UV-vis and IR spectroscopic characterization of diphenyl disulfide radical cation in acid zeolites and its rearrangement to thianthrenium radical cation

Diaryldichalcogenide radical cations

“… 8 The one-electron oxidation of (PhS) 2 ( 1a ) and its Se-congener (PhSe) 2 ( 1b ) in the confined voids of the acidic pentasil zeolithe allowed the tentative characterization of the radical cations [(PhS) 2 ]˙ + ( 2a ) and [(PhSe) 2 ]˙ + ( 2b ) by EPR spectroscopy. 9 Previous attempts to prepare a persistent dialkyldisulfide radical cation using (NeoS) 2 ( 7 ; Neo = neopentyl) and nitrosyl triflate [NO][O 3 SCF 3 ] afforded a dialkyldisulfide nitrosonium adduct [(NeoS) 2 ·NO] + ( 8 ) comprising a four-membered ring structure ( Scheme 2 ). 10 The related diamagnetic dicationic rings [(MeSe) 4 ] 2+ ( 9 ) and [(EtTe) 4 ] 2+ ( 10 ) were similarly obtained by the one-electron oxidation of heavier group 16 dialkyldichalcogenides (MeSe) 2 ( 11 ) and (EtTe) 2 ( 12 ) with [NO][O 3 SCF 3 ].…”

Dual Behavior of ZSM-5 as Brønsted Acid and Electron Acceptor in the Adsorption ofN,N′-Diphenylhydrazine

“…There is ample evidence that acid sites in HZSM-5 can function as single electron acceptors; [9Ϫ11,19,26Ϫ28] dehydrogenation in zeolites likewise has precedent. [9,11,19,28] At the low loading levels typical for these experiments, the transfer of the electron, proton, or the hydrogen atom to the ZSM-5 matrix does not cause any noticeable changes in the zeolite. The electron will deactivate the Lewis sites by reducing the nonframework aluminate clusters, Al n (OH) x O y…”

“…The mechanism proposed here, competing mechanisms with two different primary intermediates generated at two types of active sites, readily account for all observed features. In media other than zeolites, there is ample precedent for the quantitative oxidation of DPH to AB using various mild oxidizing agents, including atmospheric oxygen; [28] the converse reductive NϪN cleavage is less common.…”

Oxidation of Aryl- and Diarylcyclopropanes in a Pentasil Zeolite: Ring Opening with Deprotonation or Net Hydrogen Migration

“…In view of the demonstrated redox reactivity of Na-ZSM-5 [12] [13] and the oxidation potential of trans-1 (E ox ഠ 1.5 V vs. SCE), [16] one-electron oxidation might appear to be a reasonable first step. However, the recent realization that Na-ZSM-5 contains Lewis and Brønsted acid site [24] suggests that protonation, yielding a 1,3-diphenylpropyl carbenium ion, 8 ϩ , must also be considered; this species should be readily deprotonated. As for the oxidation product, the significant electrostatic fields inside the zeolite channels may favor the ring-opened bifunctional species, 1…”