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Yttrium ferricyanide

20 January 2016 - Chemical Zoo

yttrium ferricyanide duyker 2016.PNGIn the chemical zoo this week: yttrium ferricyanide YFe(CN)6. Otherwise a truly unremarkable compound but for one property: its compressibility. Duyker et al. report about it in Nature Chemistry (DOI). Measuring it is one thing: 25% at 1.5 Gpa - by neutron powder diffraction - but figuring out how exactly the crystalline material compresses is another. Regular solid caesium has a similar compressibility but entirely on account of reduced bond lengths. In Yttrium ferricyanide it is expected that actual bond distortion is involved but which ones? The material is a coordination framework akin a MOF with octahedral FeC6 units in a hexagonal superstructure with trigonal prismatic YN6 units. It turns out the FeC6 units are very rigid and that the YN6 units do all the work: they go from trigonal to octahedral and the linear Y-N-C-Fe bonds get seriously bent. In fact the bending motion costs energy but the twisting of the YN6 unit is energetically favourable, the unit is compared to a pre-wound mainspring. Watch the movie!


Clean that NMR tube

17 January 2016 - Laboratory procedures

klik hier voor de afbeelding op ware grootteSome practical advice from Thanh Binh Nguyen in the latest issue of OPR&D: a novel way to clean NMR tubes! (DOI). This being a long-outstanding challenge in laboratories all over the world you might be interested. The method requires a vacuum desiccator and a beaker and nothing else. It is advertised as an affordable method and one that allows bulk processing. With the tubes placed upside-down in a beaker containing a cleaning solvent, the bottom line is that in successive vacuum cycles solvent enters and exits the tubes.

This communication surely was swift! Received January 1 2016 and published on-line January 6! Glad to note that at least some people regard the first day of a year a regular working day. At a minimum you still have to push the "send email" button. The article is unique in another way: just one page with just one reference! Can we have more of those?


Ecstasy in your next meal

10 January 2016 - Sensational headlines

In The Netherlands the curse of the illegal drug laboratories continues (earlier episode here). Latest development: the chemical waste associated with it may end up in my next meal (NOS scoop here). How? Even though there are no signs that illegal drug production is diminishing (despite law enforcement efforts) the amounts of chemical waste certainly do. The all-time favourite place for the drug lords to dump chemical waste in is a nature reserve and the authorities used to be very busy cleaning up after them but not any more. Have the laboratories finally learned how to manage their waste in a responsible way? Have the drug lords been investing in new atom-economic chemistries or do they recycle? No, they have got a bit smarter than that. A recent illegal drug lab case in the Dutch town of Someren suggests they have found a novel form of waste disposal. The lab was discovered on a farm, chemical waste was found to have been dumped in the slurry pit and then the liquid manure was found to have been spread across a field that was later planted with maize. This maize (quarantined) now contains verifiable amounts of ecstasy. This is fortunately where the food-chain contamination ended in this business case. We did not get to the mad-pigs-on-ecstasy stage (let alone ecstasy in my pork chops) but it is annoying anyway.
From a physical chemistry point of view it remains to be seen if the new method is going to be adopted on a large scale. I know what liquid manure looks like and from what I now of typical chemical waste in the laboratory the two may not mix that well. Without getting specific on the type of farm equipment used, a good mix is what you need. The guy who should have the details - the farmer - has vanished. taking all the accumulated know-how with him.


Elsewhere on the Net

09 January 2016 - The Blogs

One year ago this blog featured the segment Elsewhere On The Internet and again this year we have a look at other blogs happening around the world.

Lamentations on Chemistry discusses the hidden dangers of cleaning up magnesium. Another warning is from In The Pipeline on a recent incident with trimetylalumium. But what is Donald Trump doing in the comments section? For serious synthetic chemistry visit Interesting Organic Chemistry. For practical chemistry: MJLPHD produces of cypress oil, Chempics explains everything about cinnamon and My Passion For Inorganic Chemistry demonstrates 5 ways to synthesise oxygen in a smart video. The blog's owner is Shiva and his neighbours will be unhappy to learn the entire thing was filmed at his home! Read FX's blog for the curse of coercive citations. In OpenFlask the Baran lab has the behind-the-scenes on the antroquinol story. Regarding All Things Metathesis, is it possible to devote an entire blog to a single type of organic reaction? Yes.

Mass-spectroscopy enthusiasts go to Practical Fragments. The Curious Wavefunction asks itself if chemistry is a true science. After all synthetic chemists shun hypotheses and never falsify. Henry Rzepa in 2016 continues on a project (diazo coupling) he started in 1972. That is perseverance. More on azo systems in Computational Organic Chemistry. The Chemical Blog is building Minecraft molecules Just Like Cooking while digging around in ancient literature came across a chemical reaction procedure that involved heating up stuff to 450°C! By big coincidence OrgPrepDaily recently managed to ruin a flask in a similar high temperature experiment

Adrian Dingle's Chemistry Pages has the news on the new elements confirmed in the Periodic Table and announces the hunt for element 119, also table related The Chronicle Flask urges everyone to sign the petition for octarine as the new official name for element number 117, CompoundInterest also speculates on what the official names the new elements will eventually end up having. Apparently a competing petition exists for Lemmium!