Staudinger, Herman

Staudinger was born in Worms on the Rhine on March 23, 1881. Because of his love of plants and flowers, he began to study botany under the direction of George Klebs at Halle University. After graduating from high school in 1899, his father invited him to take chemistry courses to get a better idea of ​​botany. Following his father’s advice, Herman studied chemistry at the universities of Halle, Darmstadt and Munich. Gradually, chemistry became his main interest, and already in 1903, at the age of 22, he received a Ph.D. under the leadership of Daniel Forlander in Galle.

Staudinger continued his research in the field of organic chemistry in the laboratory of D. Thiele at the University of Strasbourg. There, in the course of research on carboxylic acid compounds, he discovered ketenes . In 1907, immediately after completing his scientific work on the chemistry of ketenes, Staudinger, at the age of 26, was appointed an ordinary professor at the Technical University of Karlsruhe, replacing Roland Scholl. In Karlsruhe, he met prominent chemists of the time, such as Karl Engler and Gaber (the founder of high pressure chemistry). At the same time, Staudinger's studies focused on the chemistry of ketenes, reactions involving oxalyl chloride, aliphatic diazocompounds, and the production of butadiene and isoprene ^[1] .

In 1912, H / Willstatter, a world leader in organic chemistry, was appointed director of the newly established Kaiser Wilhelm Institute of Chemistry in Berlin-Dahlem. The Swiss Higher Technical School of Zurich (Eigenössische Technische Hochschule) proposed the vacant Department of Chemistry to Staudinger, who had just published his first book, On Ketens ^[2] . In Zurich, Staudinger continued his research in the field of organic synthesis. In addition, he began to study physiologically active natural compounds. Together with Leopold Ruzicka (who received the Nobel Prize in Chemistry in 1939), Staudinger determined the structure of natural pyrethrins and developed ways to synthesize these important natural insecticides.

During the First World War, Staudinger also conducted research on flavorings, substitutes for natural products that were in short supply during the war. In addition to successfully obtaining a synthetic pepper substitute, Staudinger and Reichstein conducted an analysis of natural coffee flavors. At the end of the study, they proposed a synthetic substitute - furfuryl mercaptan mixed with methyl mercaptan, which they began to produce commercially.

During this period, Staudinger was a typical practical chemist within the framework of organic chemistry, which was already a very old and respected science, led by Adolf von Bayer, Emil Fischer and Richard Willstatter. By 1914, organic chemists synthesized more than 100,000 chemical compounds used in various industries, including dyes and pharmaceuticals. Not yet at the age of 40, Staudinger was considered a leading organic chemist. During the 1920s, Staudinger decided to leave the safe and prestigious refuge of classical organic chemistry in order to meet the stormy blue water of polymer chemistry. Staudinger's pioneering spirit allowed him to break away from the typical thinking of conservative chemists and develop new revolutionary concepts ^[3] .

In 1926, he was appointed to the department at the University of Albert Ludwig in Freiburg, where he devoted all his efforts to creating and expanding the boundaries of polymer science. His research interests included natural rubber, cellulose, and synthetic polymers such as polyoxymethylene, polystyrene, and polyethylene oxide, which Staudinger considered model systems for much more complex biopolymers. In addition to creating new synthetic polymers, Staudinger tried to determine the molecular weights of the polymers by analyzing the end groups, performing viscometry of the polymer solutions and using electron microscopy.

Staudinger has always maintained close relations with industry in order to obtain funds for his research, and willingly acted as a technical consultant for companies interested in plastics and rubber. For many years, the Förderverein Institute for the Chemistry of High-Molecular Compounds was formed by the supervisors of various companies that sponsored polymer research in Freiburg. Staudinger's scientific seminars, which began in 1950, were gathered by both academic and industrial chemists, and soon became the largest annual conference on polymer chemistry (with more than 700 permanent participants by the 1990s).

Staudinger's studies have been published in over 800 publications with a total of 10,000 printed pages. In addition, he summarized research materials in his autobiography, Arbeitserinnerungen (from Organic Chemistry to Macromolecules), published in 1970 ^[4] . His collected works, entitled Das Wissenschaftliche Werk von Hermann Staudinger (Scholarly Works by Hermann Staudinger), were edited by Magda Staudinger and published between 1969 and 1976. ^[5] .

For many years, the Staudinger textbook, entitled Die hochmolekularen organischen Verbindungen Kautschuk und Cellulose (High Molecular Organic Compounds, Rubber and Cellulose) ^[6] , published in Berlin in 1932, was the chemical "Bible" for many scholars. In 1947, Staudinger created the new scientific journal Makromolekulare Chemie with Wepf & Company, published in Basel. For more than 50 years, this journal has remained a leader in the field of polymer chemistry.

In addition, Staudinger could not stay away from moral and political issues that went beyond academic chemistry. During the First World War, he publicly criticized the use of chemical weapons and spoke in this matter as an opponent to his friend F. Gaber, who developed poison gas for the German army. In 1917, Staudinger published a document based on a calculation of the industrial potentials of the warring parties. Based on the results of calculations, he came to the conclusion that the war was already virtually lost by Germany and should be immediately ended, since any further bloodshed is pointless. His bold statements contradicted the nationalist spirit of Germany of that period.

The pacifist remarks by Staudinger led to the fact that his patriotism was questioned many times. In the end, this led to the fact that in 1934, during the Nazi period, the dean of the University of Freiburg, the famous German philosopher Martin Heidegger, initiated the procedure for his dismissal. Although Staudinger was questioned by the Gestapo and was forced to accept the resignation, his removal was postponed and then canceled, provided that he would no longer publicly condemn the new government. However, all of his requests for permission to leave the country to attend conferences after 1937 were rejected.

Posts

Professor at universities ^[7] :

• 1908-1912: Higher Technical School in Karlsruhe
• 1912-1926: Federal High School in Zurich
• 1926-1951: University of Freiburg
• 1940-1956: Director of the State Institute of Macromolecular Compounds.

Early work

After receiving a Ph.D. degree (Ph.D.) at the University of Halle in 1903, Staudinger began working at the University of Strasbourg (France).

Here he discovered ketenes - a family of molecules described by the general formula depicted in Fig. 1 . Ketenes will subsequently prove to be important intermediates in the synthesis of penicillin and amoxicillin antibiotics.

In 1907, Staudinger became an assistant professor at the Technical University of Karlsruhe (Germany). There he successfully identified many useful organic compounds (including synthetic coffee flavors), more fully studied by Rolf Mulhaupt.

Major works

The main works are devoted to the chemistry of macromolecular compounds .

• 1919 : He proposed a method for replacing the oxygen atom of a carbonyl group with an imine group using triphenylphosphinimines ( Staudinger reaction Fig. 2 ).
• 1922 : He proved that polymers are compounds consisting of large molecules whose atoms are linked together by covalent bonds . To describe such molecules, he introduced the concept of a macromolecule into science. He advanced the theory of the chain structure of macromolecules, which he subsequently supplemented with the concepts of a branched macromolecule and a three-dimensional polymer network. He showed the relationship between the molecular weight of the polymer and the viscosity of its solution, which allowed us to create a viscometric method for determining the molecular weight. He proposed reactions of polymer-analogous transformations .
• 1947 : Founded the magazine Die makromolekulare Chemie .

Macromolecule Research

In 1920, German Staudinger, professor of organic chemistry at the Technical University of Zurich, excited the scientific community by announcing that materials, such as natural rubber, have molecules with a very high molecular weight ( Fig. 3 ). In an article entitled Über Polymerisation ^[8], Staudinger presented several reactions that allow the synthesis of heavy molecules by combining a large number of short molecules of the same type. During these reactions, called "polymerization", the free monomers covalently joined together in a chain.

This new theory, described by Staudinger as macromolecular in 1922, encompassed both natural and synthetic polymers and paved the way for the synthesis of new polymeric materials for various purposes. Now many modern technologies are based on polymer materials and biopolymers designed at the molecular level. Achievements of polymer chemistry are used in a variety of fields: from packaging food, textile fibers, auto parts and toys to water treatment membranes and carriers that regulate the release of drugs into the blood and biopolymers for tissue engineering.

Staudinger's theory, however, turned out to be complicated for many of his contemporaries. The scientific community was very reluctant to acknowledge the existence of extremely large molecules with molecular weights of more than 5000. Opponents of Staudinger’s ideas explained the specific properties of polymer materials by the presence of micelle-like aggregates found experimentally for soap molecules in their structure. Moreover, some scientists were convinced that the size of the molecule cannot exceed the size of the unit cell determined by X-ray diffraction analysis.

Staudinger, adhering to the empirical approaches of classical organic chemistry, conducted a series of experiments confirming the existence of macromolecular compounds. Natural rubber was chosen as the model system because Karl Harries and Rudolf Pummerer independently suggested that natural rubber is a collection of small cyclic blocks of polyisoprene non-covalently linked by “partial valencies” of double bonds. Such aggregates, in his opinion, should have been destroyed upon the disappearance of double bonds in the process of hydrogenation. A practical experiment on the hydrogenation of rubber showed that the hydrogenated sample is very similar in properties to natural, which confirmed the Staudinger hypothesis.

In the late 1920s, Staudinger provided another proof of his theory based on a viscometric study of polymer solutions. Studies have confirmed that the molecular weight of polymers remains almost unchanged during chemical modification.

However, even despite impressive experimental data, Staudinger continued to meet resistance from leading organic chemists for almost two decades. For example, Heinrich Wieland, the 1927 Nobel Prize in Chemistry, wrote to Staudinger: “Dear colleague, give up the idea of ​​large molecules, organic molecules with a molecular mass of more than 5000 do not exist. Clean your products and rubbers, and they will begin to crystallize, thereby showing their low molecular weight. "

In his autobiography, Staudinger writes: “My colleagues were very skeptical of my theory, and everyone who met my publications in the field of low molecular chemistry asked me why I neglect this interesting area and continue to work with poorly studied and uninteresting compounds like rubber and synthetic polymers. At that time, the chemistry of these compounds, due to their properties, was often called the chemistry of lubricants ” ^[9] .

Staudinger never stopped promoting his concept of polymer structure, despite the distrust of his colleagues in many of his methods and results. In a lively debate, he eloquently defended his ideas from all attacks, using his ingenuity, perseverance and inexhaustible enthusiasm. From the late 1920s to the mid-1930s, Staudinger's macromolecular theory began to be accepted by the scientific community. Although some of his opponents continued to persist in their objections, the Staudinger concept found application in industrial processes.

And finally, on December 10, 1953, Staudinger received his award for developing the theory of macromolecules and his contribution to the development of polymer chemistry - the Nobel Prize in chemistry.

Nobel Prize

Nobel Prize in Chemistry ( 1953 ):

The scientist ended the Nobel speech with a description of his vision of the future of science: “In the light of new discoveries in the chemistry of high molecular compounds, the miracle of life shows the exceptional multitude and perfection of structures characteristic of living matter” ^[10] .

Nature uses a very small amount of monomers, such as amino acids and monosaccharides, to produce a huge variety of biopolymers with specific functions in cell structures, transport, catalysis and replication. Today, innovations in the field of living sciences, especially biotechnology, will continue to stimulate the creation of new synthetic biopolymers, with unprecedented control of molecular architecture and biological activity ^[11] .

Thus, the macromolecular theory combined the chemistry of living and polymer science.

Other awards, honors, memorials

• 1929 - Extraordinary Member of the Heidelberg Academy of Sciences
• 1930 -
• 1932 - Member of the German Academy of Naturalists Leopoldina
• 1952 - The Great Federal Cross "For Merit"

In 1999, a memorial plaque was erected on the university building in Freiburg by the German Chemical Society. Schools in Worms and Freiburg, a gymnasium in Erlenbach are named after G. Staudinger. The Swiss Higher Technical School of Zurich established the G. Staudinger Prize in macromolecular chemistry.

In 1927, Staudinger married Magda Voight ^[12] , who was a specialist in plant physiology. She became for her husband a faithful companion in work. There were no children in the family.

• Hermann Staudinger (1905). "Ketene, eine neue Körperklasse." Berichte der deutschen chemischen Gesellschaft. 38 (2): 1735-1739. doi: 10.1002 / cber.19050380283.
• Staudinger, H. (1920). Über Polymerisation. Ber. Deut. Chem. Ges. 53 (6): 1073. doi: 10.1002 / cber.19200530627.
• Staudinger, H. (1933). "Viscosity investigations for the examination of the constitution of natural products of high molecular weight and of rubber and cellulose." Trans. Faraday Soc. 29 (140): 18-32. doi: 10.1039 / tf9332900018.
• Staudinger, H .; Heuer, W .; Husemann, E .; Rabinovitch, IJ (1936). "The insoluble polystyrene." Trans. Faraday Soc. 32: 323–335. doi: 10.1039 / tf9363200323.
• Arbeitserinnerungen, Hdlb., 1961
• Macromolecular chemistry, 1953 nobel lecture

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