Nitrogen dissociation atoms

It has been proposed that this reaction intermediate could decompose to produce HCN and CH3 [55], Chemiluminescence from alkanes can be greatly enhanced by addition of HC1. The proposed explanation is that energy transfer from active nitrogen dissociates HC1 to produce chlorine atoms, which have rapid hydrogen-atom abstraction reactions with alkanes,... 

The (at least approximate) validity of Eqs. (6.12)-(6.14) is clearly demonstrated by the remarkable quality of intrinsic CN bond energies and of bond dissociation energies calculated by means of nitrogen net atomic charges deduced in this manner. 

I. Langmuir, A. Eucken, and E. J. B. Willey and E. K. Rideal, the heat of dissociation of nitrogen into atoms N2=2N is greater than 190,000 cals, and probably of the order 300,000-400,000 cals, per mol. M. Saha believed this value to be much too high. W. Kuhn gave 140 Cals., H. D. Smyth, 145 Cals. 

The two phase model describes all the principle features of the desorption kinetics, suggesting that recombinative desorption under conditions where the coverage is less than saturation occurs by the recombination of N atoms from a dilute phase on the Cu(l 11) surface. This behaviour is the same as that observed for H recombinative desorption on many surfaces [63]. Desorption from the dilute phase is preferred over direct decomposition of the nitride islands because this leaves the copper surface in its equilibrium (111) orientation, rather than as an unstable Cu(l 00) overlayer [99]. As a result we expect that detailed balance can be used to relate measurements of recombination from the N covered Cu(l 1 1) surface with nitrogen dissociation on bare Cu(l 1 1) terraces. In contrast, if desorption occurred via decomposition of reconstructed copper nitride islands then detailed balance arguments would not reveal anything about the energetics or dynamics of N2 dissociation on a Cu(l 1 1) surface. 

Nitrogen atoms or radicals form N—H bonds. Nitrogen ( S) atoms, from N2 dissociation in an electrical discharge, react" with alkanes to form NH3 ... 

The existence of dissociated atoms has been demonstrated for hydrogen or nitrogen on the surface of metallic catalysts by means of isotopic... 

The nucleic bases are all weak acids with pk values from 10 to 12. NH protons of imidazole N9 or of the lactam nitrogens dissociate by 50% at pH 10-12. Mercury or silver salts react with these nitrogen atoms to form salts (Scheme 8.5.3). Nucleosides are formed if the mercury or silver salts are combined with halosides of deoxyribose. 

A completely different strategy for the surface functionalisation of CNTs with nitrogen-containing groups is the treatment of CNTs under atomic nitrogen flow obtained by molecular nitrogen dissociation in an Ar -t N2 microwave plasma. X-ray photoelectron spectroscopy of the nanotube surface demonstrated the presence of amides, oximes and mainly amine and nitrile groups. ... 

On the other hand, it is also quite important to study reaction kinetics in nitrogen plasmas to understand quantitative amount of various excited species including reactive radicals. Many theoretical models have been proposed to describe the number densities of excited states in the plasmas. Excellent models involve simultaneous solvers of the Boltzmann equation to determine the electron energy distribution function (EEDF) and the vibrational distribution function (VDF) of nitrogen molecules in the electronic ground state. Consequently, we have found noteworthy characteristics of the number densities of excited species including dissociated atoms in plasmas as functions of plasma parameters such as electron density, reduced electric field, and electron temperature (Guerra et al, 2004 Shakhatov Lebedev, 2008). 

The estimated maximum probability of Hg dissociation is P 0.1 [295]. It can be concluded from the various electron energies measui ed that the excitation function of the level has a maximum at 8.8 eV, close to the threshold of excitation. This corresponds to the most probable transition according to the Franck-Condon principle (Fig. 39). The threshold of molecular nitrogen dissociation has been found [335] to be 9.6 i 0.05 eV, a value virtually coinciding with the Ng dissociation energy (9.76 eV). (Concerning electron impact excitation of atoms and molecules see e.g. [181, 441].)... 

Now, it is generally accepted that the dissociated adsorption of N2 is the rate determining step, because it has been confirmed by many results from surface science experiments. The contradictions about the pathway of nitrogen dissociation adsorption still remains, as different conclusions were obtained from different experimental measures. Meanwhile, there are also different results for different metals and crystal faces under various experimental conditions. Some experiments showed that N2 was dissociated directly to nitrogen atoms on Fe sm-face, and others found that N2 were dissociated to nitrogen atoms by intermediates, based... 

A study of the reaction N, + 3H, - 2NH" used for the industrial production of ammonia, reveals that the rate of this reaction is actually controlled by the rate at which nitrogen dissociates into atomic nitrogen. Thus, anything that increases the rate ofthe reaction N, - 2N automatically will increase the production rate of ammonia. This also reveals the most important point in the study of reaction mechanisms When a reaction proceeds through more than one step, the slowest one determines the rate ofthe overall reaction and therefore determines the observed rate equation. The slowest step, the bottleneck in the series, is said to be rate determining. These ideas may be illustrated by the following analogy ... 

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