Mass Spectrometry of some Nuclear Substituted Styryl Ketones

1972 ◽  
Vol 50 (6) ◽  
pp. 871-879 ◽  
Author(s):  
P. J. Smith ◽  
J. R. Dimmock ◽  
W. G. Taylor
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectra ◽  
Aromatic Substitution ◽  
Fragmentation Pathways ◽  
Fragment Ions ◽  
Aliphatic Ketones ◽  
Decomposition Processes ◽  
Structure Formula ◽  
Related Compounds ◽  
Carbonyl Function

The mass spectra of a series of nuclear substituted styryl ketones with the structure[Formula: see text]and several relaTed compounds have been determined. The major fragmentation pathways include such processes as an aromatic substitution reaction occurring in the molecular ion as well as the McLafferty rearrangement. Only one of the two possible α-cleavages at the carbonyl function was observed. The major decomposition processes are outlined and compared with the recent results of a study on α,β-unsaturated aliphatic ketones. Mechanistic pathways are suggested for the formation of the major fragment ions.

Differentiation of the Isomeric o-(m- and p-) Nitro-(Chloro- and Bromo-)Benzyl-2,4-(and 2,1-) Disubstituted 2-Thiocytosinium Halides by Electron Impact Ionisation and Fast Atom Bombardment Mass Spectrometry

2009 ◽  
Vol 15 (4) ◽  
pp. 497-506 ◽  
Author(s):  
Tomasz Pospieszny ◽  
Elżbieta Wyrzykiewicz
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectra ◽  
Fast Atom Bombardment ◽  
Collision Induced Dissociation ◽  
Mass Measurements ◽  
Fragmentation Pathways ◽  
Mass Spectral ◽  
Fragment Ions ◽  
Accurate Mass Measurements ◽  
Impact Ionisation

Electron ionisation (EI) and fast atom bombardment (FAB) mass spectral fragmentations of nine 2,4-(and 2,1-) disubstituted o-( m- and p-)nitro-(chloro- and bromo-)-2-thiocytosinium halides are investigated. Fragmentation pathways, whose elucidation is assisted by accurate mass measurements and metastable transitions [EI-mass spectrometry (MS)], as well as FAB/collision-induced dissociation (CID) mass spectra measurements are discussed. The correlations between the abundances of the (C11H10N4SO2)+1–3; (C11H10N3SCl)+4–6 and (C11H10N3SBr)+7–9 ions and the selected fragment ions (EI-MS), as well as (C18H16N5SO4)+1–3; (C18H16N3SCl2)+4–6 and (C18H16N3SBr2) + 7–9 ions and the selected ions (C7H6NO2)+1–3; (C7H6Cl)+ 4–6; (C7H6Br)+ 7–9 (FAB-MS) are discussed. The data obtained can be used for distinguishing isomers.

Mechanism and structure in chemical ionization mass spectrometry: tricyclic flavanoid compounds

1973 ◽  
Vol 26 (7) ◽  
pp. 1577 ◽  
Author(s):  
JW Clark-Lewis ◽  
CN Harwood ◽  
MJ Lacey ◽  
JS Shannon
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectra ◽  
Chemical Ionization ◽  
Ionization Mass Spectrometry ◽  
Chemical Ionization Mass Spectrometry ◽  
Ionization Mass ◽  
Fragmentation Pathways ◽  
Fragment Ions ◽  
Metastable Ions ◽  
Fragmentation Patterns

The chemical ionization mass spectra of a series of tricyclic flavanoid compounds have been examined using isobutane and hydrogen as reagent gases and the fragmen- tation modes have been correlated systematically in terms of structure. The technique produces simple fragmentation patterns and abundant metastable ions. The use of deuterium as reagent gas reveals the influence of extraneous water on the spectra and facilitates the interpretation of the fragmentation pathways. The fragment ions appear to arise from isomeric progenitors protonated at different sites in the molecules.

Mass Spectrometry of Some Substituted 2-Benzylidenecyclohexanones and 2,6-bis-Benzylidenecyclohexanones

1973 ◽  
Vol 51 (9) ◽  
pp. 1458-1470 ◽  
Author(s):  
P. J. Smith ◽  
J. R. Dimmock ◽  
W. A. Turner
Keyword(s):  
Mass Spectrometry ◽  
Carbon Monoxide ◽  
Substitution Reaction ◽  
Mass Spectra ◽  
Aromatic Substitution ◽  
Fragmentation Pathways ◽  
Ortho Substituent

The mass spectra of a series of some substituted 2-benzylidenecyclohexanones and a series of substituted 2,6-bis-benzylidenecyclohexanones have been determined at 70 eV. The major fragmentation pathways include an intramolecular aromatic substitution reaction leading to the loss of an ortho-substituent with the formation of a stable benzopyrylium ion, loss of carbon monoxide and ethylene from the parent ion and also further ions derived from subsequent cleavages of the cyclohexanone ring. The structural and electronic factors involved in the aromatic substitution reaction were examined by comparing the M – H/M and M – Cl/M ratios determined from the spectra of the various substrates.

Mass Spectrometry of N-Benzoyl-2-hydroxyalkylamines. Role of the Hydroxylic Hydrogen in the Fragmentation Pattern

1975 ◽  
Vol 53 (21) ◽  
pp. 3175-3187 ◽  
Author(s):  
Don C. DeJongh ◽  
Denis C. K. Lin ◽  
Pierre LeClair-Lanteigne ◽  
Denis Gravel
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectra ◽  
Hydroxyl Group ◽  
Fragmentation Pattern ◽  
Relative Importance ◽  
Hydrogen Atoms ◽  
Related Compounds ◽  
Double Hydrogen ◽  
Hydrogen Rearrangement

An interesting rearrangement has been observed in the mass spectra of a series of N-benzoyl-2-hydroxyalkylamines. The hydrogen atom of the hydroxyl group is transferred to the N-benzoyl portion of the molecular ion and the bond between positions 1 and 2 in the N-alkyl group is cleaved. A rearrangement ion, observed at m/e 135, is formed along with a neutral aldehyde or ketone. When the hydroxylic hydrogen is replaced by a trimethylsilyl substituent, the latter group is transferred with comparable efficiency. Differences in the relative importance of this rearrangement in the mass spectra of a series of related compounds with decreasing substitution at position 2, have been explained by differences in the stabilities of the neutral molecules formed along with m/e 135 and by the occurrence of a double hydrogen rearrangement which competes if hydrogen atoms are present in a relationship gamma and delta to the carbonyl group.

374. Pyrroles and related compounds. Part IV. Mass spectrometry in structural and stereochemical problems. Part XXX. Mass spectra of monocyclic derivatives of pyrrole

1964 ◽  
pp. 1949 ◽  
Author(s):  
H. Budzikiewicz ◽  
C. Djerassi ◽  
A. H. Jackson ◽  
G. W. Kenner ◽  
D. J. Newman ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectra ◽  
Derivatives Of ◽  
Related Compounds

Fragmentation pathways in the mass spectra of isomeric phenylazoxypyridine-N-oxides

1992 ◽  
Vol 70 (4) ◽  
pp. 1028-1032 ◽  
Author(s):  
Nigel J. Bunce ◽  
H. Stewart McKinnon ◽  
Randy J. Schnurr ◽  
Sam R. Keum ◽  
Erwin Buncel
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Electron Impact ◽  
Mass Spectra ◽  
Chemical Reduction ◽  
Ion Source ◽  
Tandem Mass ◽  
Mass Spectral Fragmentation ◽  
Fragmentation Pathways ◽  
Mass Spectral

The mass spectral fragmentation pathways of a series of phenylazoxypyridine-N-oxides have been studied under electron impact conditions using tandem mass spectrometry. Besides simple C—N cleavages, the azoxypyridine-N-oxides undergo deep-seated rearrangements directly from the molecular ion. In addition, the spectra are complicated by a purely chemical reduction of the N—O functionalities that occurs in the ion source prior to ionization.

Naphtho[1,8-bc]thiophens. II. Mass spectrometry

1968 ◽  
Vol 21 (1) ◽  
pp. 171 ◽  
Author(s):  
DG Hawthone ◽  
QN Porter
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectra ◽  
Electron System ◽  
Complete Analysis ◽  
Base Peak ◽  
Aromatic System ◽  
Chemical Research ◽  
Fragment Ions ◽  
The Stability ◽  
Derivatives Of

II.* MASS SPECTROMETRY By D. G. HAWTHORN,E~$ and Q. N. PORTER^ [Manzlscript received March 6, 19671 The high-resolution mass spectra of some derivatives of naphtho[l,S-be]- thiophen have been analysed. The base peak in the spectra is usually the naphtho- [1,8-bclthienylium cation (mle 171) or one of its substitution products; this emphasizes the stability of this species. Structures are suggested for most of the other ions observed in the spectra. INTRODUUTION In Part I, which dealt with the synthesis of naphtho[l,8-bclthiophen derivatives, the mass spectra of the 2-methyl-2H- (I; R = CH,) and 2-phenyl-2H- (I; R = Ph) compounds were briefly described. It was suggested that in each case the cleavage shown gave the ion of mle 171, for which the naphthothienylium cation structure ac was proposed. (1) ac; m/e 171 In this paper we present a complete analysis of the spectra of these compounds, and of some related naphtho[l,8-bclthiophen derivatives. For reasons outlined in Part I of this series, it is not possible to write structures for fragment ions from aromatic and heteroaromatic molecules with the confidence with which this can be done for many less-aromatic systems. In writing ionic structures to formalize the observed spectra, the following principles have been used: (i) Where the formation of an odd-electron system is involved, the ion is, if possible, written as a radical cation derivable from an aromatic system. There is * Part I, Aust. J. Chem., 1966, 19, 1909. t Department of Organic Chemistry, University of Melbourne, Vic. 3052. $ Present Address: Division of Applied Mineralogy, CSIRO Chemical Research Labora- tories, Melbourne, Vic. 3001. Aust. J. Chem., 1968, 21, 171-83

Liquid Secondary Ion Mass Spectrometry and Collision-induced Dissociation Mass Spectrometry of Sulfonamide Derivatives of meso-Tetraphenylporphyrin

1999 ◽  
Vol 03 (03) ◽  
pp. 172-179 ◽  
Author(s):  
M. ROSÁRIO M. DOMINGUES ◽  
M. GRAÇA SANTANA-MARQUES ◽  
A. J. FERRRER-CORREIA ◽  
AUGUSTO C. TOMÉ ◽  
MARIA G. P. M. S. NEVES ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectra ◽  
Secondary Ion Mass Spectrometry ◽  
Molecular Ions ◽  
Collision Induced Dissociation ◽  
Fragment Ions ◽  
Ion Mass Spectrometry ◽  
Derivatives Of ◽  
Secondary Ion

Liquid secondary ion mass spectrometry (LSIMS) and collision-induced dissociation (CID) were used for the characterization of sulfonamide derivatives of meso-tetraphenylporphyrin (TPP). The spectra obtained using LSIMS show abundant molecular ions and fragment ions from losses of the sulfonamide moieties. The main fragmentation observed in the LSI mass spectra and in the CID spectra of the protonated or cationized molecules involves the loss of one sulfonamide group. In addition, in the CID spectra of these compounds the fragment ions formed by the elimination of two, three and/or four sulfonamide groups are also observed. The CID spectra of the protonated or cationized molecules of these derivatives do not display the ions formed by the cleavage of the S - N bond which have been reported for other sulfonamide compounds. The LSI mass spectra and CID spectra of sulfonamide derivatives of meso-tetraphenylporphyrin provide an easy and reliable means of identification of the number and nature of sulfonamide groups in the porphyrinic ring.

Analysis of Testosterone Esters by Tandem Mass Spectrometry

1993 ◽  
Vol 76 (2) ◽  
pp. 306-312 ◽  
Author(s):  
Thomas Cairns ◽  
Emil G Siegmund ◽  
Bobby Rader
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Relative Abundance ◽  
Mass Spectra ◽  
Chemical Ionization ◽  
Generic Product ◽  
Tandem Mass ◽  
Fragment Ions ◽  
Product Ions ◽  
The Individual

Abstract The electron ionization (El) and chemical ionization (CI) mass spectra of 12 representative testosterone esters were examined to explore the various analytical options available for identification and confirmation of the esters. Using El, a number of fragment ions indicated the identification of the testosterone moiety, but structural confirmation of the individual esters often required the observance of the molecular ion at very low relative abundance ratios. The acceptable analytical method involved CI/tandem mass spectrometry based on the production of the 2 generic product ions derived from the protonated molecule ion.

Study of the Fragmentation Pathways of Sulfonamides by High-resolution Mass Spectrometry: Application to their Detection in Plasma by Direct Infusion

2020 ◽  
Vol 16 (5) ◽  
pp. 513-519
Author(s):  
Maroula G. Kokotou
Keyword(s):  
Mass Spectrometry ◽  
High Resolution ◽  
High Resolution Mass Spectrometry ◽  
Structural Features ◽  
Direct Infusion ◽  
Sulfonamide Antibiotics ◽  
Fragmentation Pathways ◽  
Fragment Ions ◽  
High Resolution Mass ◽  
Resolution Mass

Background: The high resolving and accuracy power of the HRMS instrument enabled us to identify the product ions and to propose detailed fragmentation pathways and diagnostic fragment ions. Methods: In the present work, the fragmentation pathways of five sulfonamides antibiotics, namely sulfamerazine, sulfathiazole, sulfadiazine, sulfadimethoxine and sulfamethoxazole, by High-Resolution Mass Spectrometry (HRMS) are presented. The HRMS spectra were recorded with a Q-TOF (Time of Flight) spectrometer with Electrospray Ionization (ESI) in both negative and positive mode. Results: Specific characteristic ions for each one of the sulfonamide antibiotics under positive ESI mode are proposed for the first time. Fragment ions of this particular class of analytes may be used to rapidly identify compounds with common structural features. Conclusion: The direct infusion of plasma samples, avoiding any prior chromatographic steps, to identify the existence of sulfonamide antibiotics is demonstrated herein.

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