Chemical Education Today
Anniversaries: 2000 by Paul F. Schatz 1800 (200 years ago)
trogen content of organic compounds. In his method, samples are initially digested with concentrated sulfuric acid in a specially designed flask. The technique was developed by Kjeldahl while he was working at the Carlsberg Laboratory for fermentation research. {1934, 11, 457; 1949, 26, 459} Peter Waage, Norwegian chemist, died Oslo, January 13. Waage developed the law of mass action with Cato Maximilian Guldberg. {1965, 42, 548}
William Henry Fox Talbot, born February 11. Talbot invented a photographic method similar to that of Daguerre. Talbot's method had the advantage that multiple copies of an image could be made from the original photograph. {1927, 4, 298} Jean Baptiste Dumas, born July 14. French chemist who advanced the “type” theory of organic chemistry. {1951, 28, 630} Friedrich Wöhler, born July 31. 1950 (50 years ago) German chemist who synthesized urea Sir Walter Norman Haworth, English from an inorganic substance, thus unchemist, died Birmingham, March 19. dercutting the idea that organic chemiPhotograph of William Henry Fox Haworth worked on the structure of sugcals required a “vital force” for their Talbot. {1927, 4, 306} ars. For his work on vitamins, particularly synthesis. {1928, 5, 1539; 1955, 32, vitamin C, he shared the 1937 Nobel Prize 403; 1957, 34, 141; 1964, 41, 452} in Chemistry with Paul Karrer. {1926, 3, Charles Goodyear, born Decem1416; 1934, 11, 69; 1935, 12, 429} ber 29. American inventor who discovered a method of heatRichard Kuhn, German chemist, born December 3. treating rubber with sulfur (vulcanization) that improved Kuhn was awarded the 1938 Nobel Prize in Chemistry for rubber's physical properties. his work on vitamins. His group carried out the Herculean labor of isolating vitamin B-6 from 14,000 gallons of skim 1900 (100 years ago) milk. {1933, 10, 343} Frederic Joliot-Curie, born March 19. Frederic, working with his wife, Irene Curie, discovered that new, radioactive elements could be created by bombarding elements with Other Historical Events alpha particles. Bombarding aluminum foil with alpha particles formed an isotope of phosphorus, which further de1800 (200 years ago) cayed to silicon. This work laid the ground work for nuclear Chemistry at the start of the 19th century was profusion and the creation of superheavy, transuranium elements foundly affected by the development of the Voltaic pile by by Seaborg and others. Alessandro Volta. It provided the first source of constant elec27 4 30 1 30 0 tric current. {1991, 68, 665; 1927, 4, 770} Al + He → P + n → Si + e 13 2 15 0 14 +1 The Voltaic cell was almost immediately put to use by William Nicolson and Anthony Carlisle to split water into Sir Hans Krebs, born August 25. Krebs elucidated the its elements, oxygen and hydrogen. This electrolysis process manner in which sugars, fats, and proteins are metabolized was the reverse of what had been demonstrated several years by living organisms to produce energy (Krebs’s cycle). He before, the combination of oxygen and hydrogen to form shared the 1953 Nobel Prize for physiology and medicine water. with Fritz Lipmann. {1986, 63, 673} In 1800 the Royal Institution was founded in London Wolfgang Pauli, born April 25. Pauli, a by Count Rumford. The purpose of the institution was to brilliant theoretical physicist, received the 1945 educate the public through public lectures. It also carried out Nobel Prize in physics. At the age of 25, Pauli scientific researches with practical objectives. had developed the exclusion principle, e.g., each The construction of a large Voltaic pile in the Royal Inenergy level of electrons within an atom could stitution provided electricity for extensive electrochemical be occupied by two, and only two, electrons and investigations by Humphry Davy in the early 19th century. the electrons must have the opposite spin. In These investigations would lead to the discovery of many el1931, Pauli predicted the neutrino (named such by Enrico Fermi) to explain anomalous energy loss in beta particle emission. It was not until 1956 that his postulated particle was finally deAt the end of some of the anniversaries are references tected. {1950, 27, 2; 1981, 58, 273} to J. Chem. Educ. papers {year, volume, page} which are Johann Gustav Kjeldahl, Danish chemist, relevant to the topic or person. died Tisvildeleje, July 18. Kjeldahl developed an K j e l d a h l improved, rapid method for determining the ni- flask. JChemEd.chem.wisc.edu • Vol. 77 No. 1 January 2000 • Journal of Chemical Education
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Chemical Education Today
Anniversaries: 2000 ements, including sodium, potassium, barium, and strontium. {1985, 62, 397} However, at the start of the 19th century, Humphry Davy was busy preparing and testing gases, including the effect of inhaling them. In 1800 he discovered that inhaling nitrous oxide (N 2 O, dinitrogen monoxide), produced a euphoric state. This “laughing gas” proved to be exA Voltaic pile is created from a tremely popular in pubstack of alternating zinc and lic demonstrations at copper (or silver) disks sepathe Royal Institution. rated by felt soaked with salt soIn 1800, William lution. Cruickshank used chlorine to purify water. One hundred years later in 1900, chlorine was used by Woodhead to disinfect the water supply of Maidstone, England, after a typhoid epidemic.
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1900 (100 years ago) In 1900, the discovery and isolation of naturally occurring, radioactive elements continued with the isolation of an inert, radioactive gas, radon, by Friedrich Dorn. The discovery of “artificial radioactivity” would have wait for Frederic Joliot-Curie and Irene Curie in the 1930s. On the theoretical front, Max Planck was able to derive an equation that accounted for the distribution of wavelengths in black body radiation by assuming that radiation of frequency ν must have an energy that is an integer multiple of hν, where h is a constant that is the same for all frequencies. This was the first step towards the foundation of quantum theory. {1963, 40, 262} Organic chemists were busy exploring the structures of organic compounds and learning to control the course of chemical reactions of organic compounds. Moses Gomberg, working on the synthesis of hexaphenylethane, created a compound that reacted as if it was a triphenylmethyl radical. Later work demonstrated that the actual structure of the compound was as shown below. Gomberg is credited with the discovery of the first stable free radical. {1932, 9, 439} Ph Ph
Ph Ph
Ph
H
Structure of compound that Gomberg synthesized.
Journal of Chemical Education • Vol. 77 No. 1 January 2000 • JChemEd.chem.wisc.edu
Chemical Education Today
Vladimir Ipatieff discovered that reactions could be profoundly influenced by the nature of the materials with which they were in contact, such as walls of reaction vessels. This led to his extensive investigation of the effect of catalysts on high temperature (and pressure) reactions. On the biochemistry front, Frederic G. Hopkins and S. W. Cole isolated tryptophan and demonstrated that it is an essential nutritional ingredient in the diet of mice. This ignited the study of dietary requirements, which eventually led to the discovery of vitamins and other essential substances and to cures for diseases such as scurvy, rickets, and beriberi. Hopkins received the 1929 Nobel Prize in Medicine and Physiology.
Cyclamate, a compound with about 30 times the sweetening power of sucrose, was introduced as an artificial sweetener. In the sixties, tests indicated that cyclamates were carcinogenic and their use was curtailed. More recent tests have not substantiated this and have led to the reconsideration of the prohibition of cyclamate use. Structure of cyclamic acid.
Ipatieff developed a high pressure bomb which became the “test-tube” of high pressure chemists. {1937, 14, 553}
1950 (50 years ago)
Berkelium, the first transuranium element, was prepared by a group led by Glenn Seaborg, by bombarding an americium target with high energy helium ions. Shortly thereafter, bombardment of a curium target with high energy helium ions produced californium. Glenn Seaborg shared the 1951 Nobel Prize in Chemistry with William McMillan. {1959, 36, 32} 241 95Am 96
Cm242
+ 2He4 → +
2
He4
→
97Bk 98
243
Cf 245
0
H
O O HO2C
H2N
O CH2 C CH2 CH2
O O C NH2
CH3
O
O
C
n1
The 1950 Nobel Prize in Chemistry was awarded to Otto Diels and Kurt Alder for their discovery and extensive study of the formation of substituted cyclohexene compounds from dienes and olefins. This method has proved to be one of the most powerful tools available for synthesizing compounds in a stereospecific manner.
+
CH3
O
CH2
+ 2 0 n1 +
Two views of the structure of Milltown, a meprobamate that comes into wide use as a tranquilizer.
H HO2C
This example is the initial step in the total synthesis of reserpine reported by R. B. Woodward in 1956. {1933, 10, 494}
The 1950 Nobel Prize in Medicine and Physiology was awarded to P. S. Hench, E. C. Kendall, and T. Reichstein for their work with hormones, such as cortisone.
In 1950, clinical research on extracts from the Indian snake-root plant, Rauwolfia serpentina, was initiated in America by the physician Robert W. Wilkins. His interest in Rauwolfia was sparked by an article by a doctor from India, R. J. Vakil published in 1949 in the British Heart Journal describing the antihypertensive properties of extracts of Rauwolfia. Extracts of Rauwolfia were a popular Indian folk medicine and were purported to relieve everything from cholera to snake bite to the common cold. Wilkins’ studies, reported in 1952, confirmed the remarkable antihypertensive activity of Rauwolfia. The isolation of the active principle of Rauwolfia was reported in 1952 by E. Schlittler, J. Müller, and H. J. Bein of CIBA Laboratories in Basle, Switzerland. A crystalline compound, named reserpine, was isolated from the “brown, muddy residue” left after isolation of several other crystalline products. The residue was examined because pharmacological testing indicated that the major activity was in the goo, not in the isolated crystalline materials. CIBA eventually marketed the purified reserpine under the name of Serpasil.
JChemEd.chem.wisc.edu • Vol. 77 No. 1 January 2000 • Journal of Chemical Education
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Chemical Education Today
Anniversaries: 2000 Reserpine exhibits a multitude of physiological activities including a potent tranquilizing action. In 1954, a study showed that reserpine dramatically reduced tensions of manic depressive and schizophrenic patients. Reserpine was widely prescribed in psychiatric therapy. It was once the great hope for curing depression, but has since been replaced by other, more effective drugs. Reserpine use in treating hypertension has also been supplanted by newer drugs. H3CO H N
N The first step of the total synthesis of reserpine reported by R. B. Woodward in 1956 used a Diels-Alder reaction to establish the relative stereochemistry at three stereocenters of the final product. These centers are highlighted in the structure drawing.
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Indian snake root.
H
H
O H HO2C
OCH3
O OCH3
OCH3 OCH3
Journal of Chemical Education • Vol. 77 No. 1 January 2000 • JChemEd.chem.wisc.edu
