Archive for April, 2020

A databank of molecular dynamics reaction trajectories (DDT) focused on undergraduate teaching.

Wednesday, April 22nd, 2020

In a previous post, I talked about a library of reaction pathway intrinsic reaction coordinates (IRCs) containing 115 examples of organic and organometallic reactions. Now (thanks Dean!) I have been alerted to a brand new databank of dynamics trajectories (DDT), with the focus on those reactions taught in undergraduate organic chemistry courses, some of which are shown below.

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A molecular sponge for hydrogen storage- the future for road transport?

Sunday, April 19th, 2020

In the news this week is a report of a molecule whose crystal lattice is capable of both storing and releasing large amounts of hydrogen gas at modest pressures and temperatures. Thus “NU-1501-Al” can absorb 14 weight% of hydrogen. To power a low-polluting car with a 500 km range, about 4-5 kg of hydrogen gas would be need to be stored and released safely. The molecule is of interest since it opens a systematic strategy of synthetically driven optimisation towards a viable ultra-porous storage material,[1] much like a lead drug compound can be optimised.

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References

  1. Z. Chen, P. Li, R. Anderson, X. Wang, X. Zhang, L. Robison, L.R. Redfern, S. Moribe, T. Islamoglu, D.A. Gómez-Gualdrón, T. Yildirim, J.F. Stoddart, and O.K. Farha, "Balancing volumetric and gravimetric uptake in highly porous materials for clean energy", Science, vol. 368, pp. 297-303, 2020. http://dx.doi.org/10.1126/science.aaz8881

Choreographing a chemical ballet: a story of the mechanism of 1,4-Michael addition.

Monday, April 13th, 2020

A reaction can be thought of as molecular dancers performing moves. A choreographer is needed to organise the performance into the ballet that is a reaction mechanism. Here I explore another facet of the Michael addition of a nucleophile to a conjugated carbonyl compound. The performers this time are p-toluene thiol playing the role of nucleophile, adding to but-2-enal (green) acting as the electrophile and with either water or ammonia serving the role of a catalytic base to help things along.

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A cascading tutorial in finding rich NMR data using the Datacite datasearch engine.

Saturday, April 11th, 2020

In the previous post, I introduced three of a new generation of search engines specialising in the discovery of data. Data has some special features which make its properties slightly different from the conceptual (or natural language) searches we are used to performing for general information and so a search engine specifically for data is invariably going to reflect this. At the simplest level, the data search can retain much of the generic simplicity of a regular search, but to exploit the unique features of data, one really does have to move on to an advanced mode. Here, by introducing a set of search definitions that gradually increase in specificity and power, I hope to convey some of the flavour of one way in which this could be done.

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New generations of globally aggregating search engines – for (chemical) data.

Tuesday, April 7th, 2020

Chemists have long been familiar with search engines that aspire to index a large proportion of the chemical literature. Think for example the old-generation (and commercial) SciFinder (Scholar) and Reaxys or those that arrived in the 1990s in the online era such as the non-commercial Pubchem or ChemSpider (there are more). But you may not be as familiar with the latest generation of global search engines and here I will focus on three relatively new ones that specialise specifically in tracking down data rather than just publications.

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