Discovery nitrogen

The study of the atmosphere led to the discovery of nitrogen. Although it is associated with the name of a certain scientist and a certain date, this certainty is misleading. It is rather difficult to separate the history of nitrogen discovery from the mainstream of pneumatic chemistry one can only think of a more or less logical sequence of events. 

Our experience conditions us to focus on the organic components of the reaction—l arginine and l citrul line—and to give less attention to the inorganic one—nitric oxide (nitrogen monoxide NO) To do so however would lead us to overlook one of the most important discoveries in biology in the last quarter of the twentieth century... 

Almost as soon as Pedersen announced his discovery of the crown ethers (see Chaps. 2 and 3) it was recognized by many that these species were similar to those prepared by Busch and coworkers for binding coinage and transition metals (see Sect. 2.1). The latter compounds contained all or a predominance of nitrogen and sulfur (see also Chap. 6) in accordance with their intended use. The crown ethers and the polyazamacrocycles represented two extremes in cation binding ability and preparation of the intermediate compounds quickly ensued. In the conceptual sense, monoazacrowns are the simplest variants of the macrocyclic polyethers and these will be discussed first. 

Discovery of a nitrogen isotope N by S. M. Naudd following the discovery of isotopes of O and C by others earlier in the same year. 

A number of nitrogen-fixing bacteria contain vanadium and it has been shown that in one of these, Azotobacter, there are three distinct nitrogenase systems based in turn on Mo, V and Fe, each of which has an underlying functional and structural similarity.This discovery has prompted a search for models and the brown compound [Na(thf)]+[V(N2)2(dppe)2] (dppe = Pli2PCH2CH2PPh2) has recently been prepared by reduction of VCI3 by sodium naphthalenide... 

Finally, in 1797, the Frenchman L. N. Vauquelin discovered the oxide of a new element in a Siberian mineral, now known as crocoite (PbCr04), and in the following year isolated the metal itself by charcoal reduction. This was subsequently named chromium (Greek xpco ia, chroma, colour) because of the variety of colours found in its compounds. Since their discoveries the metals and their compounds have become vitally important in many industries and, as one of the biologically active transition elements, molybdenum has been the subject of a great deal of attention in recent years, especially in the field of nitrogen fixation (p. 1035). 

Knorr reported the first pyrazole derivative in 1883. The reaction of phenyl hydrazine and ethylacetoacetate resulted in a novel stmcture identified in 1887 as l-phenyl-3-methy 1-5-pyrazolone 9. His interest in antipyretic compounds led him to test these derivatives for antipyretic activity which led to the discovery of antipyrine 10. He introduced the name pyrazole for these compounds to denote that the nucleus was derived from the pyrrole by replacement of a carbon with a nitrogen. He subsequnently prepared many pyrazole analogs, particularly compounds derived from the readily available phenyl hydrazine. The unsubstituted pyrazole wasn t prepared until 1889 by decarboxylation of liT-pyrazole-3,4,5-tricarboxylic acid. ... 

Since the discovery of buckminsterfullerene (C o) [85NAT(318)162] and other fullerenes (Cig. C70), these molecules have been intensely studied, both experimentally and theoretically. Likewise, several reports on heterofullerenes containing heteroatoms such as nitrogen and boron have appeared (91JPC4948 91JPC10564). The incorporation of heteroatoms is expected to modify the structural and electronic features of these structures, and have thus attracted some interest. 

The adventitious discovery of the antitumor action of the nitrogen mustard poison war gases led to intensive investigation of the mode of action of these compounds. In brief, it has been fairly well established that these agents owe their effect to the presence of the highly reactive bis(2-chloroethyl)amine group. The cytotoxic activity of... 

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