Posts Tagged ‘detective’

Conference report: an example of collaborative open science (reaction IRCs).

Thursday, May 25th, 2017
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It is a sign of the times that one travels to a conference well-connected. By which I mean email is on a constant drip-feed, with venue organisers ensuring each delegate receives their WiFi password even before their room key. So whilst I was at a conference espousing the benefits of open science, a nice example of open collaboration was initiated as a result of a received email.

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William Henry Perkin: The site of the factory and the grave.

Monday, March 11th, 2013
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William Henry Perkin is a local chemical hero of mine. The factory where he founded the British (nay, the World) fine organic chemicals industry is in Greenford, just up the road from where we live. The factory used to be close to the Black Horse pub (see below) on the banks of the grand union canal. It is now commemorated merely by a blue plaque placed on the wall of the modern joinery building occupying the location (circled in red on the photo).

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Historical detective stories: colourful crystals.

Friday, October 21st, 2011
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Organic chemists have been making (more or less pure) molecules for the best part of 180 years. Occasionally, these ancient samples are unearthed in cupboards, and then the hunt for their origin starts. I have previously described tracking down the structure of a 120 year-old sample of a naphthalene derivative. But I visited a colleague's office today, and recollected having seen a well-made wooden display cabinet there on a previous visit. Today I took a photo of one of the samples:

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A historical detective story: 120 year old crystals

Wednesday, November 17th, 2010
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In 1890, chemists had to work hard to find out what the structures of their molecules were, given they had no access to the plethora of modern techniques we are used to in 2010. For example, how could they be sure what the structure of naphthalene was? Well, two such chemists, William Henry Armstrong (1847-1937) and his student William Palmer Wynne (1861-1950; I might note that despite working with toxic chemicals for years, both made it to the ripe old age of ~90!) set out on an epic 11-year journey to synthesize all possible mono, di, tri and tetra-substituted naphthalenes. Tabulating how many isomers they could make (we will call them AW here) would establish beyond doubt the basic connectivity of the naphthalene ring system. This was in fact very important, since many industrial dyes were based on this ring system, and patents depended on getting it correct! Amazingly, their collection of naphthalenes survives to this day. With the passage of 120 years, we can go back and check their assignments. The catalogued collection (located at Imperial College) comprises 263 specimens. Here the focus is on just one, specimen number number 22, which bears an original label of trichloronaphthalene [2:3:1] and for which was claimed a melting point of 109.5°C. What caught our attention is that a search for this compound in modern databases (Reaxys if you are interested, what used to be called Beilstein) reveals the compound to have a melting point of ~84°C. So, are alarm bells ringing? Did AW make a big error? Were many of the patented dyes not what they seemed?

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