Spectroscopy nitrogen containing compounds

Potthast, A., Schiene, R., and Fischer, K., Stmctural investigations of n-modified lignins by N-15-NMR spectroscopy and possible pathways for formation of nitrogen-containing compounds related to lignin, Holrforschung 50(6), 554—562 (1996). 

Rate constants for the reactions of OH radicals with n-nitroalkanes, n-alkyl nitrates and n-alkyl nitrites have been determined at 298 K and 1 atmosphere total pressure using both pulse radiolysis combined with kinetic spectroscopy and a conventional relative rate method. In order to provide more mechanistic information for these reactions, rate constants for the reaction of Cl atoms with these compounds were determined using the relative rate method. The data indicate that the reaction of OH radicals with these nitrogen-containing compounds involves both an abstraction and an addition channel. These results are discussed in terms of reactivity trends and compared with the data from the literature. 

I 8), the N chemical shifts of nitrogen containing compounds will appear with a minus or plus sign depending on whether they are shielded or deshielded with respect to nitromethane. This situation is not unique in NMR spectroscopy, since chemical shifts are also referenced with... 

Nitrogen-containing fulvalenes have not been systematically studied by mass spectroscopy. Only isolated data for several examples of compounds have been reported. Most of the data consist of electron impact (El) mass spectra recorded for analytical purposes. Only a minor fraction dealt with the characterization of ion structures or focused on the effects of substituents, the ring size of fulvalenes, or the number and arrangement of nitrogen atoms and the fragmentation pathways. 

Fig. 8.8 Structure of nitrogen containing heteroaromatic compounds that have been studied by INS spectroscopy, (a) pyridine [44], (b) pyridazine [45], (c) pyrimidine [46], (d) 2,4,5,6-tetrachloropyrimidine [47], (e) pyrazine [48], (f) j-triazine [48], (g) 1,3,5-trichloro-i-triazine [48] and (h) melamine [49].

The NMR spectra of imidoyl halides are not too well investigated. We have utilized NMR spectroscopy to elucidate the structure of arylsulfonyl-chloroformamidines ( ), but no data with regard to the chemical shift of alkyl groups attached to the carbon or nitrogen atom of the —C(X)=N— system is available. Of course, differentiation of the imidoyl halide structure in a-hydrogen containing compounds from the corresponding tautomeric enamine structures is easily accomplished by NMR spectroscopy, provided that the system contains olefinic protons. 

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