Archive for the ‘Historical’ Category

Blasts from the past: a snapshot of online content in chemistry, ~1994-1998.

Monday, September 28th, 2020

With universities around the world having to very rapidly transition to blended learning (a mixture of virtual and face-2-face experiences) with a very large component based on online materials, I thought it might be interesting to try to give one snapshot of when the online experience started to happen in chemistry.

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The (+) in D-(+)-glyceraldehyde means it has a positive optical rotation? Wrong!

Friday, December 6th, 2019

Text books often show the following diagram, famously consolidated over many years by Emil Fischer from 1891 onwards. At the top sits D-(+)-glyceraldehyde, to which all the monosaccharides below are connected by painstaking chemical transformations.

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Prediction preceding experiment in chemistry – how unlucky was John Kirkwood?

Saturday, November 30th, 2019

Some areas of science progressed via very famous predictions that were subsequently verified by experiments. Think of Einstein and gravitational waves or of Dirac and the positron. There are fewer well-known examples in chemistry; perhaps Watson and Crick’s prediction of the structure of DNA, albeit based on the interpretation of an existing experimental result. Here I take a look at a what if, that of John Kirkwood’s prediction of the absolute configuration of a small molecule based entirely on matching up the sign of a measured optical rotation with that predicted by (his) theory.

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The history of Alizarin (and madder).

Thursday, October 18th, 2018

The Royal Society of Chemistry historical group (of which I am a member) organises two or three one day meetings a year. Yesterday the October meeting covered (amongst other themes) the fascinating history of madder and its approximately synthetic equivalent alizarin. Here I add a little to the talk given by Alan Dronsfield on the synthesis of alizarin and the impact this had on the entire industry.

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Octet expansion and hypervalence in dimethylidyne-λ6-sulfane.

Tuesday, November 28th, 2017

I started this story by looking at octet expansion and hypervalence in non-polar hypercoordinate species such as S(-CH3)6, then moved on to S(=CH2)3. Finally now its the turn of S(≡CH)2.

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Twenty one years of chemistry-related Java apps: RIP Java?

Saturday, June 10th, 2017

In an earlier post, I lamented the modern difficulties in running old instances of Jmol, an example of an application program written in the Java programming language. When I wrote that, I had quite forgotten a treasure trove of links to old Java that I had collected in 1996-7 and then abandoned. Here I browse through a few of the things I found.

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The Chemistry Department at Imperial College London. A history, 1845-2000.

Friday, February 10th, 2017

The book of the title has recently appeared giving a rich and detailed view over 417 pages, four appendices and 24 pages of photographs of how a university chemistry department in the UK came into being in 1845 and its subsequent history of discoveries, Nobel prizes and much more. If you have ever wondered what goes on in an academic department, populated by and large by very bright and clever personalities and occasionally some highly eccentric ones, then go dip into this book.

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Revisiting (and maintaining) a twenty year old web page. Mauveine: The First Industrial Organic Fine-Chemical.

Thursday, February 2nd, 2017

Almost exactly 20 years ago, I started what can be regarded as the precursor to this blog. As part of a celebration of this anniversary,[1] I revisited the page to see whether any of it had withstood the test of time. Here I recount what I discovered.

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References

  1. P.W. May, S.A. Cotton, K. Harrison, and H.S. Rzepa, "The ‘Molecule of the Month’ Website—An Extraordinary Chemistry Educational Resource Online for over 20 Years", Molecules, vol. 22, pp. 549, 2017. http://dx.doi.org/10.3390/molecules22040549

The “hydrogen bond”; its early history.

Saturday, December 31st, 2016

My holiday reading has been Derek Lowe’s excellent Chemistry Book setting out 250 milestones in chemistry, organised by year. An entry for 1920 entitled hydrogen bonding seemed worth exploring in more detail here.

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

Tuesday, February 9th, 2016

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