The role of twist-boat conformers of cyclohexanones in hydride reductions was explored. The hydride reductions of a cis-2,6-disubstituted N-acylpiperidone, an N-acyltropinone, and tert-butylcyclohexanone by lithium aluminum hydride and by a bulky borohydride reagent were investigated computationally and compared to experiment. Our results indicate that in certain cases, factors such as substrat...

The hydriding kinetics of hydrogen storage materials in the two-phase regions have been studied. It is believed that the hydriding process is best classified into three steps: dissolution of hydrogen into the alloy or its hydride; diffusion of hydrogen atoms through the alloy or its hydride phase; and nucleation and growth of B-hydride (hydride depositing from supersaturated a-solid solution). ...

Mono-, di- and trinuclear zirconium hydride species have been isolated in the treatment of amido complexes [Zr(η5-C5Me5)(NMe2)nCl3-n] (n = 3, 1) with amine-borane adducts NHR2BH3 (R2 = Me2, HtBu). The reactions involve the formation of amidoborane ligands with ZrH-B interactions which readily undergo β-hydride elimination to give hydride functions.

A programme of examining hydride blisters created in the laboratory on zircaloy pressure tubes and that in the irradiated pressure tube from one of the PHWR , which was suspected to have developed hydride blisters, was undertaken using neutron radiography. It was observed that a zirconium hydride blister of nearly 0.35% of job thickness could be detected using neutron radiography. This work ser...

Although its value varies with the microstructure, hysteresis always accompanies hydride formation and decomposition in Pd(pure)-H, e.g., it is present even in nano-crystalline and thin films. Internal oxidation of Pd0.93Cr0.07 alloys leads to a pure Pd matrix containing nano-crystalline chromia precipitates. The characteristic hysteresis of Pd-H almost disappears in this form of Pd. The reason...

Hydride transfer plays a crucial role in a wide range of biological systems. However, its mode of action (concerted or stepwise) is still under debate. Light-dependent NADPH: protochlorophyllide oxidoreductase (POR) catalyzes the stereospecific trans addition of a hydride anion and a proton across the C17 -C18 double bond of protochlorophyllide. Time-resolved absorption and emission spectroscop...

γ-hydride precipitation and growth in a zirconium bi-crystal were simulated using a phase field kinetic model. The temporal evolution of the spatially dependent field variables is determined by numerically solving the time-dependent Ginzburg-Landau equations for the structural variables and the Cahn-Hilliard diffusion equation for the concentration variable. The morphology evolution of γ-hydrid...

The effect of hydrogen on the corrosion and stress corrosion cracking of the magnesium AZ91 alloy has been investigated in aqueous solutions. Hydrogen produced by corrosion in water diffuses into, and reacts with the Mg matrix to form hydride. Some of the hydrogen accumulates at hydride/Mg matrix (or secondary phase) interfaces as a consequence of slow hydride formation and the incompatibility ...

This paper focuses on developing an efficient fuel storage and release method for hydrogen using lithium hydride hydrolysis for use in PEM fuel cells for low power sensor network modules over long durations. Lithium hydride has high hydrogen storage density and achieves up to 95e100% yield. It is shown to extract water vapor freely from the air to generate hydrogen and has a theoretical fuel sp...