Friedrich Reinitzer

Frederick Richard Cornelius Reinitzer ( born February 25, 1857 in Prague, † February 16, 1927 in Graz) was an Austrian botanist, chemist and discoverer of the liquid crystals.

Life

Reinitzer was born in 1857 the son of a railway official in Prague. From 1867 to 1873 he attended secondary school in Prague. At the chemical- technical school of the Technical University of Prague and at the German University of Prague in 1873 he began his studies. In 1877 he completed his studies and then became an assistant for general and analytical chemistry. In the years 1882-1888 he was an assistant in botany at the Botanical Institute of Physiology of Prague German University. In 1883 he was awarded the doctorate at the German Technical University in Prague for Silo and technical microscopy. Reinitzer 1888 where he was appointed associate professor of Botany, Silo and technical microscopy. In 1891 he was an associate professor of agricultural chemistry at the German Technical University in Prague.

In 1895 he moved to Graz, where he was appointed at the local Technical College, first as an associate professor and in 1902 full professor of botany, organic raw teaching and technical microscopy.

The chemist Benjamin Reinitzer (1855-1928) was the brother of Friedrich Reinitzer.

Work

The most significant achievement Reinitzer was the discovery of liquid crystalline phase. 1888 Reinitzer experimented with ester derivatives of cholesterol. The cholesterol he won by extraction from carrots. With the derivatives he hoped to obtain information about the structure of cholesterol. Previously could already observe a distinct color change upon melting of various cholesterol derivatives some scientists. One of the synthesized compounds was Reinitzer of the cholesteryl benzoate, benzoic acid esters of cholesterol, its molar mass he wanted to determine. Also on cholesteryl Reinitzer could find a color appearance in the region of the melting point. New, however, was that this substance while at 145 ° C has its melting point, but the melt represented a relatively viscous and especially cloudy liquid. By further heating at 178.5 ° C, a clear from the turbid liquid. The process was reversible and reproducible during cooling. Even further purification processes did not alter the behavior of the substance. Such alleged melting intervals are usually observed in contaminated compounds; Pure substances, however, have a " sharp " melting point. Reinitzer knew this phenomenon can not be interpreted further and pulled the Prague crystallographer Viktor Leopold Zepharovic (1830-1890) for help. Also did not find any explanation for this phenomenon and recommended Reinitzer that this should apply to Otto Lehmann in Aachen. On March 14, 1888 Reinitzer wrote to Lehmann, who was then a lecturer at the Royal. Technical University of Aachen was. There ensued a correspondence and the exchange of samples - cholesteryl benzoate and cholesteryl acetate. Lehmann noted in the study of so-called Reinitzerschen preparations that they as well as he examined the silver between the liquid and solid phases have a third phase. This phase shows an example of an otherwise observed only in solids birefringence.

The correspondence between Lehmann and Reinitzer ended on April 24, 1888, and many questions remained unanswered. Reinitzer presented on May 3, 1888 at a meeting of the Vienna Chemical Society on the results, making note of the contributions of Lehmann and Zepharovic.

Reinitzer discovered the cholesterol esters three important characteristics of cholesteric liquid crystals:

  • The presence of two " Melting points " (melting point and clear point )
  • The reflection of circularly polarized light
  • The ability to rotate the direction of polarized light

Even if the 1888 is considered the birth of the liquid crystal research, remained the " flowing crystals " - the term was later coined by Otto Lehmann - almost 80 years, a phenomenon without much practical application. Only at the beginning of the 1970s could be found with the electro-optical displays based on liquid crystals (LCDs) a first application in watches, calculators and the like. Until the wide application in flat-panel televisions another 35 years would pass.

Writings

  • About the physiological significance of the transpiration of plants. In Proceedings of the Academy of Sciences, Vienna, 1881
  • Analysis of a vegetable fat. In Proceedings of the Academy of Sciences, Vienna, 1882
  • About the constituents of the leaves of Fraxinus excelsior. In Monatshefte fur Chemie, 3/1882
  • About Hydro carotene and carotene. In Proceedings of the Academy of Sciences, Vienna, 1886
  • Contributions to the Knowledge of cholesterol. In Monatshefte fur Chemie, 9/1888
  • About the true nature of Gummifermentes. In Journal of Physiological Chemistry, 14 ( 5) / 1890, pp. 453-470, Strasbourg, 1890
  • The Gerbstoffbegriff and its relationship with the plants chemistry. In lotus., Volume 11, 1891
  • About the cell wall -dissolving enzyme of barley. In Hoppe- Seyler 's Journal of Physiological Chemistry, 23 (2 ), pp. 175-208, Strasbourg, 1897,
  • About Mushrooms as nurses and breadwinner for higher plants. In releases of science Association for Styria, Graz, 1907
  • On the history of liquid crystals. In Annals of Physics, Volume 27, Episode 4, Leipzig, 1908
  • About the enzymes of acacia gum and some other types of rubber. In Hoppe- Seyler 's Journal of Physiological Chemistry, Volume 61 (4/5 ), pp. 352-394, Strasbourg, 1909
  • About the respiration of plants. , Inaugural Address, Graz, 1909
  • Response concerning the enzymes of acacia gum. In Hoppe- Seyler 's Journal of Physiological Chemistry, Volume 64 (2 ), pp. 164-168, Strasbourg, 1910
  • Contribution to the knowledge of the structure of the flax and hemp fiber. In Archives of Chemistry and Microscopy, Vienna, 1911
  • About the Lupulinbestimmung in hops. In reports. the Austrian. Society for Förderg. of chem. Ind., 1889.
  • Occurrence and extraction of rubber latex. In releases of science Association for Styria, Graz, 1912
  • The resins and vegetable waste. In releases of science Association for Styria, Graz, 1914
  • Studies on Siambenzoe. In Archiv der Pharmazie, Volume 252, Berlin, 1914
  • Dextrinfabrikation. In dictionary of technology and its auxiliary sciences, Stuttgart, 1919
  • Studies on the olive resin. In Proceedings of the Academy of Sciences, Volume 133, Vienna, 1926
  • The recovery of benzoic and Benzoevorharzes. In Archiv der Pharmazie, Volume 264, Leipzig, 1926
Otto Lehmann (physicist) Annalen der Physik Integrated Authority File
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