Free radicals by mass spectrometry. XXXVIII. Primary steps in the mercury-photosensitized decompositions of dimethyl sulfide and dimethyldisulfide

1968 ◽  
Vol 46 (6) ◽  
pp. 833-839 ◽  
Author(s):  
A. Jones ◽  
S. Yamashita ◽  
F. P. Lossing
Keyword(s):  
Mass Spectrometry ◽  
Free Radicals ◽  
Dimethyl Sulfide ◽  
Primary Decomposition

The reaction between mercury (3P1) atoms and dimethylsulfide at 55 °C has been shown to be exclusively[Formula: see text]Two primary modes of dissociation have been established for the corresponding reaction with dimethyldisulfide.[Formula: see text]The former reaction accounts for ~20% of the primary decomposition at 55 °C. No reaction leading to H-atom removal was found for either compound.The subsequent reactions of CH3S and CH3SS radicals, chiefly combination and disproportionation, have been investigated briefly.

FREE RADICALS BY MASS SPECTROMETRY: XXII. PRIMARY DECOMPOSITION STEPS IN THE MERCURY-PHOTOSENSITIZED DECOMPOSITION OF METHANOL AND DIMETHYL ETHER

1961 ◽  
Vol 39 (1) ◽  
pp. 102-109 ◽  
Author(s):  
R. F. Pottie ◽  
A. G. Harrison, ◽  
F. P. Lossing
Keyword(s):  
Mass Spectrometry ◽  
Free Radicals ◽  
Dimethyl Ether ◽  
Excited Molecule ◽  
Primary Decomposition ◽  
Oh Radicals ◽  
No Formation ◽  
Abstraction Reaction ◽  
Reaction Proceeds ◽  
Low Pressures

The Hg 3P1 photosensitized decomposition of methanol at low pressures proceeds mainly by a dissociation into CH3O radicals and H atoms. No formation of CH2OH radicals is observed. A subsidiary reaction to form CH3 and OH may also be a primary step. Formation of CH2OH radicals at higher pressures is attributed to an abstraction reaction of CH3O with CH3OH.Two primary modes of dissociation are found to occur for dimethyl ether:[Formula: see text]The relative probabilities of occurrence at low pressures are ∼45% and ∼50%, respectively. The possibility that the second reaction proceeds by formation of an excited molecule is discussed.

Free radicals by mass spectrometry. XL. Primary processes and transient intermediates in the mercury (3P1) photosensitization of hydrazine

1969 ◽  
Vol 47 (8) ◽  
pp. 1391-1393 ◽  
Author(s):  
A. Jones ◽  
F. P. Lossing
Keyword(s):  
Mass Spectrometry ◽  
Free Radicals ◽  
Mass Spectrometer ◽  
Direct Evidence ◽  
Flow Reactor ◽  
Low Pressure ◽  
Primary Decomposition ◽  
Fast Flow ◽  
Transient Intermediates ◽  
Fast Flow Reactor

The low pressure mercury (3P1) photosensitized decomposition of hydrazine has been studied at 55 °C in a fast flow reactor coupled to a mass spectrometer. Direct evidence was obtained for the participation of N2H2, N2H3, NH2, and NH in the decomposition, and two primary decomposition modes were established[Formula: see text]

Heats of formation of free radicals by mass spectrometry

1973 ◽  
Vol 95 (20) ◽  
pp. 6562-6566 ◽  
Author(s):  
D. K. Sen. Sharma ◽  
J. L. Franklin
Keyword(s):  
Mass Spectrometry ◽  
Free Radicals ◽  
Heats Of Formation

FREE RADICALS BY MASS SPECTROMETRY: X. THE IONIZATION POTENTIALS OF METHYL SUBSTITUTED ALLYL RADICALS

1956 ◽  
Vol 34 (3) ◽  
pp. 345-353 ◽  
Author(s):  
C. A. McDowell ◽  
F. P. Lossing ◽  
I. H. S. Henderson ◽  
J. B. Farmer
Keyword(s):  
Mass Spectrometry ◽  
Free Radicals ◽  
Electron Impact ◽  
Heat Of Formation ◽  
Ionization Potentials ◽  
Bond Dissociation Energies ◽  
Allyl Radical ◽  
Dissociation Energies ◽  
Allyl Halides ◽  
Vertical Ionization Potentials

The vertical ionization potentials of the β- and γ-methyl substituted allyl radicals as measured by electron impact are 8.03 ± 0.05 v. and 7.71 ± 0.05 v, respectively. From appearance potential data the following bond dissociation energies can be derived, assuming the dissociation processes to be free from complications:[Formula: see text]With assumptions about the structure of the ions produced by electron impact from the corresponding butenes the dissociation energies of the C4H7—H bonds in these latter compounds can be estimated, and the heats of formation of the corresponding radicals derived, namely:[Formula: see text]From data on the allyl halides we evaluate the heat of formation of the allyl radical to be:[Formula: see text]

Sign in / Sign up

Export Citation Format

Share Document