Mass spectral studies of lanthanide chelates. II. Lanthanide chelates of three fluorinated β-diketones

1976 ◽  
Vol 29 (8) ◽  
pp. 1845 ◽  
Author(s):  
SE Livingstone ◽  
WA Zimmermann
Keyword(s):  
Mass Spectrometer ◽  
Mass Spectra ◽  
Nitrate Solution ◽  
Alcoholic Solution ◽  
Spectral Studies ◽  
Mass Spectral ◽  
Lanthanide Nitrate ◽  
Aqueous Alcoholic Solution ◽  
Lanthanide Chelates ◽  
Chemical Behaviour

The lanthanide chelates MetL3,nH2O (Met = Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, or Yb; L = PhCO= CHCOCF3, p-MeC6H4CO=CHCOCF3, p-MeOC6H4CO=CHCOCF3; n = 2, 3 or 1) have been isolated. The conditions were found to be critical, involving the slow addition of an ammoniacal aqueous alcoholic solution of the β-diketone to an excess of the lanthanide nitrate solution while the pH was maintained within the range 6.0-6.5. The mass spectra of most of the chelates were obtained and were essentially similar and fluorine migration to the metal was found to occur. Although a peak for the ion M-L (M = MetL3+) is present in the spectra, peaks for M-2L and M-3L are absent; however, peaks were obtained for the ions M-2L+ F and M-3L+2F (Met111F2). A peak for the ion M- L+ F (Met11F) was obtained when Met = Sm, Eu and Yb. The valency change from 3 to 2 occurring in the mass spectrometer in the case of samarium, europium and ytterbium is in accordance with their chemical behaviour in solution.

Mass spectral studies of lanthanide chelates. I. Samarium, europium, gadolinium and terbium chelates of thenoyltrifluoroacetone

1975 ◽  
Vol 28 (7) ◽  
pp. 1513 ◽  
Author(s):  
M Das ◽  
SE Livingstone
Keyword(s):  
Mass Spectra ◽  
The Other ◽  
Spectral Studies ◽  
Mass Spectral ◽  
Lanthanide Chelates ◽  
Other Hand ◽  
Europium Chelates ◽  
Fragmentation Patterns ◽  
Terbium Chelates ◽  
Bivalent State

The mass spectra of the lanthanide chelates of thenoyltrifluoroacetone, viz. Met{CF3COCH=C(O-)-C4H3S}3 (Met = Sm, Eu, Gd, Tb), have been obtained. All four spectra display similar fragmentation patterns. Fluorine migration to the metal with the concomitant loss of :CF2 occurs with all four lanthanide chelates. Peaks were observed for the ions [MetF2]+ (Met = Sm, Gd, Tb) and [MetF]+ (Met = Sm, Eu). The occurrence of [MetF]+ in the spectra of the samarium and europium chelates is in keeping with the tendency of these two lanthanides to be reduced to the bivalent state. On the other hand, oxidation of terbium(III) to terbium(IV) was not observed in the mass spectra.

scholarly journals Single-particle measurements of bouncing particles and in situ collection efficiency from an airborne aerosol mass spectrometer (AMS) with light-scattering detection

2017 ◽  
Vol 10 (10) ◽  
pp. 3801-3820 ◽  
Author(s):  
Jin Liao ◽  
Charles A. Brock ◽  
Daniel M. Murphy ◽  
Donna T. Sueper ◽  
André Welti ◽  
...  
Keyword(s):  
Light Scattering ◽  
Mass Spectrometer ◽  
Single Particle ◽  
Total Mass ◽  
Mass Spectra ◽  
Collection Efficiency ◽  
Aerosol Mass Spectrometer ◽  
Mass Spectral ◽  
Aerosol Mass ◽  
Spectral Signal

Abstract. A light-scattering module was coupled to an airborne, compact time-of-flight aerosol mass spectrometer (LS-AMS) to investigate collection efficiency (CE) while obtaining nonrefractory aerosol chemical composition measurements during the Southeast Nexus (SENEX) campaign. In this instrument, particles scatter light from an internal laser beam and trigger saving individual particle mass spectra. Nearly all of the single-particle data with mass spectra that were triggered by scattered light signals were from particles larger than ∼ 280 nm in vacuum aerodynamic diameter. Over 33 000 particles are characterized as either prompt (27 %), delayed (15 %), or null (58 %), according to the time and intensity of their total mass spectral signals. The particle mass from single-particle spectra is proportional to that derived from the light-scattering diameter (dva-LS) but not to that from the particle time-of-flight (PToF) diameter (dva-MS) from the time of the maximum mass spectral signal. The total mass spectral signal from delayed particles was about 80 % of that from prompt ones for the same dva-LS. Both field and laboratory data indicate that the relative intensities of various ions in the prompt spectra show more fragmentation compared to the delayed spectra. The particles with a delayed mass spectral signal likely bounced off the vaporizer and vaporized later on another surface within the confines of the ionization source. Because delayed particles are detected by the mass spectrometer later than expected from their dva-LS size, they can affect the interpretation of particle size (PToF) mass distributions, especially at larger sizes. The CE, measured by the average number or mass fractions of particles optically detected that had measurable mass spectra, varied significantly (0.2–0.9) in different air masses. The measured CE agreed well with a previous parameterization when CE > 0.5 for acidic particles but was sometimes lower than the minimum parameterized CE of 0.5.

Infrared, N.M.R. and mass spectral studies on 3-Amino-4-aryl-5-aryl(or alkyl)imino-4,5-dihydro-1,2,4-thiadiazoles

1975 ◽  
Vol 28 (3) ◽  
pp. 591 ◽  
Author(s):  
CP Joshua ◽  
KN Rajasekharan
Keyword(s):  
Spectral Data ◽  
Structure Elucidation ◽  
Mass Spectra ◽  
Spectral Studies ◽  
Mass Spectral ◽  
Fragmentation Patterns ◽  
Chemical Evidence

Some 3-amino-4-aryl-5-aryl(or alkyl)imino-4,5-dihydro-1,2,4-thiadiazol, previously prepared and assigned structures on chemical evidence, are now confirmed in structure by a detailed study of their spectra. While i.r, and n.m.r, spectral data confirm the nature of the ring present in these compounds, mass spectra confirm the assignment of substituents on the ring. Mass spectra of these compounds exhibit specific fragmentation patterns and consequently are useful in structure elucidation of substituted 4,5-dihydro-1,2,4-thiadiazoles.

Synthesis of phenethanolamine derivatives with potential β-adrenergic antagonistic activity

1975 ◽  
Vol 28 (5) ◽  
pp. 1023 ◽  
Author(s):  
SJ Pasaribu ◽  
LR Williams
Keyword(s):  
Magnetic Resonance ◽  
Ring Opening ◽  
Proton Magnetic Resonance ◽  
Mass Spectra ◽  
Antagonistic Activity ◽  
Spectral Studies ◽  
Aryl Ring ◽  
Mass Spectral

The mass spectra of bromonitroacetophenones, intermediates in the synthesis of phenethanolamine derivatives containing a nitro and bromo group in the aryl ring, have been studied. The acetophenones were converted into the corresponding α,β-epoxystyrenes, which were then treated with various amines, and proton magnetic resonance and mass spectral studies were used to confirm the direction of ring opening and purity of the products.

scholarly journals Mass Spectral Studies on Some Naturally Occurring Phloroglucinol Derivatives. III. The Mass Spectra of Some Mono- and Bicyclic Phloroglucinol Derivatives from Rhizomes of Different Dryopteris Species.

1972 ◽  
Vol 26 ◽  
pp. 89-101 ◽  
Author(s):  
Mauri Lounasmaa ◽  
Arto Karjalainen ◽  
Carl-Johan Widén ◽  
Aarre Huhtikangas ◽  
W. B. Pearson ◽  
...  
Keyword(s):  
Mass Spectra ◽  
Spectral Studies ◽  
Mass Spectral ◽  
Naturally Occurring ◽  
Phloroglucinol Derivatives

scholarly journals Mass Spectral Studies on Some Naturally Occurring Phloroglucinol Derivatives. Part I. The Mass Spectra of Filicinic Acid and its Acetyl, Propionyl, and Butyryl Derivatives.

1971 ◽  
Vol 25 ◽  
pp. 3428-3440 ◽  
Author(s):  
Mauri Lounasmaa ◽  
Arto Karjalainen ◽  
Carl-Johan Widén ◽  
Aarre Huhtikangas ◽  
J. Koskikallio ◽  
...  
Keyword(s):  
Mass Spectra ◽  
Spectral Studies ◽  
Mass Spectral ◽  
Naturally Occurring ◽  
Phloroglucinol Derivatives

Mass spectral studies of aromatic aza analogues of juvabione

1986 ◽  
Vol 51 (12) ◽  
pp. 2879-2883
Author(s):  
R. K. Mahajan ◽  
Neelam Gupta ◽  
Satinder K. Uppal
Keyword(s):  
Mass Spectra ◽  
Spectral Studies ◽  
Fragmentation Pattern ◽  
Mass Spectral ◽  
Secondary Amides

Mass spectra of title compounds I-VI have been studied with a view to comparing the fragmentation pattern of secondary amides in different structural environments.

Mass spectral studies of some desaurins and related 3,5-bismethylene-1,2,4-trithiolanes

1968 ◽  
Vol 46 (3) ◽  
pp. 365-375 ◽  
Author(s):  
Peter Yates ◽  
Thomas R. Lynch ◽  
L. S. Weiler
Keyword(s):  
Carbonyl Group ◽  
Mass Spectra ◽  
Molecular Ions ◽  
Spectral Studies ◽  
Mass Measurements ◽  
Metastable Peak ◽  
Fragmentation Pathways ◽  
Mass Spectral ◽  
Accurate Mass Measurements ◽  
Doubly Charged

The mass spectra of three desaurins and four related 3,5-bismethylene-1,2,4-trithiolanes have been interpreted with the aid of metastable peak assignments and accurate mass measurements. Strong molecular ion peaks are observed in the case of the aryl desaurins but not in that of their trithiolane counterparts. A variety of fragmentation pathways are postulated for the molecular ions, including cleavage on either side of a carbonyl group and elimination of a molecule of acylthioketene. In the case of the desaurins the latter process results in the formation of acylthioketene molecular ions, which could be distinguished from the doubly charged desaurin molecular ions. In the case of two of the trithiolanes, it is proposed that the ions resulting from loss of acylthioketene from the molecular ions undergo a novel type of McLafferty rearrangement and loss of carbon suboxysulfide to give aryl mercaptan molecular ions.

scholarly journals Single particle measurements of bouncing particles and in-situ collection efficiency from an airborne aerosol mass spectrometer (AMS) with light scattering detection

2017 ◽  
Author(s):  
Jin Liao ◽  
Charles A. Brock ◽  
Daniel M. Murphy ◽  
Donna T. Sueper ◽  
André Welti ◽  
...  
Keyword(s):  
Light Scattering ◽  
Chemical Composition ◽  
Mass Spectrometer ◽  
Mass Spectra ◽  
Collection Efficiency ◽  
Particle Mass ◽  
Aerodynamic Diameter ◽  
Aerosol Mass Spectrometer ◽  
Mass Spectral ◽  
Aerosol Mass

Abstract. A light scattering module was coupled to an airborne, compact time-of-flight aerosol mass spectrometer (LS-ToF-AMS) to investigate collection efficiency (CE) while obtaining non-refractory aerosol chemical composition measurements during the Southeast Nexus (SENEX) campaign. In this instrument, particles typically larger than ~ 250 nm in vacuum aerodynamic diameter scatter light from an internal laser beam and trigger saving individual particle mass spectra. Over 33,000 particles are characterized as either prompt (27 %), delayed (15 %), or null (58 %), according to the appearance time and intensity of their mass spectral signals. The individual particle mass from the spectra is proportional to the mass derived from the vacuum aerodynamic diameter determined by the light scattering signals (dva-LS) rather than the traditional particle time-of-flight (PToF) size (dva). The delayed particles capture about 80 % of the total chemical mass compared to prompt ones. Both field and laboratory data indicate that the relative intensities of various ions in the prompt spectra show more fragmentation compared to the delayed spectra. The particles with a delayed mass spectral signal likely bounced on the vaporizer and vaporized later on a lower temperature surface within the confines of the ionization source. Because delayed particles are detected at a later time by the mass spectrometer than expected, they can affect the interpretation of PToF mass distributions especially at the larger sizes. CE, measured by the average number or mass fractions of particles optically detected that have measureable mass spectra, varied significantly (0.2–0.9) in different air masses. Relatively higher null fractions and corresponding lower CE for this study may have been related to the lower sensitivity of the AMS during SENEX. The measured CE generally agreed with the CE parameterization based on ambient chemical composition, including for acidic particles that had a higher CE as expected from previous studies.

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