Hydrogen unconventional

Both the production of hydrogen from coal and the production of oil from unconventional resources (oil sands, oil shale, CTL, GTL) result in high C02 emissions and substantially increase the carbon footprint of fuel supply, unless the C02 is captured and stored. While the capture of C02 at a central point source is equally possible for unconventionals and centralised hydrogen production, in the case of hydrogen, a C02-free fuel results, unlike in the case of liquid hydrocarbon fuels. This is all the more important, as around 80% of the WTW C02 emissions result from the fuel use in the vehicles. If CCS were applied to hydrogen production from biomass, a net C02 removal from the atmosphere would even be achievable. 

With the basic (albeit unconventional) tools at hand, we will focus in the following on the detection of key intermediates with standard NMR and the application of the PHIP method to mechanistic studies of enantioselective enamide hydrogenations. 

Hydrogen bonds [3] can be classified as nonconventional (or nonclassical), when they are formed with the participation of nonconventional proton donors and/or unconventional proton acceptors ... 

R.H. Crabtree et al., A new intermolecular interaction Unconventional hydrogen bonds with element-hydride bonds as proton acceptor. Acc. Chem. Res. 29, 348-354 (1996)... 

The H H interactions (1.75-1.9 A) here and related systems are referred to as proton-hydride bonding by Morris (60-62) and dihydrogen bonding by Crabtree (63-65), who along with others (66-68) have studied or reviewed such unconventional hydrogen bonds that include M-H H-M, M-H H-X, and X-H a interactions in general (X = C, N, P, 0, etc). These complexes represent intermediates in the heterolytic splitting of H2 and illustrate both the basicity of the M-H... 

Kar T, Scheiner S (2006) Cooperativity of conventional and unconventional hydrogen bonds involving imidazole. Int J Quantum Chem 106 843-851... 

Hydrogen can be produced, in theory, from a variety of sources including primary energy sources and water. In the absence of significant technological breakthroughs in renewable electricity production or unconventional hydrogen-production techniques, natural gas and other fossil fuels will likely continue to be used to create the vast majority of hydro-... 

Forosamine is an amino sugar component of the antibiotic Lepicidin. Since Le-picidin is sensitive to acid and catalytic hydrogenation, an Fmoc group was selected to protect the amino function. A rather unconventional method was used to introduce it [Scheme 8.94].230 A Curtius rearrangement on the acyl azide derived from carboxylic acid 94.1 proceeded with retention of configuration to give the isocyanate intermediate 94.2 that was trapped with 9-fluorenylmethanol to afford the N-Fmoc derivative 94J in 72% yield. 

Dihydrogen complexes (5) such as [Cr(H2)(CO)5] are covered in a separate article. Dihydrogen bonding, the tendency of an MH bond to act as proton acceptor in an unconventional hydrogen bond with an OH or NH group, is also covered in a separate article, see Hydrogen Bonding). ... 

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