Posts Tagged ‘energy difference’

Molecule orbitals as indicators of reactivity: bromoallene.

Thursday, September 1st, 2016
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Bromoallene is a pretty simple molecule, with two non-equivalent double bonds. How might it react with an electrophile, say dimethyldioxirane (DMDO) to form an epoxide?[1] Here I explore the difference between two different and very simple approaches to predicting its reactivity. bromoallene

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References

  1. D. Christopher Braddock, A. Mahtey, H.S. Rzepa, and A.J.P. White, "Stable bromoallene oxides", Chem. Commun., vol. 52, pp. 11219-11222, 2016. http://dx.doi.org/10.1039/C6CC06395K

Bond stretch isomerism. Did this idea first surface 100 years ago?

Tuesday, February 9th, 2016
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The phenomenon of bond stretch isomerism, two isomers of a compound differing predominantly in just one bond length, is one of those chemical concepts that wax and occasionally wane.[1] Here I explore such isomerism for the elements Ge, Sn and Pb.

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References

  1. J.A. Labinger, "Bond-stretch isomerism: a case study of a quiet controversy", Comptes Rendus Chimie, vol. 5, pp. 235-244, 2002. http://dx.doi.org/10.1016/S1631-0748(02)01380-2

Oxime formation from hydroxylamine and ketone: a (computational) reality check on stage one of the mechanism.

Sunday, September 23rd, 2012
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The mechanism of forming an oxime from nucleophilic addition of a hydroxylamine to a ketone is taught early on in most courses of organic chemistry. Here I subject the first step of this reaction to form a tetrahedral intermediate to quantum mechanical scrutiny.

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Driving the smallest car ever made: a chemical perspective.

Thursday, November 10th, 2011
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Fascination with nano-objects, molecules which resemble every day devices, is increasing. Thus the world’s smallest car has just been built[1]. The mechanics of such a device can often be understood in terms of chemical concepts taught to most students. So I thought I would have a go at this one!

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References

  1. T. Kudernac, N. Ruangsupapichat, M. Parschau, B. Maciá, N. Katsonis, S.R. Harutyunyan, K. Ernst, and B.L. Feringa, "Electrically driven directional motion of a four-wheeled molecule on a metal surface", Nature, vol. 479, pp. 208-211, 2011. http://dx.doi.org/10.1038/nature10587