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Von Pechmann was born in Nürnberg, the only son of a doctor, who was also named Hans.The von Pechmanns had distinguished themselves as soldiers; in 1702, von Pechmann's ancestor Martin Günther von Pechmann, a general of artillery in the Bavarian army, had been raised to the rank of a baron of the Holy Roman Empire by Leopold I. [6]
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1898: Synthesis of polyethylene, the most common plastic, by Hans von Pechmann [159] 1898: First synthesis of purine by Emil Fischer. He had also coined the word in 1884. [160] Early 20th century: Schlenk flask by Wilhelm Schlenk [161] 1900s: Haber process by Carl Bosch and Fritz Haber [133] 1902: Ostwald process by Wilhelm Ostwald [162]
Hans von Pechmann: Chemist, renowned for his discovery of diazomethane in 1894. Pechmann condensation and Pechmann pyrazole synthesis. Julius Richard Petri: Bacteriologist who is generally credited with inventing the Petri dish while working as assistant to Robert Koch. Emil Pfeiffer: Discovery of Infectious mononucleosis
in 1899 Hans von Pechmann added diazomethane to ether, and noted the formation of polymethylene, a type of polyethylene, identified in 1900 by Eugen Bamberger and Friedrich Tschirner, but had not realised that it has any commercial significance; ICI in Cheshire in England will, in 1933
Polyethylene was first synthesized by the German chemist Hans von Pechmann, who prepared it by accident in 1898 while investigating diazomethane. [12] [a] [13] [b] When his colleagues Eugen Bamberger and Friedrich Tschirner characterized the white, waxy substance that he had created, they recognized that it contained long −CH 2 − chains and termed it polymethylene.
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Two German chemists also preceded Schlotterbeck in discovery of the reaction, Hans von Pechmann in 1895 and Viktor Meyer in 1905. [4] [5] The reaction has since been extended to the synthesis of β-keto esters from the condensation between aldehydes and diazo esters. [6] The general reaction scheme is as follows: General Scheme for Buchner Reaction