Nitrogen thermochemistry

E. J. Prosen. Combustion in a Bomb of Compounds Containing, Carbon, Hydrogen, Oxygen, and Nitrogen. In Experimental Thermochemistry, vol. 1 F. D. Rossini, Ed. Interscience New York, 1956 chapter 6. 

A theoretical approach that we find predicts main-group thermochemistry quite successfully is the BAG method [67,72-74]. To date, BAG methods have been applied to and thermochemistry reported for compounds of boron [75,76], carbon [73,77], nitrogen [73], aluminum [76,78], sihcon [72,79-86], and galUiun [76]. The BAG methodology recognizes that... 

The behavior and reactivity of diimide can be understood best by considering the thermochemistry of hydrogenation of nitrogen ... 

Experimental Thermochemistry of Heterocycles and Their Aromaticity A Study of Nitrogen, Oxygen, and Sulfur Derivatives of Indane and Indene... 

Keywords aromaticity, indane, indene, nitrogen-containing heterocycles, oxygen-containing heterocycles, sulfur-containing heterocycles, thermochemistry... 

Finally, we note that all of the discussed heterocyclic derivatives of indane and indene have heteroatoms only in their five-membered ring. There are many other heterocycles related to indane that have the heteroatoms located elsewhere. However, the thermochemistry of such species is essentially uncharted. The enthalpy of formation of purine (XLVIII), with its four nitrogens dispersed through both rings, has been measured in recent times [78], and chronicled in the archive [15] with yet a later value [79], These two values inexplicably differ by over 2000 kJ mol-1. In the absence of a value for the enthalpy of sublimation we are hesitant to discuss this species further, other than to note two estimates from a paper more than 100 years old [80] that straddle the results in [78] by ca. 20 kJ mol-1. 

The mass spectra 7.98) thermochemistry 8-ioo) and photochemistry 98,101) of benzotriazoles have received considerable attention of late. In virtually every case the primary reaction is loss of nitrogen to give a di-radical which can equilibrate (by rearrangement) with arylnitrene, azepine, and cyanocyclopentadiene structures (50). There are differences between... 

Oxides of nitrogen and soot-related species are examples of chemical components present in very low concentrations in turbulent diffusion flames they are trace species. Trace species that maintain chemical equilibrium pose no special problems in that they may be handled directly by the methods of the preceding subsection. However, the trace species of interest often are far from equilibrium, as soot-related species always are and oxides of nitrogen almost always are. The fact that the concentrations of these species are low means that they affect the thermochemistry to a negligible extent and that finite-rate effects for them can therefore be analyzed more easily than those for major species. Methods of analysis have been developed in the literature [15], [27], [28], [82], [83]. Here we shall indicate how calculations of interest may be performed. 

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. 

The thermal and photolytic decomposition of hydrazine and substituted hydrazines and azines provide a source of many nitrogen containing radicals . For this reason a considerable amount of thermochemical data is now available relating to the bond energies of the bonds involved in these reactions. Friswell and Gowen-lock" have recently reviewed the chemistry and thermochemistry of nitrogen containing radicals, and the salient features of their article will serve as an introduction to this section. 

The isoelectronic principle, by which the chemistry of many nitrogen compounds can be related to that of their hydrocarbon counterparts can be useful if used with caution, e.g. account must be taken of the differences in the thermochemistry of the reactions involved s . A comparison of the bond dissociation energies in such isoelectronic sequences is instructive in this regard (Table 27) . 

Discussion of these compounds violates our premise of not having any heteroatom on the nitrogen atom. However, in that there is no Patai/Rappoport volume chapter, or any other review of the thermochemistry of hydroxylamines, we wanted to give these species a thermochemical home . 

Through these simulations, students appreciate the energetic and kinetic aspects of chemical reactions and why the composition of the atmosphere is critical to the outcome. For example, the class simulates the effect on the yield of amino acids if the atmospheric composition was CO2 instead of CH4 or the nitrogen source was N2 instead of NH3. The simulations also allow students to investigate the consequences if the pre-biotic atmosphere contained free 02. Through these simulations, basic chemical concepts are discussed including thermodynamics, thermochemistry and bond enthalpies, kinetics, and catalysis. 

Molecular structure and thermochemistry are interrelated here for species chosen from contributions to the earlier Volume 3 of this book series. Discussion includes halogenated species gaseous nonmetal dioxides X-Y bond-containing species (X,Y = C, N, O) small carbon molecules arenols and substituted arenes steroids aromatic carbocycles difluoramines and nitro compounds selenium- and tellurium-nitrogen compounds. 

The electron-transfer aspect of the reaction was studied by using Marcus theory and various thermodynamic cycles. Thus, the thermochemistries of a number of electron-transfer schemes were considered. Through a series of logical arguments, the scheme settled upon was not electron transfer per se but rather electrophilic attack of PAH by nitrosated nitrogen tetroxide ... 

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