Kinetic energy release in metastable transitions determined by electric sector variation

Reichert, C.; Fraas, Robert E.; Kiser, Robert W.

doi:10.1016/0020-7381(70)85010-0

Cited by 14 publications

(4 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Since the major structural differences for lg and lh versus li are the boron substituents, the observed splitting of the resonance signals is likely to be due to steric factors resulting in conformational isomers. It is worth noting that similar observations have been made for the 13 C NMR spectra of bis(methylamino)-phenylborane and N-trimethyl-B-triphenylborazine [9]. The chemical shift values of the carbon atoms of the ethyl groups bonded to boron do not appear to exhibit a characteristic trend.…”

Section: Nuclear Magnetic Resonance Spectrasupporting

confidence: 52%

“…Substitution of C 1 by methyl groups provokes a downfield shift of (3(C X ) of about 10 ppm (lg, lh and li). Surprisingly, two resonance signals 13 C resonance signals each are observed for both C 1 and C 3 in the spectra of 1 g and 1 i whereas only one each is observed in the spectrum of lh. Since the major structural differences for lg and lh versus li are the boron substituents, the observed splitting of the resonance signals is likely to be due to steric factors resulting in conformational isomers.…”

Section: Nuclear Magnetic Resonance Spectramentioning

confidence: 96%

“…Mass spectral data were obtained with a double-focusing Hitachi-Perkin-Elmer RMU-7 instrument at an electron beam energy of 70 eV. Metastable transitions were studied using the electric sector voltage variation method [12,13]. Ultraviolet spectra were obtained on solutions of the compounds in hexane on a Cary Model 15 spectrophotometer.…”

Section: Methodsmentioning

confidence: 99%

“…Very few 13 C NMR data on organoboranes are known and it is yet difficult to establish general trends [6], although some correlations of chemical shift data have been discussed [7,8]. Carbon-13 NMR data for selected pyrazaboles are compiled in Table I, From these data it is apparent that changing R = R' in 1 from H to C2H5 (1 a and 1 j) has virtually no effect on the chemical shift values of C 1 and C 2 as compared to the corresponding values for pyrazole.…”

Section: Nuclear Magnetic Resonance Spectramentioning

confidence: 99%

See 3 more Smart Citations

Spectroscopic Studies on Pyrazaboles

May¹,

Niedenzu²,

Trofimenko³

1978

Zeitschrift Für Naturforschung B

View full text Add to dashboard Cite

The mass spectra of several pyrazaboles of type 1 where R and/or R′ = C2H5 have been studied. The loss of boron-bonded hydrocarbon moieties under electron impact is the predominant feature of all spectra. Some ultraviolet and nuclear magnetic resonance data on compounds of type 1 have been collected; bulky substituents were observed to lead to conformational isomers that can be detected by 13C NMR spectroscopy

show abstract

Section: Nuclear Magnetic Resonance Spectrasupporting

confidence: 52%

Section: Nuclear Magnetic Resonance Spectramentioning

confidence: 96%

Section: Methodsmentioning

confidence: 99%

Section: Nuclear Magnetic Resonance Spectramentioning

confidence: 99%

See 2 more Smart Citations

Spectroscopic Studies on Pyrazaboles

May¹,

Niedenzu²,

Trofimenko³

1978

Zeitschrift Für Naturforschung B

View full text Add to dashboard Cite

show abstract

Fragmentation de Triazoles Sous L'Impact Electronique—II 1,2,3‐Triazole

Maquestiau

Haverbeke

Flammang

et al. 1973

Org. Mass Spectrom.

View full text Add to dashboard Cite

Abstract-l,2,4-and 1,2,3-triazoles behave similarly upon electron-impact ; this is ascribed to the formation of common ionic structures. Metastable transitions observed for the loss of nitrogen are studied and interpreted in terms of: (i) the existence of the two tautomers of 1,2,3-triazole in the gaseous phase and (ii) the isomerisation of the molecular ion before fragmentation.RBsumB-La similitude de comportement des 1,2,4-et 1,2,34riazoles sous l'impact Clectronique a t attribuke i la formation de structures ioniques communes. L'ttude des transitions mitastables correspondant B la perte d'une molkcule d'azote semble indiquer que, dans le cas du 1,2,3-triazole, les deux formes tautomkres coexistent i I'ttat gazeux et qu'une isomkrisation partielle de I'ion molkculaire se produit avant dbgradation.

show abstract

A novel mass marker for metastable ion scans in a double focusing mass spectrometer

Porter¹,

Brenton²,

Beynon³

et al. 1980

Org. Mass Spectrom.

View full text Add to dashboard Cite

Characterization and assignment of the products of metastable decompositions which are transmitted by a double focusing mass spectrometer, is often complicated by the inabiiity to measure precisely the parent/daughter ion mass values directly from the spectra which appear on chart paper. This is often because there are considerably fewer peaks in these types of spectra compared with a normal m a s speetnim obtnined from high energy reactions in the ion source. Electronic cucnits are descnbed which permit accurate parent/daughter ion mass vaiues to be obtained when the products of metastable decompositions are transmitted through the ZAB-2F double focusing mass spectrometer. Digital logic circuitry is also described which is used to mark mass vaiues during a sean by driving either a solenoid pen drive unit for a charí recorder or a galvanometer on a muiti-range ultraviolet osciüograph recorder.

show abstract

Kinetic energy release in metastable transitions determined by electric sector variation

Cited by 14 publications

References 13 publications

Spectroscopic Studies on Pyrazaboles

Spectroscopic Studies on Pyrazaboles

Fragmentation de Triazoles Sous L'Impact Electronique—II 1,2,3‐Triazole

A novel mass marker for metastable ion scans in a double focusing mass spectrometer

Contact Info

Product

Resources

About