March 20, 2007 Leave a comment
Hermann Staudinger (1881 – 1965) is the father of modern polymer chemistry and the man who gave us the concept of the macromolecule. Therefore I think it is only appropriate that he should lend his name to this blog and that I should quickly discuss who he was, before this blog starts in earnest.
Staudinger was born in Worms, an old Roman foundation and studied chemistry at the universities of Halle, Darmstadt and Munich. After receiving his doctorate from Halle (only four years after he matriculated at the university), he habilitated at the University of Strassbourg and at the age of 26 was appointed to a professorship in organic chemistry at the Technische Hochschule Karlsruhe and later on at the ETH Zurich as a successor to the famous Richard Willstaetter (who had received the Nobel Prize in Chemistry in 1915). At the time, Staudinger was only 31 years old. It was at Zurich, where his work on azide chemistry and the synthesis of synthetic diamonds first created a “bang” in the scientific world in more than one way. First there was the reaction named after him, the Staudinger reaction. This allowed the gentle reduction of an azide to an amine:
Mechanistically, the triphenyl phosphine reacts with the azide to form a phosphazide, which subsequently looses nitrogen to give an iminophosphorane. Aqueous workup then leads to the amine.
The other “bang” resulted from Staudinger’s attempts to create synthetic diamonds: in a quarry close to Zurich he conducted experiments, in which he reacted carbon tetrachloride (InChI=1/CCl4/c2-1-1) with sodium metal (InChI=1/Na) in a closed container. The idea, of course, was that the reaction would form sodium chloride (InChI=1/ClH.Na/h1H;/q;+1/p-1) and elemental carbon (InChI=1/C), which would arrange into a diamond lattice given the high pressures generated by the explosion.
During his time in Karlsruhe, Staudinger started to pursure research into rubber chemistry and in a paper in 1920 floated the idea that rubbers and and polymers in general were composed of small repeating molecular units, which were all covalently linked.1 The idea put him at odds with a number of leading chemists of his time, most notably Emil Fischer, who, like many others at the time believed Grahams’s colloid theory, which stated that micellar self-assembly of small molecules, which were non-covalently linked, was essentially responsible for polymer properties. Another doubtor was Wieland, who wrote in a letter to Staudinger2:
“Dear Colleague, abandon your idea of large molecules, organic molecules with molecular weights exceeding 5000 do not exist. Purify your products such as rubber, they will crystallize and turn out to be low molecular weight compounds”
In his memoirs, Staudinger later added:2
“Those colleagues who were aware of my early publications in the field of low molecular weight chemistry asked me why I had decided to quit these beautiful fields of research and why I devoted myself to such disgisting and ill-defined compounds such as rubber and synthetic polymers which at that time in view of their properties were referred to as grease chemistry (“Schmierenchemie”).”
In 1922, he published a paper concerning the hydrogenation of natural rubber3 and it was in this paper that he first coined the term “macromolecule.” Upon moving to the University of Freiburg in 1926, Staudinger started to pursue grease chemistry full time, continuing to amass experimental evidence indicating the existence of macromolecules. His studies on crystalline poly(oxy methylene) (POM) using X-ray crystallography clearly proved the existence of macromolecules.4 Overall, his research in macromolecular chemistry resulted in the publication of 644 papers and the award of the Nobel Prize for Chemistry in 1953.
Rolf Muelhaupt, Staudinger’s successor in the chair for Macromolecular Chemistry at Freiburg, has recently published an eminently readable biography2 about the man and his chemistry, which I would urge you all to read.
 Staudinger, H. Ber. Deut. Chem. Ges., 53, 1073 (1920)
 Muelhaupt, R., Angew. Chem. Int. Edn., 43(9), 1054 (2004) DOI: 10.1002/anie.200330070).
 Staudinger, H., Fritschi, J., Helv. Chim. Acta, 5, 785 (1922)
 Staudinger, H., Johner, H., Signer, H., Mie, G., Hengstenberg, J., Z. Phys. Chem., 126, 425 (1927)