Background

Ethnicity: Von Baeyer's father was a Prussian soldier (later a general). His mother was from the Jewish family.

Adolf von Baeyer was born on October 31, 1835 in Berlin, Germany. The son of the noted geodesist and lieutenant-general in the Royal Prussian Army Johann Jacob Baeyer (1794-1885) and his wife Eugenie Baeyer née Hitzig (1807–1843). Baeyer lost his mother at young age while she was giving birth to his sister Adelaide.

His father took part in the government project to measure degrees of latitude and longitude directed by the astronomer W. F. Bessel. He subsequently participated in a general European measurement program and published these results, as well as other investigations on the shape of the earth. Baeyer’s mother was the daughter of Julius Eduard Hitzig, a criminal judge. Her uncle, the art historian Franz Kugler, and her grandfather made Baeyer’s first home on Friedrichstrasse a center for Berlin literary life by attracting E. T. A. Hoffman and others for weekly evenings of conversation. Baeyer’s mother was Jewish but had been converted to the Evangelical faith and had been confirmed by Schleiermacher. Baeyer was of the same faith as his parents.

Education

Baeyer’s early education at the Friedrich-Wilhelms Gymnasium and at the University of Berlin under P. G. Dirichlet and G. Magnus emphasized mathematics and physics. In 1856, after a year’s military service, he decided to study experimental chemistry with R. Bunsen in Heidelberg, where the emphasis was on applied physical chemistry. Dissatisfied with this approach, Baeyer in 1858 entered Kekule’s private laboratory in Heidelberg. Since he was pleased with Kekuld’s tuition in organic chemistry, Baeyer followed him to Ghent and remained there until 1860, taking time out only in 1858 to receive his doctoral degree from Berlin for work on arsenic methyl chloride. Adolf von Baeyer received his PhD in 1858 on his work on cacodyl compounds. Although the work was done in Heidelberg at Kekulé’s laboratory, he received his degree from Berlin University.

Career

In 1856, Adolf Von Baeyer joined Robert Wilhelm Eberhard Bunsen’s laboratory in Heidelberg. There he worked under German organic chemist Friedrich August Kekulé on methyl chloride. The result of this work was published in 1857. Thereafter, he joined Kekulé's private laboratory in Heidelberg and began to work with him on ingenious structure theory.

After receiving his PhD, Baeyer rejoined Kekulé, who was then a professor at the University of Ghent. Here Baeyer worked on uric acid, which led to the discovery of barbituric acid. Barbiturate, a component of sleeping pills, is produced from this acid. The thesis made him eligible for teaching post. Adolf von Baeyer began his academic career as a lecturer (privatdozent) in organic chemistry at the Berlin Gewerbe-Akademie (Trade Academy) in 1860. Although he received a small remuneration he took up the job because the Academy provided him with a spacious laboratory. It is here that Baeyer started his research on indigo.

Until then, the blue pigment could be obtained only from indigo plant grown in India. Consequently the price was too high and the supply was limited. For the chemists, it was a challenge to reproduce the pigment synthetically and make it available at an affordable price.

Although he started his experimentation in 1865, while he was still working at Trade Academy, it took many years to complete. The complex nature of indigo made it a very hard and time consuming task.

Meanwhile in 1866, Baeyer was appointed to the post of the assistant professor in chemistry at the University of Berlin. In the same year, he reduced oxindole to indole using zinc dust. In 1869, he proposed the Baeyer–Emmerling indole synthesis method.

In 1871, Baeyer joined the University of Strasbourg as a full professor and along with working on indigo he kept on experimenting with various products. His theory of carbon-dioxide assimilation in formaldehyde was formed during his tenure here. He also discovered the synthesis of phenolphthalein and obtained synthetic fluorescein during this period.

Four years later in 1875, he shifted to the Ludwig Maximilian University of Munich as professor of chemistry and remained there until his death in 1917. Here he had the opportunity to build up an excellent chemical laboratory and continue with his work on indigo at full force.

In 1882, Bayer published the ‘Baeyer–Drewson indigo syntheses’. It turned out to be an easy route for producing indigo at laboratory scale. However, it was not until the following year that Baeyer could fully determine the structure of indigo.

Apart from working on indigo, Baeyer worked on many other products such as acetylene and polyacetylene. The famous ‘Baeyer strain theory’ of the carbon rings was derived from these experiments. Later, he received the coveted Nobel Prize in chemistry for developing this theory.

In addition, he and his team studied constitution of benzene and also investigated into cyclic terpene. He also worked on cyclic ketone and published the Baeyer-Villiger oxidation theory in 1899. His work on organic peroxides and oxonium compounds also aroused interest among the chemists.

From 1900, von Baeyer started working on triphenylmethane. From this work, a new notion about the chemical composition of pigments began to be developed. Moreover, his works helped to understand the relationship between the optical properties of organic substances and their interior atomic structure to a large extent.

He continued working at the University of Munich almost till his end. During that period, he was considered to be one of the best known teachers in the field of organic chemistry. All through his career, he had nurtured at least fifty talented students, who later became well-known academicians.

Synthesizing of indigo, which took almost eighteen years to complete, was one of Baeyer’s most important works. Although his formula was meant only for laboratory production of the pigment his work paved the way for further experimentation and by 1897, indigo began to be produced commercially.

Synthesis of phenolphthalein, a chemical compound used mainly as an indicator in acid based tritrations, is another of his major works done in 1871. To get the product, he condensed phthalic anhydride with two equivalents of phenol under acidic conditions.

Synthesized fluorescein, which is mainly used as a fluorescent tracer for many applications, is another of his important work. In 1871, he prepared it from phthalic anhydride and resorcinol in the presence of zinc chloride via the Friedel-Crafts reaction.

Achievements

• Baeyer's chief achievements include the synthesis and description of the plant dye indigo, the discovery of the phthalein dyes, and the investigation of polyacetylenes, oxonium salts, nitroso compounds (1869) and uric acid derivatives (1860 and onwards) (including the discovery of barbituric acid (1864), the parent compound of the barbiturates). He was the first to propose the correct formula for indole in 1869, after publishing the first synthesis three years earlier. His contributions to theoretical chemistry include the 'strain' (Spannung) theory of triple bonds and strain theory in small carbon rings. Baeyer's 300 important papers are one of the great monuments of German intellectual life.
  
  In 1881 the Royal Society of London awarded Baeyer the Davy Medal for his work with indigo. In 1884, he was elected the Foreign Honorary Member of the American Academy of Arts and Sciences. His most prominent award came in 1905 when Bayer received the Nobel Prize in Chemistry for his achievements on the advancement of organic chemistry through his work on dyes and hydroaromatic compounds. On his 50th birthday he was raised to the hereditary nobility by King Ludwig II of Bavaria, conferring on him the “von” distinction.
  
  His name is reflected in various "name reactions" as the Baeyer-Villiger Oxidation and Baeyer's reagent. There is also the Von Baeyer nomenclature in structural chemistry and Baeyer strain theory (which granted him the Nobel prize) of alicyclic compounds. In 2009 von Baeyer lunar crater was named after him.

Works

More photos

• book

  • Gesammelte Werke
  • Untersuchungen Uber Die Kakodylreihe
  • Sur un nouveau dérivé de l’acide picrique 1858

Religion

Adolf von Baeyer was raised in the Lutheran religion.

Views

Baeyer’s chemical research was in many ways an extension of Kekule’s work on the tetravalency of carbon. He used this framework to elucidate the structure of compound after compound. His work on indigo indicated that he was not interested merely in synthesis, but also believed that understanding a compound required knowing its exact structure. Baeyer’s work on the stability of ring structures showed his concern with the direction of valence bonds and the extent to which the direction can be changed. With the idea that valence bonds can be strained and with his criticism of existing benzene formulas, Baeyer went beyond Kekule’s earlier picture. His final unwillingness to assign a definite structure to benzene, his work on stable and unstable isomers of isatin and indoxyl, which he called lactim and lactam forms, as well as that on phloroglucinol, pointed up difficulties in determining exact structure, which were later resolved with the concept of tautomerism.

Baeyer’s approach to chemistry, however, was different from that of Kekule. Baeyer had little interest in theoretical statements and attacked most problems empirically. His work on benzene, he explained, was only an experimental investigation and not an attempt to prove a particular hypothesis. He was a master at test-tube analysis, and eschewed complicated apparatus.

Quotations: "I have never planned my experiments to find out if I was right, but to see how the compounds behave."

"This [discovery of a cell-free yeast extract] will make him famous, even though he has no talent for chemistry."

Membership

He was active in the German Chemical Society.

Personality

Even as a child Adolf was highly inquisitive. At the age of eight, he planted date seeds in a series of pots and fed them successively with milk, wine and ink. However, his experiments at the age of twelve were more successful; he found a new double salt of copper.

Physical Characteristics: Baeyer maintained good health and was active till his end.

Connections

In 1868, Baeyer married Adelheid (Lida) Bendemann (1847-1910), the daughter of a family friend, and together the couple had three children: Eugenie, Hans (1875-1941), and Otto.

Father:

Johann Jacob Baeyer

Mother:

Eugenie Baeyer née Hitzig

His mother came from the Jewish Itzig family and converted to Christianity to marry his father.

Spouse:

Adelheid (Lida) Bendemann

child:

Eugenie Baeyer

child:

Hans Baeyer

child:

Otto Baeyer

Sister:

Adelaide Baeyer

collaborator:

Friedrich Kekulé

References

• Encyclopedia of World Scientists Encyclopedia of World Scientists, Revised Edition is a diverse and comprehensive two-volume collection of biographies of scientists. This essential work contains fascinating stories of nearly 1,000 scientists - almost half of whom are female - who have contributed significantly to their fields. All scientific disciplines are represented, as well as all periods of history as far back as 400 BCE. With more than 100 new entries and more than 200 pho
  2007
• Encyclopaedia Britannica
  1990
• Dictionary of Scientific Biography
  1970