky nature of transitional metal coordination bonds. Not just tetrahedral for those guys! Eat your heart out carbon [yes, I am inorganic chemist…].

It’s nearly time for day 2 to kick off, so I’m going to head over to the armadillo for Vivian Yam’s plenary.

Neil

Neil Withers (Associate Editor, Nature Chemistry)

IUPAC ’09: Strontium sticks

On my way up to Glasgow from London I did a spot of sailing. On the trip from Fleetwood, Lancashire, to Whitehaven, Cumbria, for a long time we could see the nuclear fuel plant Sellafield. It spans a vast area of the Cumbrian coast line.

So it was with interest that I spotted a poster by phd student Sarah Wallace from Leeds University in the UK.

She has been looking at how strontium, a waste prduct from Sellafield, wil move in the sediment near the plant, and if it might make it into the groundwater.

The contaminant plumes from the plant tend to have a high pH, and what Wallace had found so far is that in these conditions strontium-90 likes to stick to sediment. This could actually be good news for Sellafield because the half life of strontium90 is such that as long as it sticks to the ground it will have decayed within 300 years or so.

Strontium is potentially nasty because it’s in the same chemical group as calcium, a major bone component. So if strontium gets into the water and into the body, it can compete with calcium in the bones and cause diseases such as leukemia.

Wallaces work involved a fake contaminated bit of land – taking normal soil and untouched groundwater from the area and spiking it. In future she hopes to see what the longer term effects of strontium-90 are.

IUPAC ’09: Mapping methanol in space

Who’d have thunk it – a chemistry conference full of space news. It’s not that weird really, when you consider that the search for life = search for molecules.

Lars Kristensen from Leiden University in the Netherlands today showed us his maps of methanol in space. He is making these maps so he can see how methanol is distributed in the material that young stars are made from. Methanol is used as a tracer for early star formation and forms on the surface of interstellar ice-covered dust grains. He’ll also soon be able to compare his methanol maps with results of water abundance from Herschel, which set off recently to check out the most distant objects in the universe.

Methanol forms as ice on dust grains. According to Kristensen, the major way that the methanol escapes from the surface of these grains is not by heating thermally, but by a non-thermal mechanism, be that activation by UV light, or other methods.

The abundance of methanol in the areas that Kristensen looked at, using the Harp B instrument on the James Clerk Maxwell Telescope in Hawaii, was constant throughout those areas, he says.

Check below the fold for one of his maps.

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IUPAC ’09: saving the planet one atom at a time

Hello from Glasgow, Scotland. Home to the deep fried mars bar, Charles Rennie Mackintosh, Gordon Brown MP, and now, for one week only, the IUPAC congress.

I’m here to delve into the finer points of chemistry and to see what is getting chemists salivating this year.

The first session I went to was about artificial photosynthesis. The process that plants carry out with ease – turning sunlight into stored energy – is causing a major headache for scientists trying to mimic the process.

Rather than try to rebuild the molecules used by nature for photosynthesis, chemists are looking at systems that they can build and understand better, and use them to do the same jobs that plants do with their complex molecular machinery.

In these systems, sunlight is used to power the separation of charge – from a neutral molecule to one with a positive and negative component. But the big problem is keeping those charged states apart from one another for any length of time. If they recombine, the charge separation, which could lead to electric current, is lost.

Today I got to see how making the molecules really long with the charged ends separate from each other in space can help. Ken Ghiggino from the University of Melbourne, Australia, uses a set of four porphyrins, which are big ring-shaped molecules. One end has a zinc atom sitting inside the ring and the other a gold atom. These two metals can shunt a charge from one end to the other. The trouble is that this kind of system is far too complicated to ever be manufactured on a large scale.

Another suggestion is simple dyad systems with one charge donating and one charge accepting part. But as Andy Benniston from Newcastle University showed us, to separate the charge with these systems is also not as easy as hoped. He suggested that when previous chemists have claimed to have a long lived charge separated state what they had actually done was form a different quantum state called a triplet state. This is something else entirely.

All this is yet more evidence that nature is unfathomably clever in its use of molecular processes to gain energy, and that humans are way behind in our understanding. But thanks to chemists who refuse to get depressed by this notion, one day we may just be able to take sunlight and produce energy that we can store and use at will, without destroying our world.