Professor Emeritus Klaus Hafner, Technical University of Darmstadt, Germany, passed away on January 25, 2021. He was well-known for his work on conjugated π-systems such as azulenes, fulvenes, or heptalenes—in particular, for the Ziegler–Hafner synthesis of azulenes [1–3], which he co-developed with Karl Ziegler in 1955.

Klaus Hafner was born on December 10, 1927, in Potsdam, Germany. He studied chemistry at the University of Marburg, Germany, from 1946 to 1951. He received his Ph.D. in organic chemistry in 1951 from the University of Marburg under the supervision of Hans Meerwein. He completed his habilitation in 1955 at the Max Planck Institute for Coal Research, Mülheim an der Ruhr, Germany, working with Karl Ziegler. From 1962 to 1964, Hafner served as Professor at the Ludwig Maximilian University of Munich, Germany. In 1965, he joined the Technical University of Darmstadt, where he remained until his retirement in 1996.

Among other honors, Klaus Hafner received the Adolf-von-Baeyer Memorial Medal from the Gesellschaft Deutscher Chemiker (GDCh, German Chemical Society) and the Carus Prize from the city of Schweinfurt, Germany, both in 1980. He also was an Honorary Professor at East China University, Shanghai, a Member of the German Academy of Sciences Leopoldina, and a Chemistry Europe Fellow. He was a long-time Editor of Justus Liebigs Annalen der Chemie and also served as an Editor for Chemische Berichte and Topics in Current Chemistry. He played an important role in the founding of the journals European Journal of Organic Chemistry and European Journal of Inorganic Chemistry, which were formed as a result of the merger of separate national journals from across Europe such as Chemische Berichte and Liebigs Annalen.

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References

• [1] Eine rationelle Synthese des Azulens (in German),
  K.Ziegler, K. Hafner,
  Angew. Chem. 1955, 67, 301–301.
  https://doi.org/10.1002/ange.19550671103 (in German),
• [2] Zur Kenntnis Der Azulene I. Eine Neue Azulen-Synthese (in German),
  K. Hafner,
  Justus Liebigs Ann. Chem. 1957, 606, 79–89.
  https://doi.org/10.1002/jlac.19576060109,
• [3] Neuere Ergebnisse der Azulen-Chemie (in German),
  K. Hafner,
  Angew. Chem. 1958, 70, 419–430.
  https://doi.org/10.1002/ange.19580701402

Selected Publications

• Untersuchungen Über aromatische Diazoverbindungen, II. Verfahren zur Herstellung Aromatischer Sulfonsäurechloride, Eine Neue Modifikation der Sandmeyerschen Reaktion (in German),
  H. Meerwein, G. Dittmar, R. Göllner, K. Hafner, F. Mensch, O. Steinfort,
  Chem. Ber. 1957, 90, 841–852.
  https://doi.org/10.1002/cber.19570900602
• Fulvene — Isomere benzoider Verbindungen (in German),
  K. Hafner, K. H. Häfner, C. König, M. Kreuder, G. Ploss, Günter Schulz, E. Sturm, K. H. Vöpel,
  Angew. Chem. 1963, 75, 35–46.
  https://doi.org/10.1002/ange.19630750107
• Cyclisch konjugierte 5- und 7-Ringsysteme, I. Synthesen und Reaktionen von Fulvenaldehyden (in German),
  K. Hafner, K. H. Vöpel, G. Ploss, C. König,
  Justus Liebigs Ann. Chem. 1963, 661, 52–75.
  https://doi.org/10.1002/jlac.19636610105
• N-Carbäthoxy-azepin (in German),
  K. Hafner, C. König,
  Angew. Chem. 1963, 75, 89–90.
  https://doi.org/10.1002/ange.19630750117
• Structure and Aromatic Character of Non-benzenoid Cyclically Conjugated Systems,
  K. Hafner,
  Angew. Chem. Int. Ed. Engl. 1964, 3, 165–173.
  https://doi.org/10.1002/anie.196401651
• 1,3,5-Tri-tert-Butylpentalene. A Stabilized Planar 8π-Electron System,
  K. Hafner, H. U. Süss,
  Angew. Chem. Int. Ed. Engl. 1973, 12, 575–577.
  https://doi.org/10.1002/anie.197305751

Also of Interest

• ChemPubSoc Europe Fellows Program,
  Eva E. Wille,
  ChemistryViews.org 2015.
  A Unique Experiment – A Unique Success: European Chemical Societies Instigate Honors Program