Posts Tagged ‘chemical behaviour’

A short history of molecular modelling: 1860-1890.

Saturday, February 5th, 2011
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In 1953, the model of the DNA molecule led to what has become regarded as the most famous scientific diagram of the 20th century. It had all started 93 years earlier in 1860, at a time when the tetravalency of carbon was only just established (by William Odling) and the concept of atoms as real entities was to remain controversial for another 45 years (for example Faraday, perhaps the most famous scientist alive in 1860 did not believe atoms were real). So the idea of constructing a molecular model from atoms as the basis for understanding chemical behaviour was perhaps bolder than we might think. It is shown below, part of a set built for August Wilhelm von Hofmann as part of the lectures he delivered at the Royal College of Chemistry in London (now Imperial College).

The original August Wilhelm von Hofmann molecular model, located in the archives at the Royal institution, London and used by Hofmann in his 1865 lecture there


On the importance of Digital repositories in Chemistry

Friday, April 3rd, 2009
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The preceeding blog entries contain stories about chemical behaviour. If you have clicked on the diagrams, you may even have gotten a Jmol view of the relevant molecules popping up. But if you are truly curious, you may even have the urge to acquire the relevant 3D information about the molecule, and play with it yourself. Even after 15 years of the  (chemical) Web, this can be distressingly difficult to achieve (or can it be that it is only myself who wishes to view molecules in their  native mode?).  Thus the standard mechanism is to seek out on journal pages that disarming little entry entitled  supporting information and to hope that you might find something useful embedded there.  Embedded is the correct description, since the information is often found within the confines of an Acrobat file, and has to be extracted from there.  Indeed, that is what  I had to resort to in order to write one of the blog entries below. I ground my teeth whilst doing so. 
So is there a better way? We think so! The  digital repository. If you click on this you should see the entry directly. What can you do there? Well, if you have suitable programs, you can download eg a Checkpoint file of the calculation that created the molecule model and re-activate it there. Or you can download just the CML file for viewing in any CML-compliant program (such as e.g. Jmol). Or you can check up on the InCHi string or the InChI Key of the molecule.