A C-C bonded phenoxyl radical dimer with a zero bond dissociation free energy.

The 2,6-di-tert-butyl-4-methoxyphenoxyl radical is shown to dimerize in solution and in the solid state. The X-ray crystal structure of the dimer, the first for a para-coupled phenoxyl radical, revealed a bond length of 1.6055(23) Å for the C4-C4a bond.

Titanium and zinc oxide nanoparticles are proton-coupled electron transfer agents.

Oxidation/reduction reactions at metal oxide surfaces are important to emerging solar energy conversion processes, photocatalysis, and geochemical transformations. Here we show that the usual description of these reactions as electron transfers is incomplete. Reduced TiO(2) and ZnO nanoparticles in solution can transfer an electron and a proton to phenoxyl and nitroxyl radicals, indicating that e(-) and H(+) are coupled in this interfacial reaction.

Electron transfer between colloidal ZnO nanocrystals.

Colloidal ZnO nanocrystals capped with dodecylamine and dissolved in toluene can be charged photochemically to give stable solutions in which electrons are present in the conduction bands of the nanocrystals. These conduction-band electrons are readily monitored by EPR spectroscopy, with g* values that correlate with the nanocrystal sizes. Mixing a solution of charged small nanocrystals (e(-)(CB):ZnO-S) with a solution of uncharged large nanocrystals (ZnO-L) caused changes in the EPR spectrum indicative of quantitative electron transfer from small to large nanocrystals.

Gold(III) and platinum(II) polypyridyl double salts and a general metathesis route to metallophilic interactions.

Nine new double-salt compounds have been prepared and six crystal structures are reported that demonstrate a general metathesis route to double-salt compounds with metallophilic interactions. The compounds contain [Pt(terpy)X]+ or [Au(bpy)X2]+ cations, Au(III) or Au(I) anions such as [AuBr4]- or [AuCl2]-, and are prepared in water and recrystallized from organic solvents. In all crystallographically characterized cases, there exist metallophilic interactions between cations and anions, demonstrating the power of this general route.