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 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 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 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 azabicyclospirohydantoins

The mass spectra of some N-substituted nortropane and granataninespirohydantoins are compared with those of N-substituted 3-azabicyclo[3.2.1]octane-8-spiro-, 3-azabicyclo[3.3.1]nonane-9-spiro-, 8-azabicyclo-[4.3.1]decane-10-spiro- and 3,7-diazabicyclo[3.3.1]nonane-9-spiro-5′-hydantoins. Mass spectra data of monothio- and dithio-tropanespirohydantoins are also included. Mass fragmentation and structure relationships of these molecules have been established.     

氮杂硅三环类化合物的质谱研究

本文对二十四个氮杂硅三环类化合物进行了质谱研究.测定了它们的低分辨质谱,收集了大部分化合物的高分辨质谱数据并进行了亚稳跃迁测定。结果表明,分子离子的稳定性、基峰的生成方式以及碎片离子的多少主要取决于取代基R的性质.分子的电子轰击质谱裂解存在三种基本方式:(1)断裂Si～R键,生成高度稳定的(M-R)~ 离子,碎片离子较少;(2)开环,失去碎片C_2H_3O;(3)开环,失去碎片CH_2O或CH_3O.用电荷自由基定域理论解释这类化合物的质谱裂解机理,并对影响分子离子稳定性的有关因素及影响基峰形成的原因进行了讨论.     

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.     

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 several silanogermanes

Conclusions Rearrangement processes are found for the fragmentation of organosilanogermanes upon electron impact accompanied by the migration of alkyl groups or hydrogen atoms as well as substituent exchange between the silicon and germanium atoms. The Ge-Ge bonds in silanogermanes are less stable toward electron impact than the Si-Ge bonds.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1668–1670, July, 1987.