Sunday, 30 June 2013

#chemclub Roundup 12

Once again, here's a roundup of the best of the #chemclub Twitter feed from the last two weeks. (Confused? Read this.) The second review will go online early in this week; this unfortunately coincides with the death of Google Reader tomorrow. If somehow you both use this reader and live under a rock, you may need a replacement; personally I'm using Feedly, which now has a pretty green button on this page.

On the blogs, Derek Lowe discusses Collins & Glorius' proposed robustness screen (mentioned here last week); BRSM talks us through Evans' recent synthesis of nakadomarin A; and John of It's The Rheo Thing discusses the unusual world of metallocene polymers.

First up, four papers from Angew. Chem. I particularly enjoyed the first two, which concern some really fundamental chemistry and should interest pretty much anyone.

The first paper was popular, and rightly so. It concerns the unusually low melting point of mercury, which has long been attributed to relativistic effects due to the presence of relativistic effects in group 11/12 metals (such as the colour of gold). Evidently this explanation has been, until now, largely hand-wavy, and this paper represents the first direct evidence for it. The authors used Monte Carlo simulations with and without factoring in special relativity to demonstrate that relativistic effects dramatically lower mercury's melting point.
A second paper looks at some more fundamentals, namely the deposition of cations at surfaces. It's nicely-written, concise, and accessible, with an enjoyable discussion of the history of the subject. Definitely worth reading this! Not sure what it has to do with barbarians, though.
Moving away from theory into applications, Padial et al. describe metal-organic frameworks functionalised with CF3 groups and their ability to absorb pollutants and chemical weapons under challenging conditions. It's a thorough study of the effect of the structure of the MOFs on their function.

The final paper from Angew. Chem. expands the reactivity of alkyl azides to C-H activation at arenes through Rh catalysis. The reaction produces amines ortho to benzamides, aryl ketones and aryl ketoximes. There's mechanistic study and it generally seems like solid work.

Finally, a paper from that small subset of journals that aren't called Angew. Chem.! In Nature Chemistry, Lee et al. report the synthesis of a novel macrocycle called cyanostar. It's remarkable for two reasons: it can be synthesised readily on multigram (~9 g) scale, and it binds to large, weakly-coordinating anions such as BF4- and PF6-. This affinity is used to form rotaxanes with phosphate templates.

1 comment:

  1. "enigma of metal deposition" vs "riddle of steel" is the conan connection. i'm not sure it was intentional, myself

    the riddle of steel -

    i guess these tweets were supposed to get me to read these papers, but now im just gonna watch conan the barbarian again instead