Ethylene nitrogen fixation

Coucouvanis, D., Mosier, P.E. Malinak, S. Laughlin, L. Demadis, K.D. (1995) Catalytic reduction of hydrazine and acetylene to ammonia and ethylene and stoichiometric reduction of CN to ammonia and methane by Fe/M/S clusters (M =Mo, V) with structural features similar to those of the Fe/Mo/S site in nitrogenase, Plant Sci. Biotechnol. Agric. (Nitrogen Fixation Fundamentals and Applications) 27, 137-42. 

Iron is important in plants not only because of its role in fundamental processes such as photosynthesis, respiration, nitrogen fixation, and DNA synthesis, but also because of its involvement in key enzymes of plant hormone synthesis, such as lipoxygenases and ethylene-forming enzymes. Despite the fact that iron represents 4—5% of the total solid mineral composition of soils, it is generally present in soils in a poorly soluble form, and... 

It is interesting, that the substrate specificity of nitrogenases is low in comparison with other enzymes. They also reduce acetylene (to ethylene), hydrazine [39], cyanide and azide. [40] From this, and from the presumably very high biological age of the enzyme system, W. S. Silver and John R. Postgate [41 ] con-duded that the enzyme s original purpose was not nitrogen fixation, but cyanide detoxification in the biosphere of Precambrian bacteria. 

Activity of N. preparations is usually measured by colorimetric assay of ammonia, following incubation with molecular nitrogen. Nitrogen fixation in general can be determined from the incorporation of N2 into cell material, but the method is relatively expensive and tedious. The use of acetylene (ethyne) as an alternative substrate of N. has revolutionized studies of nitrogen fixation. Assays are performed in a closed system. The product ethylene (ethene) is not assimilated and is easily assayed by gas chromatography. 

Hardy, R. W. F., Holsten, R. D., Jackson, E. K., and Burns, R. C. (1968). The acetylene ethylene assay for nitrogen fixation. Laboratory and field evaluation. Plant Physiol. 43, 1185-1207. 

GROBELAAR N., CLARKE B., HOUGH M.C. 197". The nodulation and nitrogen fixation of isolated roots of Phaseolus vulgaris L. III. The effect of carbon dioxide and ethylene. Plant and Soil Special Volume, pp. 215-221. 

G) Miscellaneous reactions, e.g. the oxidation of ethylene to acetaldehyde, some reactions catalysed by copper and nitrogen fixation. 

It is clear from these experiments that the presence of ethylene catalyses the fixation of nitrogen in lithium complexes. This assisted complexation was also observed with methyl-substituted ethylene and butadiene. It is a characteristic property of lithium-alkene complexes, as experiments performed with other lithium complexes have so far not yielded such ternary complexes. If one can easily anticipate that the fractional positive charge on the lithium in LiC2H4 and Li(C2H4)2 facilitates the coordination of N2 with, presumably, a a-donation to lithium, and possibly, to a weaker extent, p-donation from the metal, it is difficult to rationalize why LiC2H2 and LiC2H4 behave so differently with respect to nitrogen, for instance. 

Figure 17.14. Some unusual reactor configurations, (a) Flame reactor for making ethylene and acetylene from liquid hydrocarbons [Patton et al., Pet Refin 37(li) 180, (1958)]. (b) Shallow bed reactor for oxidation of ammonia, using Pt-Rh gauze [Gillespie and Kenson, Chemtech, 625 (Oct. 1971)]. (c) Sdioenherr furnace for fixation of atmospheric nitrogen, (d) Production of acetic acid anhydride from acetic acid and gaseous ketene in a mixing pump, (e) Phillips reactor for low pressure polymerization of ethylene (closed loop tubular reactor), (f) Polymerization of ethylene at high pressure.

Nadar, Paris). Founder of thermochemistry and the science of explosives. He synthesised acetylene and bensene from their elements, and alcohol from ethylene, studied the polyatomic alcohols and acids, the fixation of nitrogen, the cbemistiy of agriculture, and the history of Greek, Syriac, Arabic, and medieval chemistry. He was a Senator of France, Minister of Public Instruction, Minister of Foreign Affairs, and Secretary of the Academy of Sciences, and is buried in the Pantheon at Paris. 

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