Abstract. Photo-chemically induced dynamic nuclear polarization (photo-CIDNP) was used to observe the light-induced disproportionation reaction of 6,7,8-trimethyllumazine starting out from its triplet state generate a pair radicals comprising one-electron reduced and oxidized species. Our evidence is based on measurement two marker proton hyperfine couplings, Aiso(H(6α)) Aiso(H(8α)), which we c...

A carbon nanotube-gold nanohybrid was used as catalyst for the reduction of molecular oxygen in acidic and alkaline media, the relevant cathode reaction in fuel cells. In alkaline medium, the nanohybrid exhibits excellent activity with a dominant 4e(-) reduction of O2 and low overpotential requirement compared to previously reported nano-gold materials. This property is linked to its capability...

Chlorodifluoromethane (R-22), the most abundant freon in atmosphere, was subjected to successful hydrodechlorination presence of palladium supported on ?-alumina, at a relatively low reaction temperature (180 °C). The combination catalytic actions alumina (performing dismutation) and Pd nanoparticles (catalyzing C–Cl bond splitting hydrogen) results transformation into valuable, chlorine-free p...

In response to the increasing social demand for clean and environmental friendly procedures, recent years have witnessed a dramatic growth in the search for selective chemical processes with 100% atom economy. Among them, the catalyzed coupling of aldehydes to the corresponding esters (Tishchenko reaction, Scheme 1) is key for the synthesis of these valuable chemicals. 1] This reaction and the ...

Pyruvic acid is one of the most reactive substances among those of importance in cellular metabolism. When carbohydrate is split during fermentation, pyruvic acid is the main end-product of the resulting series of phosphorylated oxidation-reductions. It thus becomes the immediate source for the formation of both lactic acid and alcohol. Pyruvic acid is decarboxylated by yeast; it may react with...

Arylmagnesium and -calcium reagents are easily accessible; however, ether degradation processes limit storability, especially of the calcium-based heavy Grignard reagents. Ortho-bound substituents with phosphanyl donor sites usually block available coordination sites and stabilize such complexes. The reaction of bromo-2,6-bis(diphenylphosphanylmethyl)benzene (1a) with magnesium in tetrahydrofur...

Superoxide dismutase catalyzes the decay of 0~~, generated by pulse radiolysis. The enzymatic reaction was 6rst order with respect to enzyme and to 0~~ and the rate constant, which was 2.3 X lo9 M-' s-l at pH 7.0 and ZO-25”, was not much affected by pH, in the range 4.8 + 9.5. Boiling the enzyme or reversibly removing its copper prosthetic group caused loss of catalytic activity. EDTA had no ef...