Carbon formation, platforming

For example, treatment of MgO-supported [HIr4(CO)n] in flowing He at 573 K caused essentially complete removal of the CO ligands, as shown by IR and EXAFS spectra, with the Ir4 tetrahedra remaining essentially intact, as shown by EXAFS spectra [12]. IR spectra indicated the formation of carbonate and formate on the basic MgO, which evidently was not an inert platform [19]. When the decarbonylation took place in the presence of H2, the iridium aggregated into larger clusters more readily than when the de-... 

The preference for the /3-silyl isomer product complements methods available for hydrostannation of alkynes, for which the a-stannyl regioisomer is formed preferentially.70 7011 70c In addition, the /3-silyl products serve as the platform for a tertiary alcohol synthesis (Scheme 15). Upon treatment of vinylsilanes such as B with tetrabutylam-monium fluoride (TBAF) in DMF at 0 °C, a 1,2 carbon-to-silicon migration occurs, affording the tertiary heterosilane E. Oxidation of the C-Si bond then provides the tertiary alcohol. Good 1,2-diastereocontrol has been demonstrated for y-alkoxy substrates, as in the example shown. The studies suggest that the oxidation of the sterically demanding silane intermediate is facilitated by the intramolecular formation of a silyl hemiketal or silyllactone for ketone or ester substrates, respectively.71... 

Enantiomerically pure d.v-1 -amino-2-indanol and its derivatives have been used as ligands in numerous catalytic asymmetric carbon-hydrogen, carbon-carbon, and carbon-heteroatom bond formation reactions. The conformationally constrained indanyl platform has emerged as a particularly valuable backbone in a variety of catalytic processes leading to high levels of asymmetric induction. The aminoindanol 1 has also been used as a resolution agent (Chapter 8) as well as a chiral auxiliary (Chapter 24). For the synthesis of 1 see Chapter 24. 

The sedimentary section of the U.S. southern midcontinent consists in large part of Paleozoic platform carbonate rocks interbedded with shale and subordinate sandstone. As documented below, a large volume of the Paleozoic carbonate rocks in this region is enriched in arsenic, as well as lead, zinc, copper, cobalt, molybdenum, and nickel compared to surrounding carbonate strata (Erickson et al., 1981 Lee and Goldhaber, 2001). In plan view this trace-mineralized area extends over thousands of square kilometers. The widespread metal enrichment process was related to the formation of much more spatially localized ore districts. These districts consist of economic concentrations of the ore elements zinc and lead, and to a lesser extent copper, cobalt, and barium that occur in the platform... 

Formation, which characterizes a period of relative tectonic quiescence. The passive marine margin sequence (Albian to Recent) is characterized by the development of a shallow-water carbonate platform (Macae Formation), which prograded into deepwater siliciclastics (Campos Formation). 

Moss, S. Tucker, M.E. (1995) Diagenesis of Barremian-Aptian platform carbonates (the Urgonian Limestone Formation of SE France) near-surface and shallow-burial diagenesis. Sedimentology, 42, 853-874. 

The availability of ECL technology from instrument providers such as Meso Scale Discovery (MSD) has enabled practical applications of electrochemiluminescent assays. The MSD platform uses carbon electrode plates that are available uncoated or coupled with biotin or streptavidin. Thus, the platform may be used with direct, indirect, and bridging formats. 

Studies have shown that the storage of carbon dioxide is possible in various geological settings. The main candidates are sedimentary basins, e.g., oil and gas reservoirs (working or abandoned), deep unmineable coal-seams and saline formations (aquifers). Sub-surface storage can take place at both on-shore and off-shore locations access to the latter is via pipelines from the shore or from off-shore platforms. Other prospective sites for storage include salt caverns, basalts, oil/gas shales and disused mines. The various options are shown schematically in Figure 3.4. 

The majority of the oils in the southern Paleozoic province were formed during the Paleozoic when burial of the source rocks exceeded 2-3 km. However, the Paleozoic traps were destroyed by the Hercynian erosion and the hydrocarbons then were able to dissipate. During the Mesozoic, throughout the subsidence of the northern and northeastern parts of the platform, the burial depths again reached the conditions necessary for the generation of hydro carbons. During the Cretaceous (post-Aptian) the depth of burial of the source rocks reached values of about 3 km which favoured mainly the formation of gas. 

---