I promise you that I will have a little romance later. But to really understand the romance, you need to first understand the science – a little organic chem. Let’s start with the name—octo means that there are eight carbons (one at each vertex) and cyclic means that they are arranged in a circle (or rather a stop sign). 2-4-6-8 Cyclic Octo-tetraene:
Carbon can form a single, double or triple bond with another carbon: C-C or C=C or C≡C. What “ene” means is that there is a Carbon=Carbon double bond. Tetraene means that there are four such double bonds and the 2-4-6-8 means that they alternate around the stop sign. As each Carbon has four bonds, each Carbon also has one Hydrogen (H).
There are ways to recognize the presence of a carbon=carbon double bond, most notably – if you add bromine, the solution will turn purple.
Math-phobic bloggieites may skip this paragraph with no harm: Carbon likes for its bonds to be at a 114 degree angle. The angularity of an equilateral structure of n vertices is determined by the following formula: (n-2)*180/n. As you can see readily a five carbon circle gives you a 108 degree structure and a six carbon structure gives you a 120 degree structure. An eight carbon structure would of course give you a 135 degree structure which is only mildly tortured and should in theory be attainable. Three and four carbon cyclic structures are quite unstable as are all those with really large numbers of carbons in the ring.
There are extreme difficulties in creating such a chemical as 2-4-6-8 cyclic octo-tetraene. The biggest one is that it will collapse from its intrinsically unstable state to the extremely stable benzene. There is no such thing as 2-4-6 cyclic hexa-triene.
Instead there is benzene. There are no carbon-carbon double bonds, but rather a single benzene bond tying all of the electrons and nuclei together in a stable structure — the description I recall is a cloud of electrons. Here is the standard diagram of benzene:
Benzene is so important that all of organic chemistry is divided into two parts – the chemicals which contain benzene (the aromatics) and the chemicals which do not (the alkyds). As Benzene has no carbon=carbon double bonds, it does not turn purple when you add bromine.
ENOUGH SCIENCE – ON TO THE ROMANCE.
THE QUAGGA.The Quagga
, a close relative of the zebra, died extinct. My Organic prof said that the last one died in the St.Louis zoo in the mid-1870’s – wiki says the Amsterdam zoo.
In those days, the Germans were the best chemists. And being German, there was a hierarchy between and within universities, such that everybody understood that the best chemist in the world was Dr. Emil Fischer of the University of Wurzberg. The zoo with the last quagga sent Dr. Fischer the gall bladder of the last quagga for his further research.
Dr. Fischer didn’t really know what to do with such a gift. So he put it up on a shelf and thought about it for nine months or so. (What would you do if somebody sent you an organ of the last living member of an extinct species?)
Eventually, Dr. Fischer decided he would use the gall bladder to create 2-4-6-8 cyclic octo-tetraene. He fiddled about for a while, and eventually decided he had succeeded. He dropped in bromine, and the solution turned purple. The other tests for carbon=carbon double bonds were also positive.
THE NEXT FORTY YEARS:
Over the next forty years, organic chemists endeavored to recreate 2-4-6-8 cyclic octo-tetraene. They all failed. Stuff would resolve into benzene or just go weird. Somewhere around WWI, the organic chem world concluded that, while Dr. Fischer was undeniably a brilliant chemist – he must have been mistaken about 2-4-6-8 cyclic octo-tetraene. There was no such thing.
THE NEXT QUARTER CENTURY:
Nobody gave any thought whatsoever to 2-4-6-8 cyclic octo-tetraene.
The Allied tanks rolled into Berlin in 1945. On the outskirts of Berlin were tank car after tank car after tank car – each filled to the top with 2-4-6-8 cyclic octo-tetraene.
Germany in WWII was under enormous stress to create items which naturally came from outside of Central Europe. A chemist named Reppe did wonderful stuff with acetylene, C=C, to create all sorts of other chemicals. He did Nobel quality work. He is one of the rare scientists to be denied a Nobel for political reasons – he also experimented on Jews. My prof said he died in prison in the early 50’s. But here is wiki
– no Nobel but no disgrace. (in the defense of my prof, you should understand that I am trying here to retell a story which I heard once over a third of a century ago – and the inaccuracies of my memory are likely greater than the inaccuracies of his story.)
The 2-4-6-8 cyclic octo-tetraene was a byproduct of Reppe’s work with acetylene.
THE NEXT THIRD OF A CENTURY:
I was taught that chemists all over the world were trying to come up with some conceivable use for the damned stuff.
Another third of a century has now passed, and I have no idea if anybody has figured out what to do with it.
It is, however, my hope that this post will finally cause Bloggieites to cease their annoying pestering of e&z for an organic chemistry post.