OH-Induced Oxidative Cleavage of Dimethyl Disulfide in the Presence of NO

Abstract

We report the results of the theoretical study of (•)OH-induced oxidative cleavage of dimethyl disulfide (DMDS) and the experimental study of the CH3SSCH3 + (•)OH reaction in the presence of (•)NO. Infrared low temperature argon matrix studies combined with ab initio calculations allowed us to identify cis-CH3SONO, which evidences the formation of the CH3SO(•) and CH3SH molecules in the course of the CH3SSCH3 + (•)OH reaction. Ab initio/quantum chemical topology calculations revealed details of the oxidative cleavage of dimethyl disulfide, which is a complex multistep process involving an alteration of S-O and S-S covalent bonds as well as a hydrogen atom transfer. The ability of delocalization of the unpaired electron density by sulfur atoms and a formation of a hydrogen bond by CH3SO(•) and CH3SH are the factors which seem to explain antiradical properties of DMDS.

Reactions of OH and OD radicals with simple thiols and sulfides studied by infrared chemiluminescence of isotopic water products: Reaction OH + CH3SH revisited

“…Our suggestion 3 that the major products of the OH reaction with DMDS are CH 3 SH + CH 3 SO has been confirmed by theoretical studies 20,21 and experimental observations 21 . In our early work, the similarity of the HOD and D 2 O global spectra from the secondary reaction of OD + DMDS and the spectra from CH 3 SD reactions with OD were observed without a detailed examination of the spectra.…”

Two-step reaction mechanism reveals new antioxidant capability of cysteine disulfides against hydroxyl radical attack

“…This difference might lead to the higher %H transfer values for forming + Cys-SH or + I-SH than + Cys-SO • or + I-SO • (SI Appendix, Scheme S2). Hydrogen bond interactions discovered in the cysteinyl disulfide system also presented a distinct difference from the calculated results of • OH reactions with small organic disulfides (20,41).…”

“…Butkovskaya and Setser (19) later detected two product pairs: CH 3 SH/CH 3 SO • and CH 3 S • /CH 3 SOH, with the former pair being found more favorable from reactions of dimethyl disulfide with • OH. Bil et al suggested H atom transfer in the product complex [CH 3 SOH-• SCH 3 ] to be a key step to account for the detection of CH 3 SO • / HSCH 3 (20). However, the product pair CH 3 S • /CH 3 SOH was not detected and thus ruled out in their mechanism.…”

Internal Hydrogen Bond Influences the Formation of [2+2] Schiff Base Macrocycle: Open‐Chain Vs. Hemiaminal and Macrocycle Forms

“…(1) a hemiaminal formation followed by (2) its rearrangement to facilitate the (3) third step, a water elimina-Scheme 1. [50] Particularly suitable for covalently bonded systems, [51][52][53] the electron localization function allows one to partition a molecular space into disjoint basins yielding a chemical interpretation based on concepts of core, bonding, and nonbonding electron pairs, [48,54] which proved to be useful for tracing chemical reactions, [55][56][57][58] also these involving proton and hydrogen transfer processes. [19][20][21][22] tion.…”

“…[44] Quantum chemical topology methods allow the analysis of a bonding situation and a bond evolution in molecules. [50] Particularly suitable for covalently bonded systems, [51][52][53] the electron localization function allows one to partition a molecular space into disjoint basins yielding a chemical interpretation based on concepts of core, bonding, and nonbonding electron pairs, [48,54] which proved to be useful for tracing chemical reactions, [55][56][57][58] also these involving proton and hydrogen transfer processes. [59,60] In particular, quantum chemical topology methods applied to the reaction between benzaldehyde and 4-amine-4H-1,2,4triazole indicated that the nucleophilic addition to form CN covalent bond is preceded by the creation of OH bond, [42,43] contrary to what is typically observed for other systems.…”