The Oxidative Power of Protonated Hydrogen Peroxide

Abstract

A simple hydride‐transfer mechanism to produce alkyl cations occurs when isolated protonated hydrogen peroxide (HOOH2+) attacks the C−H bonds of alkanes (except methane) [Eq. (1)]. The chemical properties of HOOH2+, which may serve as a model of the central catalytic motif of key biological systems, have been studied for the first time.

9 Organic gas phase ion chemistry

“…Uggerud and co-workers have used CH 4 chemical ionization on H 2 O 2 to generate protonated hydrogen peroxide, HOOH 2 ϩ . The unimolecular and bimolecular reactivity of HOOH 2 ϩ was studied using a sector instrument (EBEB) and an FT-ICR apparatus 225. Metastable HOOH 2 ϩ ions having internal energy sufficiently close to the dissociation threshold decompose spontaneously to form H 3 O ϩ and 3 O, consistent with previous theoretical predictions that ground state singlet HOOH 2 ϩ will decompose with loss of an oxygen atom via a spin change mechanism.…”

Fluorinated Alcohols Enable Olefin Epoxidation by H2O2: Template Catalysis

“…Strong acids protonate the peroxide and promote a heterolytic mechanism. Indeed, experimental and computational studies indicate that protonated hydrogen peroxide, H 3 O 2 + , is a very powerful oxidant. , By contrast, weak acids such as CF 3 COOH appear to participate in the activation of H 2 O 2 in their nondissociated forms and catalyze the oxygen insertion by hydrogen bonding to the oxidant . Recently, one of us and others have demonstrated that 1-octene, which is notoriously difficult to epoxidize, undergoes epoxidation under mild conditions when H 2 O 2 is employed in fluorinated alcoholic solutions, e.g., CF 3 CH 2 OH and (CF 3 ) 2 CHOH.…”

Reaction dynamics simulations of the identity SN2 reaction H2O + HOOH2+→ H2OOH++ H2O. Requirements for reaction and competition with proton transfer

“…In the accompanying experimental work, reactions between 18 O isotope labelled water and HOOH 2 1 were investigated using FT-ICR mass spectrometry. 3 Despite the potentially promising S N 2 mechanism, it was not possible to observe any product ion incorporating 18 O. Instead the proton transfer (reaction 4) is dominating.…”

“…The reactivity of protonated hydrogen peroxide has recently been the subject of several studies. [1][2][3][4] Gas phase experiments, supported by quantum chemical and reaction dynamics simulations, have demonstrated that this species is a strong oxidant, and that the mechanism of action is by hydride abstraction from the substrate molecule, as in the reaction with ethane:…”

“…It was also realized that a third reaction type could be achievable for HOOH 2 1 , namely the S N 2 reaction. 3 In analogy with the isoelectronic CH 3 OH 2 1 , which easily undergoes S N 2 reactions at carbon, the ion HOOH 2 1 has the potential to react at the hydroxyl oxygen. To probe this, we conducted MP2/6-31G(d,p) ab initio quantum chemical calculations of the prototypical identity substitution reaction…”