Application of the Marcus Cross Relation to Hydrogen Atom Transfer Reactions

Roth, Justine P.; Yoder, Jeffrey C.; Won, Tae‐Jin; Mayer, James M.

doi:10.1126/science.1066130

Cited by 200 publications

(269 citation statements)

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“…Calculation capacity limitations of our DFT simulation necessitated the examination of an Au 32 and Au 12 Pd 20 cluster as a first step and the charge distributions of the cluster was simulated. The results of the calculation confirm that charge heterogeneity exists even in the monometallic Au clusters and the alloy structure of Au with Pd increases the charge heterogeneity of the nanoparticle surface, as can be seen from the comparison of two lines in Fig 1. Considering the electronegativity of the two metals, this charge distribution is to be expected and in agreement with previous reports [8]. Fig.…”

Section: Benzyl Alcohol Oxidationsupporting

confidence: 78%

The Study on Activity Enhancement of Gold and Palladium Alloy Nanoparticles in Comparison with Monometallic Catalysts

Cui¹,

Zhang²,

Lu³

et al. 2017

Proceedings of the Advances in Materials, Machinery, Electrical Engineering (AMMEE 2017)

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Abstract. Alloy nanoparticles (NPs) of gold and palladium were found to be more active in oxidation of benzyl alcohols than supported gold or supported palladium NPs. The enhanced activity of benzyl alcohol oxidation at the surface of the alloy NPs can be explained by the charge heterogeneity. To confirm the charge heterogeneity, simulations using the Density function theory (DFT) were carried out. TEM, EDX, UV-Vis and XPS were also employed to investigate the properties of the gold and palladium alloy NPs as well as gold, palladium monometallic catalysts.

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Section: Benzyl Alcohol Oxidationsupporting

confidence: 78%

The Study on Activity Enhancement of Gold and Palladium Alloy Nanoparticles in Comparison with Monometallic Catalysts

Cui¹,

Zhang²,

Lu³

et al. 2017

Proceedings of the Advances in Materials, Machinery, Electrical Engineering (AMMEE 2017)

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“…3 is significantly less than a factor of 10 but is at least in the correct direction. Deviations from the quantitative predictions of the cross-relation are not uncommon in ET (or HAT) processes (44,46).…”

Section: Discussionmentioning

confidence: 99%

Probing concerted proton–electron transfer in phenol–imidazoles

Markle

Rhile

DiPasquale

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

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122

188

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A series of seven substituted 4,6-di-tert-butyl-2-(4,5-diarylimidazolyl)-phenols have been prepared and characterized, along with two related benzimidazole compounds. X-ray crystal structures of all of the compounds show that the phenol and imidazole rings are close to coplanar and are connected by an intramolecular ArOH⅐ ⅐ ⅐N hydrogen bond. One-electron oxidation of these compounds occurs with movement of the phenolic proton to the imidazole base by concerted proton-electron transfer (CPET) to yield fairly stable distonic radical cations. These phenol-base compounds are a valuable system in which to examine the key features of CPET. Kinetic measurements of bimolecular CPET oxidations, with E rxn between ؉0.04 and ؊0.33 V, give rate constants from (6.3 ؎ 0.6) ؋ 10 2 to (3.0 ؎ 0.6) ؋ 10 6 M ؊1 s ؊1 . There is a good correlation of log(k) with ⌬G°, with only one of the 15 rate constants falling more than a factor of 5.2 from the correlation line. Substituents on the imidazole affect the (O-H⅐ ⅐ ⅐N) hydrogen bond, as marked by variations in the 1 H NMR and calculated vibrational spectra and geometries. Crystallographic dO⅐ ⅐ ⅐N values appear to be more strongly affected by crystal packing forces. However, there is almost no correlation of rate constants with any of these measured or computed parameters. Over this range of compounds from the same structural family, the dominant contributor to the differences in rate constant is the driving force ⌬G°.Marcus Theory ͉ oxyl radicals ͉ proton-coupled ͉ ROS ͉ tyrosyl radicals R eactive oxygen species (ROS) exhibit a wide range of reactivity, from the extraordinarily potent hydroxyl radical to much more inert aryloxyl and ascorbyl radicals. These species are sometimes categorized by their redox potentials at pH 7, but most reactions of ROS do not proceed by simple electron transfer (ET). Typically, ROS react by proton-coupled electron transfer (PCET), as in the disproportionation of hydrogen peroxide to dioxygen and water and the interconversions of tyrosyl radicals and tyrosine residues. Understanding the detailed mechanisms of these and other PCET

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“…Others use both words, depending on the context, a practice we will follow here.) Marcus theory has also been extended to proton transfer and other chemical reactions, 57,120,262,303,308,309,[311][312][313][314][315][316][317][318][319][320][321][322][323][324][325][326][327][328] which typically involved stronger coupling, i.e., the adiabatic case.…”

Section: Modelsmentioning

confidence: 99%