Dioxygen Activation by Internally Aromatic Metallacycle: Crystallographic Structure and Mechanistic Investigations

Activation of Dioxygen by Halocarbon Ions

Tandem mass spectrometry is used to show that low energy collisions of ionized halocarbenes, including CBr2 and CBrCl•+, with molecular oxygen lead to (i) decarbonation with formation of the dihalogen molecular cation and (ii) oxygenolysis yielding BrCO+. Both reactions may occur via the same ion-molecule addition product of molecular oxygen and the ionized carbene. Reaction is favored at low c...

Crystallographic investigations of biotin and carboxybiotin derivatives.

The structures of a family of biotin and carboxybiotin derivatives have provided information on the mechanism of biotin action. The ureido moiety of the uncarboxylated cofactor is polarized and able to interact with ions and polar molecules; intermolecular interactions in the biotin derivatives suggest biochemical mechanisms resulting in nucleophilic activation to the enol tautomer. N1' carboxy...

CRYSTALLOGRAPHIC, MORPHOLOGICAL AND W-H MODELS INVESTIGATIONS ON Mn SUBSTITUTED ZnO NANOCRYSTALS

Mn doped ZnO nanocrystals were prepared by co-precipitation route sintered at 450 °C temperature. XRD results indicate that the samples having hexagonal (wurtzite) structure. From X-ray data it is found that the lattice parameters increase with increasing Mn concentration. The X-ray density decreases with increasing Mn concentration of Zn 1-x Mnx O nanocrystals. It indicates that the Mn...

Dioxygen Activation by Enzymes Containing Binuclear Non-Heme Iron Clusters.

Dioxygen activation in soluble methane monooxygenase.

The controlled oxidation of methane to methanol is a chemical transformation of great value, particularly in the pursuit of alternative fuels, but the reaction remains underutilized industrially because of inefficient and costly synthetic procedures. In contrast, methane monooxygenase enzymes (MMOs) from methanotrophic bacteria achieve this chemistry efficiently under ambient conditions. In thi...