Mass spectra of the bromofluorocyclotriphosphazenes

The mass spectra of geminal-, cis- and trans--bromofluorocyclotriphosphazenes (N₃P₃Br_nF_6−n, n = 2–5) have been obtained at an electron energy of 70 eV. When n = 2 or 3 there is a substantial difference between the geminal and non-geminal isomers for the process involving loss of a bromine atom from the parent ion. When n = 2–4 there is a distinction between the types of linear ions formed from geminal and non-geminal isomers. Cis- and trans-isomers could not be distinguished. The relative proportions of cyclic and linear ions are discussed. Groups of partially resolved ions were observed resulting from the decomposition of isotopically related metastable ions. Several new types of metastable transition were observed.     

Bitter principles of Picrasma ailanthoides planchon: Nigakilactones J,K, L,M and N

Five new crystalline bitter principles were isolated from the stem-chips of Picrasma ailanthoides Planchon (Simaroubaceae). Structures of nigakilactones J, K, L, M and N were shown to be 1a, 2a, 3d, 4c and 4b, respectively.     

Mass spectra of benzenesulfonylhydrazides

The mass spectrometry of substituted benzenesulfonylhydrazides (X.C₆H₄.SO₂NHNH₂) has been studied, with X = p-CH₃, H, p-CH₃O and p-Br. The intensities of [X? C₆H₄SO₂]⁺ and [X? C₆H₄]⁺ follow the Hammett relationship [In(Z/Z₀) =ρδp⁺] with ρ of 0.375 and 2.37, respectively.     

Mass spectra of o-aminobenzophenones

The electron impact induced fragmentation of chlorine substituted o-aminobenzophenones has been examined. All the compounds show ions formed by α-cleavage on either side of the carbonyl group. The relative intensity of the resulting ions is predictable from the quasi-equilibrium theory. The most important features of the mass spectra of these compounds are, however, intense [M? H]⁺ ions for the primary amines and [M – OH]⁺ ions for the N-methylated compounds. These and other less intense peaks as well as some metastable ions allows structural elucidation.     

Mass spectra of C-methylinositols

The mass spectra of C-methyl-inositols and of two of their deuterium-labelled analogues have been studied. The results indicate that each stereoisomer can be characterized by its mass spectrum. A fragmentation scheme based upon high-resolution measurements, metastable peaks and deuterium-labelling is proposed.     

Mass spectra of the substituted quinuclidines

The mass spectra of the quinuclidine-2 (and -3)-ones and other functional derivatives of quinuclidine as well as 2-azaquinuclidine and benzoquinuclidine have been investigated. The fragmentation through the open form of the molecular ion and the applicability of Bredt's rule to amine fragmentation of the bridgehead nitrogen bicyclic systems are discussed.     

Mass spectra of dimethylpyrimidines

The mass spectra of the four dimethylpyrimidines are compared with those of the isomeric dimethylpyrazines. It was necessary to synthesise three of the dimethylpyrimidines, and methods are described.     

Mass spectra of thiazolidines

The electron impact mass spectra of twelve thiazolidines have been measured and the fragmentation patterns examined. The three most intense fragmentations common to all the thiazolidines examined are: (a) the cleavage of the substituent at C-2, (b) 1,4-ring cleavage, and (c) 2,5-ring cleavage. The 1,4- and 2,5-cleavages occur with and without rearrangement of a proton.     

Mass spectra of azetidines

The mass spectra of azetidine, 2-methylazetidine, 2-phenylazetidine, methylene-bis-azetidines, their N-halo- and N-tosyl derivatives, 2-phenylazetine as well as N,N-dimethylmethane sulphonamide, N,N-dimethyl and N,N-diethyl- p-toluene sulphonamides have been investigated. The fragmentation of azetidine derivatives via the open form of the molecular ion is discussed.     

Mass spectra of arylalkylpyridines

The basic principles of the mass-spectral fragmentation of arylalkylpyridines that contain substituents in various positions were established. The principle ions that can be used in Chromatographic mass-fragmentographic analysis in the study of liquid-crystal compositions were determined for each specific case.Communication 1 of the series Mass spectra of liquid crystalsTranslated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1509–1513, November, 1987.     

Mass spectra of benzylpyridines

The mass spectra of dimethylbenzyl- and dimethyldibenzylpyridines at different ionizing electron energies were investigated. The anomalously low intensities of the molecular ion peaks of 3,4-dibenzylpyridines, as compared with the 2,5-isomers, and the greater probability of the formation of primary (M-2)⁺ ions in the mass spectra are explained by the synchronous loss of a neutral H₂ particle and the formation of cyclic fragment ions from the weakly excited molecular ions.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 70–73, January, 1973.     

Mass spectra of thiazoloquinolines

The behaviour under electron impact of sixteen thiazoloquinolines, unsubstituted and containing methyl substituents in both the pyridine and the thiazole rings, was investigated. Some decomposition schemes related to the main fragmentations in these fused heteroaromatic systems are proposed on the basis of available results on simpler related structures like thiazoles, benzo-thiazoles and quinolines.     

Mass spectra of N-arylaminosulphonylcarbethoxydiazoacetamides

The electron impact mass spectra of N-arylaminosulphonylcarbethoxydiazoacetamides were studied. On the basis of high-resolution mass spectrometric data, mass-analysed ion kinetic energy Spectrometry and linked scan experiments a detailed scheme of the fragmentation is proposed. A number of possibilities of charge Iocalization are revealed in the complex decomposition processes of the molecular ions.     

Mass spectra of aurones

The mass spectra are reported for 19 aurones (2-benzylidenecoumaran-3-ones) having a wide variety of functional groups and substitution patterns. The principal ions in these spectra are consistent with the operation of proximity effects demonstrated previously for 6-methoxyaurones.     

Mass spectra of aroylindoles

The data from low- and high-resolution mass spectrometry constitute evidence for nonidentical structures of the excited molecular ions of 2- and 3-aroylindoles, and this makes it possible to reliably identify isomeric pairs. The presence of rearranged (M-H-CO)⁺, (M-OH)⁺, and (M-H₂O)⁺ ions was noted, and a mechanism for their formation was proposed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 926–930, July, 1977.