Determination by mass spectrometry of the structure of bisbenzoylacetoneethylenediimine and its metal chelates

1965 ◽  
Vol 18 (10) ◽  
pp. 1539 ◽  
Author(s):  
SHH Chaston ◽  
SE Livingstone ◽  
TN Lockyer ◽  
JS Shannon
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectrometer ◽  
Mass Spectra ◽  
Metal Chelates ◽  
Methyl Groups ◽  
Rearrangement Reactions

The mass spectra of bisbenzoylacetoneethylenediimine (B) and its cobalt(II), nickel(II), and copper(II) complexes have been rationalized in terms of form (II) for B in which the imino nitrogens are attached to the same carbon atoms as the methyl groups and not to the same carbon atoms as the phenyl groups, as previously proposed in the literature. Compound B is thus NN'-ethylenebis(benzoylisopropylideneimine). Novel ion-rearrangement reactions and examples of changes in metal valency in the mass spectrometer are described.

39 LIPID FINGERPRINTING OF INDIVIDUAL BOVINE BLASTOCYSTS BY DESORPTION IONIZATION ELECTROSPRAY MASS SPECTROMETRY

2012 ◽  
Vol 24 (1) ◽  
pp. 132 ◽  
Author(s):  
C. R. Ferreira ◽  
L. S. Eberlin ◽  
J. E. Hallett ◽  
R. G. Cooks
Keyword(s):  
Mass Spectrometry ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Free Fatty Acids ◽  
Mass Spectrometer ◽  
Lipid Composition ◽  
Mass Spectra ◽  
Ms Analysis ◽  
Desi Ms ◽  
Complex Lipids

Mass spectrometry (MS) allows the detection and structural characterisation of intact molecules such as fatty acids and complex lipids. Desorption electrospray ionization (DESI) is an ambient ionization technique used for MS analysis and profiling and imaging of drugs, metabolites and lipids directly from biological samples with no sample preparation. With the recent introduction of morphologically friendly DESI-MS solvent systems, it is also possible to acquire DESI-MS data non-destructively. Due to the extractive nature of these solvent combinations, enough ion intensity can be generated to chemically profile samples of microscopic dimensions. The objective of this work was to perform chemical profiling on intact bovine blastocysts by DESI-MS, focusing on lipid distributions. Blastocysts produced in vitro were washed 3 times in PBS + 0.1% polyvinyl alcohol to remove lipids present in the culture medium, were placed in PBS/methanol 50% and stored under –20°C for 1 week. For DESI-MS analysis, the embryos were simply placed in glass slides and allowed to dry at room temperature. Mass spectra were acquired in the negative ion mode at the mass/charge range from m/z 150 to 1000, using as solvents a combination of 1:1 (vol/vol) ethanol:dimethylformamide (DMF) or acetonitrile:DMF. The mass spectrometer used was a LTQ linear ion trap mass spectrometer controlled by Xcalibur 2.0 software (Thermo Fisher Scientific, San Jose, CA, USA). The lipid species detected included deprotonated free fatty acids such as palmitic acid (m/z 255.2), stearic acid (m/z 283.2), arachidonic acid (m/z 311.2) and docosanoic acid (m/z 339.3). Free fatty acid dimers appear in the region from m/z 500 to 650 and complex lipids represented mainly by glycerophospholipid classes appear in the region from m/z 700 to 1000 and include phosphatidylinositols (PI 38:1; m/z 788.7), phosphatidylserines (PS 36:1, m/z 885.7) and also the chlorinated phosphatidylcholines (PC 36:1; m/z 794.7). After recording the mass spectra, embryos could still be observed in the glass slide with evident dehydration due to the action of the organic solvent. Since lipid composition of bovine embryos is closely related to cryosensitivity and due to the limited amount of analytes (each embryo is estimated to have a mass of 15 pg of total lipids) lipid analysis usually involves the pooling of individuals to have a large enough amount of analytes. Traditionally, gas chromatography is used for fatty acid residue analysis in oocytes and embryos pooled are submitted to lipid extraction and derivatization. Mass spectrometry by DESI, however, allows direct analysis of intact and single embryos and the profiling of not only free fatty acids but also complex lipids, represented mainly by 3 glycerophospholipid classes (PC, PI and PS). We envisage that DESI-MS will likely become a routine tool for the analysis of lipid composition in mammalian embryos and will contribute significantly to the development of culture systems that produce embryos with higher cryoresistance. Support from the Purdue University Center for Cancer Research Small Grants Program is gratefully acknowledged.

The formation of (CH3)7Si2+ in (CH3)4Si/CH4 mixtures and CH3− exchange reactions between (CH3)4Si, (CH3)4Ge, and (CH3)4Sn studied by high pressure mass spectrometry

1987 ◽  
Vol 65 (12) ◽  
pp. 2849-2854 ◽  
Author(s):  
Anastasia C. M. Wojtyniak ◽  
Xiaoping Li ◽  
John A. Stone
Keyword(s):  
Mass Spectrometry ◽  
High Pressure ◽  
Equilibrium Constant ◽  
Mass Spectrometer ◽  
Excellent Agreement ◽  
Ion Source ◽  
Methyl Groups ◽  
Exchange Reactions ◽  
Equilibrium Reactions ◽  
Association Equilibrium

The association equilibrium [Formula: see text] has been studied in a high pressure mass spectrometer ion source using tetramethylsilane/methane mixtures. Measurement of the equilibrium constant over a range of temperatures yields ΔH0 = −22.3 ± 0.4 kcal mol−1 and ΔS0 = −35.2 ± 0.9 cal mol−1 K−1. Collision-assisted dissociation experiments suggest that the methyl groups retain their integrity in (CH3)7Si2+. Mixed ions such as (CH3)7SiGe+ and (CH3)7GeSn+ were not observed in mixtures of (CH3)4X and (CH3)4Y(X ≠ Y = Si, Ge, Sn). Instead CH3− transfer equilibrium reactions were observed viz. [Formula: see text] (ΔH0 = −10.2 ± 1.2 kcal mol−1, ΔS0 = −3.7 ± 2.4 cal K−1 mol−1) and [Formula: see text], ΔS0 = −0.9 ± 1.6 cal K−1 mol−1. These are in excellent agreement with some published differences in appearance potentials for (CH3)3X+ from (CH3)4X (X = Si, Ge, Sn).

Thio derivatives of β-Diketones and their metal chelates. XV. Mass spectra of cobalt(III) and rhodium(III) chelates of some fluorinated Monothio-β-diketones

1974 ◽  
Vol 27 (6) ◽  
pp. 1177 ◽  
Author(s):  
M Das ◽  
SE Livingstone
Keyword(s):  
Thermal Degradation ◽  
Mass Spectrometer ◽  
Mass Spectra ◽  
Cobalt Complexes ◽  
Metal Chelates ◽  
Complex Ions ◽  
Molecular Ion ◽  
Derivatives Of ◽  
Bivalent State ◽  
Cobalt Chelates

The mass spectra of the cobalt(111) and rhodium(111) chelates of the fluorinated monothio-β-diketones RC(SH)=CHCOCF3 (R = Ph, p-MeC6H4, p-BrC6H4, p-FC6H4, and 2-thienyl) and of the cobalt(111) chelate of CH3C(SH)=CHCOCF3 have been obtained. The cobalt chelates do not give a peak for the molecular ion because of thermal degradation to the cobalt(11) complex CO(RCS=CHCOCF3)2, which then undergoes reactions in the mass spectrometer. Fluorine migration occurs with cobalt but not with rhodium. The cobalt complexes give rise to more metal-containing fragments than their rhodium analogues. Mechanisms are proposed for the reactions involving the metal-containing fragments. Cobalt undergoes valency changes to give cobalt(11) and cobalt(1) complex ions, whereas rhodium undergoes a valency change to the bivalent state only.

Thio derivatives of β-Diketones and their metal chelates. XVII. Mass spectra of iron(III) and ruthenium(III) chelates of some fluorinated Monothio-β-diketones

1974 ◽  
Vol 27 (10) ◽  
pp. 2115 ◽  
Author(s):  
M Das ◽  
SE Livingstone
Keyword(s):  
Thermal Degradation ◽  
Mass Spectrometer ◽  
Mass Spectra ◽  
Metal Chelates ◽  
Iron Chelates ◽  
Molecular Ion ◽  
Derivatives Of

The mass spectra of the iron(111) and rhodium(111) chelates of the fluorinated monothio-β-diketones RC(SH)=CHCOCF3 (R = Ph,p-MeC6H4, 2-thienyl) have been obtained. Whereas the ruthenium(111) chelates give a peak for the molecular ion, the iron(111) chelates do not, due to thermal degradation to the iron(11) complex Fe(RCS=CHCOCF3)2 which then undergoes reactions in the mass spectrometer. Fluorine migration occurs with two of the iron chelates but not with the ruthenium chelates. Mechanisms are proposed for the reactions of the ruthenium chelates.

Thermal decomposition ractions of caledonite and their products

1986 ◽  
Vol 50 (357) ◽  
pp. 521-526 ◽  
Author(s):  
D. J. Morgan ◽  
S. St. J. Warne ◽  
S. B. Warrington ◽  
P. H. A. Nancarrow
Keyword(s):  
Mass Spectrometry ◽  
Phase Transition ◽  
Thermal Analysis ◽  
Thermal Decomposition ◽  
Differential Thermal Analysis ◽  
Mass Spectrometer ◽  
Mass Spectra ◽  
Decomposition Products ◽  
Lead Sulphate ◽  
Ion Fragmentation

AbstractThe thermal decomposition of caledonite has been examined by simultaneous differential thermal analysis, thermogravimetry and mass spectrometry. Structural H2O and CO2 are liberated endothermically between 300 and 400°C leaving a residue of lead sulphate, oxysulphate, and Cu(I) and Cu(II) oxides. A series of sharp endothermic peaks between 850 and 950°C correspond to phase transition and melting reactions of the PbO-PbSO4 mixture. The sulphate anion breaks down above 880 °C. Mass spectra of the gaseous decomposition products show SO2, SO, and O2, although SO is an artefact arising from ion fragmentation of the SO2 within the mass spectrometer. The residue at 1060 °C is composed predominantly of 2PbO · PbSO4 and Cu(I) and Cu(II) oxides.

Studies in Mass Spectrometry. I. Structures and Reactions of Ions from Benzyl Alcohol, ortho-, meta-, and para-Hydroxybenzyl Alcohols, and their 0-Deuterated Derivatives

1962 ◽  
Vol 15 (2) ◽  
pp. 265 ◽  
Author(s):  
JS Shannon
Keyword(s):  
Mass Spectrometry ◽  
Benzyl Alcohol ◽  
Mass Spectra ◽  
Molecular Ions ◽  
Complex Structures ◽  
Π Complex ◽  
Rearrangement Reactions ◽  
Hydroxybenzyl Alcohol

The work described in the present paper, which was undertaken in the course of investigations into the mass spectra of coal and coal fractions, led the author to propose mechanisms of dissociation and rearrangement reactions of ions derived from benzyl alcohol and from o-, m-, and p-hydroxybenzyl alcohol on the basis of a study of; (i) the mass spectra of these latter compounds, including comparable features in the mass spectra of 1,4-cyclohexadiene and O-deuterated o- and p-cresols; (ii) the mass spectra of the corresponding 0-deuterated benzyl and hydroxybenzyl alcohols; (iii) meta-stable transitions. π-Complex structures may play an important role in the dissociation of some of the ions-for example, in the loss of D2O from molecular ions of m- and p-hydroxybenzyl alcohols.

Identification of Rubber Polymers by Mass Spectrometry

1963 ◽  
Vol 36 (3) ◽  
pp. 794-798
Author(s):  
J. K. Phillips
Keyword(s):  
Mass Spectrometry ◽  
High Temperature ◽  
Mass Spectrometer ◽  
Mass Spectra ◽  
Analytical Procedure ◽  
Rubber Compound ◽  
Quantitative Analyses ◽  
The Common ◽  
Textile Polymers ◽  
Qualitative Analyses

Abstract The identity of an elastomer or elastomers in a rubber compound can be determined within a few minutes by the use of a new analytical procedure described in this article. It involves high temperature pyrolysis for two seconds, in vacuo, with an arc imaging furnace and subsequent analysis of the gaseous pyrolyzate with a mass spectrometer. Numerical values derived from the mass spectra of standards permit semi-quantitative analyses of some mixtures of elastomers in cured products. Qualitative analyses have also been made on most of the common textile polymers and a small number of miscellaneous polymers.

Thio derivatives of β-diketones and their metal chelates. XVIII. Mass spectra of some metal chelates of the monothio derivatives of benzoylacetone anddibenzoylmethane

1975 ◽  
Vol 28 (3) ◽  
pp. 513 ◽  
Author(s):  
M Das ◽  
SE Livingstone
Keyword(s):  
Thermal Degradation ◽  
Mass Spectrometer ◽  
Mass Spectra ◽  
Zinc Complex ◽  
Free Ligand ◽  
Cobalt Complexes ◽  
Metal Chelates ◽  
Bivalent Metal ◽  
Free Ions ◽  
Derivatives Of

The mass spectra of the iron(III), cobalt(III), nickel(II) and zinc(II) complexes of the monothio-β-diketones RC(SH)=CHCOPh (R = Me, Ph) have been obtained. The iron and cobalt complexes of 3-mercapto-1-phenylbut- 2-en-1-one (R = Me) do not give a peak for the molecular ion due to thermal degradation to the bivalent metal complex Met(MeCS=CHCOPh)2 (Met = Fe, Co), which then undergoes reactions similar to those undergone by the nickel and zinc complexes. The most interesting feature of the spectra is the loss of hydrogen sulphide which does not occur with the free ligand or with metal complexes of fluorinated monothio-8-diketones RC(SH)=CHCOCF3. ��� The zinc complex of 3-mercapto-1,3-diphenylprop-2-en-1-one (R = Ph) undergoes fragmentation in the mass spectrometer to produce inter alia [ZnC6H5]+. However, the iron(III), cobalt(III), nickel(II) and palladium(II) complexes undergo thermal degradation in the mass spectrometer but the mass spectra of these four complexes give metal-free ions with m/e greater than m/e for L, due to fragmentation of the ion 2L.

The Ion Kinetic Energy Spectra of Benzyl Fluoride and the Isomeric Fluorotoluenes

1974 ◽  
Vol 52 (6) ◽  
pp. 867-869 ◽  
Author(s):  
S. Safe ◽  
W. D. Jamieson ◽  
D. J. Embree
Keyword(s):  
Mass Spectrometry ◽  
Kinetic Energy ◽  
Mass Spectrometer ◽  
Aromatic Compounds ◽  
Mass Spectra ◽  
Energy Spectra ◽  
Model Compounds ◽  
Free Region ◽  
Field Free Region ◽  
Ion Kinetic Energy

One of the classical problems in mass spectrometry is the structure and formation of the C7H7+ and XC7H6+ ions which are generated in the mass spectra of alkylbenzenes and many other aromatic compounds. The intermediacy of both symmetrical tropylium ion structures and unsymmetrical benzyl ions has been postulated using a number of different approaches. We have investigated this problem using ion kinetic energy spectroscopy, a relatively new technique, with the isomeric fluorobenzenes and benzyl fluoride as model compounds. Our results indicated incomplete substituent (i.e. fluorine) scrambling in the first field-free region of the mass spectrometer and thus incomplete equilibration in the decomposing FC7H6+ ions and these conclusions are in contrast to results obtained using other techniques.

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