Hydrides hydrogen

Hardy and Linnett (59) studied the heterogeneous recombination of atomic hydrogen at room temperature on nickel and nickel alloy foils. They did not find any similarity to the behavior of palladium and its alloys with gold studied earlier (35). There was no evidence that, as a result of exposure to atomic hydrogen, hydride was formed in any metal catalyst investigated with a resulting change in the activity of the initial parent metal catalysts. 

Terry, L.E. "Hydrogen-Hydride Absorption Systems and Methods for Refrigeration and Heat Pump Cycles" US Patent U,055,962 Nov. 1, 1972. 

An alternative synthesis of ( )-a- and ( )--y-lycoranes (57 and 93) commenced with the 2-oxocyclohexyl acetic acid derivative 114 obtained by the alkylation of the enamine derived from 113 (Scheme 10) (116). Refluxing the oxime of 114 with zinc dust in glacial acetic acid afforded a mixture of the lactams 115, 116, and 117 in an approximate ratio of 4 6 3. The structure of 115 was verified by catalytic hydrogenation to give the lactam 118, which had previously been converted to ( )-a-lycorane (57). When the lactam 116 was subjected to sequential catalytic hydrogenation, hydride reduction, and Pictet-Spengler cyclization, ( )-y-lycorane (93) was obtained. A more efficient route to ( )-a-lycorane (57) involved refluxing the ketone 114 first with benzylamine in xylene and then with 87% formic acid to furnish the unsaturated lactam 119. 

There are three main nonbonding interactions presented within this classification (Fig. 12.12) hydrogen, hydride, and halogen bonds. DHB and halogen-hydride are... 

Keywords hydride, hydrogen, hydride bed, hydride sorber, hydride heat pump. 

Zeolites are not typically used in Lewis acid type catalysis due to the absence of Lewis acid centers in zeolites. This is due to the coordination of the Al-site to four lattice-oxygens in a perfect zeolite framework. It has, however, been shown for zeolite Beta that the aluminum atom can reversibly move between a framework Brpnsted acid site and a framework-grafted Lewis-acid site.70 Accordingly, Creyghton et al. showed that zeolite Beta is active in the Meerwein-Ponndorf-Verley reduction (MPV) of ketones (scheme 4).71 In this reaction a hydrogen hydride transfer reaction between an alcohol and a ketone takes place. 

The synthesis of hydrido species can involve interactions with molecular hydrogen, hydride sources such as NaBHt or LiAlH4, alcohols and other organic sources. Some representative syntheses are as follows. 

P. B. Venuto (Mobil Oil, Paulsboro, N. J. 08066) Even though your butene reactions occur at low temperatures—relative to thermal free radical reactions—with the presence of polyvalent transition metal ions, radical-type or electron unpairing-type reactions may certainly occur. In your reactions of butene over CeX at 190 °C, did you notice any evidence of an intermolecular hydrogen (hydride) type reaction, as evidenced by light paraffins in the gas phase and hydrogen-deficient species (aromatics) within pores ... 

In terms of kinetics and mechanisms, electroless deposition processes have many similarities. In an attempt to analyze the electroless deposition, several mechanisms such as atomic hydrogen, hydride ion, metal hydroxide, electrochemical, and universal have been proposed.1-3 It is important to note that these mechanisms were developed for cases of nickel and copper electroless deposition, which were the most widely studied metals in this respect. Based on the proposed mechanisms, most of the features of electroless deposition can be explained. However, there are some characteristics of electroless deposition, which cannot be explained using these mechanisms. The major problems arise when attempting to generalize the proposed models explaining the mechanistic aspects. 

Buchner, H., The Hydrogen/Hydride Energy Concept, in Hydrides for Energy Storage, Anderson A.F. and Maeland, A.J. Editors, 1978, Pergamon Oxford, p. 569-599. 

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