Gas-liquid chromatography/ultraviolet photoelectron spectroscopy and the photoelectron spectra of nitrosamines

1976 ◽  
Vol 48 (7) ◽  
pp. 1078-1084 ◽  
Author(s):  
D. Betteridge ◽  
Syed K. Hasanuddin ◽  
David I. Rees
Keyword(s):  
Liquid Chromatography ◽  
Photoelectron Spectroscopy ◽  
Photoelectron Spectra ◽  
Ultraviolet Photoelectron Spectroscopy ◽  
Gas Liquid Chromatography

Variable-Temperature Ultraviolet Photoelectron-Spectroscopy of the Keto-Enol Tautomers of Pentane-2,4-Dione

1987 ◽  
Vol 40 (3) ◽  
pp. 599 ◽  
Author(s):  
NS Hush ◽  
MK Livett ◽  
JB Peel ◽  
GD Willett
Keyword(s):  
Photoelectron Spectroscopy ◽  
Energy Region ◽  
Variable Temperature ◽  
Photoelectron Spectra ◽  
Ultraviolet Photoelectron Spectroscopy ◽  
Molecular Orbital Calculations ◽  
Electronic Relaxation ◽  
Relaxation Effects ◽  
Enol Tautomer ◽  
Scf Calculations

The HeI photoelectron spectra of pentane-2,4-dione measured at various temperatures have been subjected to a spectrum-stripping technique to enable isolation of the complete HeI photoelectron spectra of the keto and enol tautomers. The resulting spectrum-stripping coefficients allow evaluation of the enolization equilibrium constant at each temperature and subsequently the enthalpy of enolization. Interpretation of the photoelectron spectra is achieved with the use of ab initio molecular orbital calculations. Photoionization of non-bonding oxygen, and π -type electrons, contribute to the low ionization energy region of the spectrum, with a πCC < no- <πCO ordering for the enol tautpmer , and no- < no+ < πCO+ for the keto tautomer . Because of different electronic relaxation effects, ∆SCF calculations are required to predict correctly the observed πCC/no- spacing for the enol tautomer.

Thermolysis of trimethylsilyl esters: an ultraviolet photoelectron spectroscopy study

1988 ◽  
Vol 66 (6) ◽  
pp. 1430-1439 ◽  
Author(s):  
Nick Henry Werstiuk ◽  
Michael A. Brook ◽  
Peter Hülser
Keyword(s):  
Acetic Acid ◽  
Molecular Orbital ◽  
Photoelectron Spectroscopy ◽  
Small Extent ◽  
Starting Material ◽  
Photoelectron Spectra ◽  
Ultraviolet Photoelectron Spectroscopy ◽  
Spectroscopy Study ◽  
Primary Products ◽  
Trimethylsilyl Trifluoromethanesulfonate

The thermolytic behaviour of trimethylsilyl trifluoromethanesulfonate, 1, trimethylsilyl trifluoroacetate, 2, and trimethylsilyl acetate, 3, has been investigated by ultraviolet photoelectron spectroscopy. Acetate 3 undergoes decomposition only to a small extent at 800 °C via the mechanism shown in Scheme 1 (X = Si); only acetic acid and starting material are detected. In contrast[Formula: see text]with this result, 1 and 2 decompose completely at 725–800 °C and yield products which cannot be derived via the mechanism shown in Scheme 1. Evidence is presented to support our proposal that the thermolysis of 1 yields trimethylsilyl fluoride, 6, and difluorooxathirane dioxide, 7, as primary products. The photoelectron spectra of 1, 2, 3, 6 and trimethylsilanol, 9, are presented. Molecular orbital eigenvalues of dimethylsilene, 4, dimethylsilanone, 5 (calculated using AMPAC and Gaussian 82), 6 and 9 (AMPAC) are reported. Molecular orbital contour diagrams are given for selected MOs of 6 and 9.

The ultraviolet photoelectron spectra of C6F5X compounds, X = (F, Cl, Br, I, H, CH3)

1979 ◽  
Vol 57 (17) ◽  
pp. 2256-2259 ◽  
Author(s):  
Barry C. Trudell ◽  
S. James W. Price
Keyword(s):  
Photoelectron Spectroscopy ◽  
Photoelectron Spectra ◽  
Ultraviolet Photoelectron Spectroscopy

This work provides a study of the 1a2uπ, 2e2gσ, and 1e1gπ levels of a series of C6F5X compounds (X = F, Cl, Br, I, H, CH3) using ultraviolet photoelectron spectroscopy or more simply PES. The three levels are assigned from the PES spectra using the perfluoro effect. A correlation between the energies of these levels and the energies predicted by CNDO/2 and INDO is presented.

A study of lone-pair interactions of tetracyclic diamines by ultraviolet photoelectron spectroscopy

1986 ◽  
Vol 64 (4) ◽  
pp. 760-763 ◽  
Author(s):  
Nick Henry Werstiuk ◽  
Douglas Neve Butler ◽  
Sushil Datta
Keyword(s):  
Photoelectron Spectroscopy ◽  
Lone Pair ◽  
Photoelectron Spectra ◽  
Ultraviolet Photoelectron Spectroscopy ◽  
First Report ◽  
Lone Pairs ◽  
Nitrogen Lone Pair ◽  
Lone Pair Interactions ◽  
Pair Interactions ◽  
Hydrogen Bonded

The ultraviolet photoelectron spectra of 2,7-diazatetracyclo[3.3.3.0.4,90.8,11]undecane (1) and its N,N-dimethyl- and methylene-bridged analogues 2 and 3 are documented. The spectrum of 2, which exhibits a nitrogen lone-pair splitting of 0.95 ± 0.1 eV, is interpreted on the basis of an interaction of "inside" lone pairs of the 1,2-diamine. Apparently this is the first report of a study of such an interaction. The spectrum of 1 is consistent with our view that 1 is an intramolecularly hydrogen bonded species in which the lone pairs are "inside–outside".

A study of asphalt-aggregate interactions using inverse gas-liquid chromatography

1974 ◽  
Vol 24 (11) ◽  
pp. 645-654 ◽  
Author(s):  
F. Alan Barbour ◽  
Richard V. Barbour ◽  
J. Claine Peterson
Keyword(s):  
Liquid Chromatography ◽  
Gas Liquid Chromatography

GASCHROMATOGRAPHIC DETERMINATION OF STEROIDS IN THE URINE OF PATIENTS WITH CUSHING'S SYNDROME

1971 ◽  
Vol 67 (2) ◽  
pp. 303-315 ◽  
Author(s):  
A. J. Moolenaar ◽  
A. P. van Seters
Keyword(s):  
Liquid Chromatography ◽  
Cushing’S Syndrome ◽  
Normal Subjects ◽  
Diagnostic Value ◽  
Cushing's Syndrome ◽  
Gas Liquid Chromatography ◽  
Obese Subjects

ABSTRACT The 17-oxosteroids were estimated in the urine of 27 patients with Cushing's syndrome by gas-liquid chromatography (G. L. C.). The values of the various steroid fractions are compared with those of normal subjects, patients with thyrotoxicosis and obese subjects. The effect of the age of the patients on the diagnostic value of the invidual 17-oxosteroids and their ratios is discussed.

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