Nitrogen atmospheric reactions involving

The chemical transformations occurring in the atmosphere are best characterized as oxidation processes. Reactions involving compounds of carbon (C), nitrogen (N), and sulfur (S) are of most interest. The chemical processes in the troposphere involve oxidation of hydrocarbons, NO, and SO2 to... 

Chemical reactions involving aerosol particles in the atmosphere derive from the interaction of gaseous species with the liquid water associated with aerosol particles and with dissolved electrolytes. For example, the generation of HONO from nitrogen oxides... 

In the early 1950 s, it was reported by Haagen-Smit that many of the characteristics of photochemical smog could be explained by the presence of ozone and other photochemical oxidants. These substances, he believed, were formed in the atmosphere as a result of chemical reactions involving nitrogen oxides and hydrocarbons present in automobile exhaust. Significant quantities of nitrogen oxides were also emitted by power plants. 

Surface Chemical Analysis. Electron spectroscopy of chemical analysis (ESCA) has been the most useful technique for the identification of chemical compounds present on the surface of a composite sample of atmospheric particles. The most prominent examples Include the determination of the surface chemical states of S and N in aerosols, and the investigation of the catalytic role of soot in heterogeneous reactions involving gaseous SO2, NO, or NH3 (15, 39-41). It is apparent from these and other studies that most aerosol sulfur is in the form of sulfate, while most nitrogen is present as the ammonium ion. A substantial quantity of amine nitrogen also has been observed using ESCA (15, 39, 41). 

However, linear 68a was a major product (59%) with the concomitant formation of 65 a (20%) in the reaction of 63 a with two molar equivalents of BuMe2SiH at 25 °C (Scheme 6.13, mode 2) [20 a]. Based on these results, the formation of 64 and 65 is thought to involve the intermediacy of 70 and 71. This idea is supported by the fact that catalyst 72, prepared in situ by the interaction of RhCl(PPh3)3 with a molar equivalent of R3SiH, selectively formed 69 as the major product in the reaction of 63 with R3SiH under a nitrogen atmosphere (Scheme 6.13, mode 3) [21]. When Rh4(CO)i2 was used as a catalyst instead of 72, 69 was obtained as a minor component along with... 

A preparative method similar to the Castner process for the production of sodium cyanide involves adding red-hot charcoal slowly to molten potassium in a steel vessel. The mixture is heated to about 750°C and then ammonia is introduced gradually. The fused product is pumped to a filter furnace at high tempeature where the molten potassium cyanide is filtered in a nitrogen atmosphere. The overall reaction for the process is ... 

Sulfiirization of unsaturated compounds and mercaptans is normally carried out at atmospheric pressure, in a mild or stainless steel, batch-reaction vessel equipped with an overhead condenser, nitrogen atmosphere, an agitator, heating media capable of 120—215°C temperatures and a scrubber (typically caustic bleach or diethanolamine) capable of handling hydrogen sulfide. If the reaction involves the use of H2S as a reactant or the olefin or mercaptan is a low boiling material, a stainless steel pressurized vessel is recommended. 

All reactions involving catalyst preparations were carried out under an atmosphere of prepurified nitrogen or argon in previously dried equipment. IR spectra were obtained on a Perkin-Elmer model 621 or model 257 spectrometer. The IR cells were of the sealed cavity type (<—- 100//,) with Teflon stoppers. Four types of cell window materials were used As2S3, KBr, Irtran 2, and Ge metal. The spacers were Teflon except for the KBr cell in which lead was used. Analyses were performed by Phillips Research Division. 

The synthetic strategy of unsymmetrical BTE-TAPs involved the co-cyclization of bis(3-thiophenyl)maleonitrile and 1,2-dicyanobenzene in different molar ratios under nitrogen atmosphere in the dark, as was described in Scheme 10. Magnesium was a template to gain the unsymmetrical macrocycles. The preparation of the symmetrical phthalocyanine hybrids began with the reaction of magnesium powder... 

A Study of Leaching of the Infiltrated Concrete. The distilled water experiments provided the most information for examining the reactions involved in the leaching of sulfur-infiltrated concrete in aqueous media. Products selected from the specimens were analyzed, and the experiment was continued in a controlled environment. One specimen was partly immersed in distilled water under a nitrogen atmosphere. Fragments of the concrete were also sealed in a test tube. 

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