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Title: The reaction of alkyl hydropersulfides (RSSH, R = CH 3 and t Bu) with H 2 S in the gas phase and in aqueous solution
The RSSH + H 2 S → RSH + HSSH reaction has been suggested by numerous labs to be important in H 2 S-mediated biological processes. Seven different mechanisms for this reaction (R = CH 3 , as a model) have been studied using the DFT methods (M06-2X and ωB97X-D) with the Dunning aug-cc-pV(T+d)Z basis sets. The reaction of CH 3 SSH with gas phase H 2 S has a very high energy barrier (>45 kcal mol −1 ), consistent with the available experimental observations. A series of substitution reactions R 1 –S–S–H + − S–R 2 (R 1 = Me, t Bu, Ad, R 2 = H, S–Me, S– t Bu, S–Ad) have been studied. The regioselectivity is largely affected by the steric bulkiness of R 1 , but is much less sensitive to R 2 . Thus, when R 1 is Me, all − S–R 2 favorably attack the internal S atom, leading to R 1 –S–S–R 2 . While for R 1 = t Bu, Ad, all − S–R 2 significantly prefer to attack the external S atom to form − S–S–R 2 . These results are in good agreement with the experimental observations.  more » « less
Award ID(s):
1661604
NSF-PAR ID:
10118786
Author(s) / Creator(s):
; ; ; ; ;
Date Published:
Journal Name:
Physical Chemistry Chemical Physics
Volume:
21
Issue:
2
ISSN:
1463-9076
Page Range / eLocation ID:
537 to 545
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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