Near discovery

The mngsten ore called scheehte is named after Carl Wilhelm Scheele (1742—1786), who smdied and experimented with tungsten minerals, but as with many of his other near discoveries, such as oxygen, fluorine, hydrogen sulfide, hydrogen cyanide, and manganese, he was not given credit. 

G. B. Kauffman, I. Bernal and H.-W. Schiitt, Overlooked opportunities in stereochemistry, Part IV. Eilhard Mitscherlich s near discovery of conglomerate crystallization on the sesquicentennial of Pasteur s resolution of sodium ammonium racemate , Enantiomer, 1999, 4, 33—45. 

Of all the work described in this thesis, this discovery is probably the most significant. Given the fact that the arene - arene interactions underlying the observed enantioselectivity of ftie Diels-Alder reactions described in Chapter 3 are also encountered in other organic reactions, we infer that, in the near future, the beneficial influence of water on enantioselectivity can also be extended to these transformations. Moreover, the fact that water can now be used as a solvent for enantioselective Lewis-add catalysed reactions facilitates mechanistic studies of these processes, because the number of equilibria that need to be considered is reduced Furthermore, knowledge and techniques from aqueous coordination chemistry can now be used directly in enantioselective catalysis. 

The discovery of chemical N2 fixation under ambient conditions is more compatible with a simple, complementary, low temperature and low pressure system, possibly operated electrochemically and driven by a renewable energy resource (qv), such as solar, wind, or water power, or other off-peak electrical power, located near or in irrigation streams. Such systems might produce and apply ammonia continuously, eg, directly in the rice paddy, or store it as an increasingly concentrated ammoniacal solution for later appHcation. In fact, the Birkeland-Eyde process of N2 oxidation in an electric arc has been... 

Vanadium was first discovered in 1801 by del Rio while he was examining a lead ore obtained from Zimapan, Mexico. The ore contained a new element and, because of the red color imparted to its salts on heating, it was named erythronium (redness). The identification of the element vanadium did not occur until 1830 when it was isolated from cast iron processed from an ore from mines near Taberg, Sweden. It was given the name vanadium after Vanadis, the Norse goddess of beauty. Shordy after this discovery, vanadium was shown to be identical to the erythronium that del Rio had found several years eadier. 

Some years after Davy s death, Faraday examined the corrosion of cast iron in sea water and found that it corrodes faster near the water surface than deeper down. In 1834 he discovered the quantitative connection between corrosion weight loss and electric current. With this discovery he laid the scientific foundation of electrolysis and the principles of cathodic protection. 

Tellurium was the first of these three elements to be discovered. It was isolated by the Austrian chemist F. J. Muller von Reichenstein in 1782 a few years after the discovery of oxygen by J. Priestley and C. W. Scheele (p. 600), though the periodic group relationship between the elements was not apparent until nearly a century later (p. 20). Tellurium was first... 

The lanthanides comprise the largest naturally-occurring group in the periodic table. Their properties are so similar that from 1794, when J. Gadolin isolated yttria which he thought was the oxide of a single new element, until 1907, when lutetium was discovered, nearly a hundred claims were made for the discovery of elements... 

Despite the synthetic utility of this transformation, nearly eighty years elapsed between the discovery of the Bischler-Napieralski reaction and the first detailed studies of its mechanism. " Early mechanistic proposals regarding the Bischler-Napieralski reaction involved protonation of the amide oxygen by traces of acid present in P2O5 or POCI3 followed by electrophilic aromatic substitution to provide intermediate 5, which upon dehydration would afford the observed product 2. However, this proposed mechanism fails to account for the formation of several side products that are observed under these conditions vide infra), and is no longer favored. 

In 1921, Irene Curie (1897-1956) began research at the Radium Institute. Five years later she married Frederic Joliot (1900-1958). a brilliant young physicist who was also an assistant at the Institute. In 1931, they began a research program in nuclear chemistry that led to several important discoveries and at least one near miss. The Joliot-Curies were the first to demonstrate induced radioactivity. They also discovered the positron, a particle that scientists had been seeking for many years. They narrowly missed finding another, more fundamental particle, the neutron. That honor went to James Chadwick in England. In 1935,... 

Furchgott and Zawadzki [1] first discovered that endothelial cells release a substance(s) responsible for the relaxation of vascular smooth muscle by acetylcholine this substance was named endothelium-derived relaxing factor (EDRF). This epoch-making discovery answers the question raised for nearly one hundred years by pharmacologists about why vascular smooth muscle is relaxed by acetylcholine, which however elicits contraction of the other smooth muscles. Because of its instability, the true chemical nature of EDRF was not easily identified. Several years later, several research groups independently found that the biological activities and biochemical properties of EDRF were identical... 

In these developments there were two distinct stages the first one, which dealt with the nearly linear oscillations, found its perfect algorithm in the theories of Poincare (both topological and analytical), which constitute the major part of this review here the discoveries were most striking as well as systematic. Numerous phenomena that had remained as riddles for many years, sometimes even for centuries, were systematically explained. We indicate in Part I of this chapter the qualitative aspect of this progress and in Part II, the quantitative one. 

Indeed it can be stated that the history of modern expls begins with the discoveries of nitroglycerin (NG) and nitrocellulose (or more correctly cellulose nitrate or NC) nearly 125 years ago, and their application to military and commercial usage. An excellent review of the early history of NC is given by. T.L. Davis (Ref 29, pp 244—56). The early histories of NG and EGDN (discovered in 1870) are summarized, respectively, in Vol 6, G99-R to G100-R and E259-R, and in the Naoum reference cited above... 

Nearly 25 years after its discovery the mechanism of the benzannulation reaction has been theoretically and experimentally elucidated in detail. The most predominant outcome of this reaction is the formation of the 4-methoxyphe-nol or 4-methoxy-l-naphthol skeleton coordinated to a Cr(CO)3 fragment. Therefore the mechanism leading to this type of product will be discussed first. 

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