Mass-independent sulfur isotope effect in the nonthermal formation of S/sub 2/F/sub 10/

Journal Article · Thu Jun 01 04:00:00 EDT 1989 · J. Chem. Phys.; (United States)

OSTI ID:6180697

Bains-Sahota, S K; Thiemens, M H

A non-mass-dependent sulfur isotope effect is present in the rotationally symmetric S/sub 2/F/sub 10/ molecule, produced in an electrical discharge through sulfur tetrafluoride. A similar isotopic fractionation was observed in the product S/sub 2/F/sub 10/ from the electrodissociation of SF/sub 5/Cl, and reaction between fluorine atoms produced by F/sub 2/ photolysis and SF/sub 4/, collectively ruling out the SF/sub 5/ formation process as the source of the mass-independent fractionation. The mass-independent mechanism is shown to occur in the SF/sub 5/+SF/sub 5/..-->..S/sub 2/F/sub 10/ formation step. The secondary dissociation of S/sub 2/F/sub 10/ as a source of the mass-independent fractionation is ruled out by control S/sub 2/F/sub 10/ dissociation experiments which are shown to produce small mass-dependent fractionations. Mass-dependent effects such as sulfur isotopic exchange and secondary dissociation reactions are significant processes for the system under study and have been quantitatively accounted for. The role of symmetry in non-mass-dependent isotope effects is strengthened by the present experiments, and the search and characterization of mass-independent effects is extended to sulfur-containing molecules.

• Research Organization: Department of Chemistry, University of California, San Diego, La Jolla, California 92093
• OSTI ID: 6180697
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 90:11; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400202* -- Isotope Effects
Isotope Exchange
& Isotope Separation
CHEMICAL REACTION KINETICS
CHEMISTRY
DISSOCIATION
ELECTRIC DISCHARGES
ELECTROCHEMISTRY
FLUORIDES
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
ISOTOPE EFFECTS
KINETICS
REACTION KINETICS
SULFUR COMPOUNDS
SULFUR FLUORIDES
SYNTHESIS