Carbon element formation

Direct metallation of o-halogenophenoxyelement derivatives of silicon, tin, and phosphorus leads to an unstable metallated intermediate which undergoes a rapid 1,3-rearrangement under element-carbon bond formation. This type of reaction seems to be a general method for the synthesis of hydroxyphenyl element derivatives [1-4], We have studied the influence of different organoelement groups on the reaction pathway. The yield increases in the sequence R3Sn < R2P < RjSi P(0)(0R)2. 

The main components of marine sediments are inorganic aluminosilicate minerals which are usually accumulated on the sea floor by river and other geological activities, and also skeletons and shells of marine organisms (mainly calcium carbonate and silica) [2]. Of course, some metal salts or particulates which precipitate from seawater form new minerals, e.g. manganese nodules [2]. The chemical compositions of the three principal types of sediments in the ocean are shown in Table 12 [105], Most of the sediments found in the deep-sea floor are mixtures of these three principal minerals. Study of the sediments in the oceans and seashores can provide important data related to geochemical, oceanographical or biological circulation and deposition of elements, formation and distribution of marine sediments, and exploitation of marine resources. 

Hydride cleavage of carbon-element tr-bonds frequently results in C—H bond formation, although often the other cleavage product is of primary interest, e.g. ... 

Carbon fibres are manufactured from rayon and polyacrylonitrile. Carbon fibres can be heated up to 1500°C and contains up to 95% of elemental carbon. Graphite fibres can be heated above 2500 C with 99% carbon. The formation of carbon fibres from polyacrylonitrile is outlined in Fig. 1 -34. Carbon fibres are used in the aerospace industry, in compressor blade to jet engines, helicopter rotor- blades, aircraft fuselage structures, golf-club shafts, cross-bows for archery and in high speed reciprocating parts in loom. 

Is it fascinating to know that the polyynes are considered the key precursors in the formation of polycyclic aromatic hydrocarbons and soot in combustion flames and that a similar mechanism of carbon dust formation can be applied (without flames) to explain the formation and the abundance of elemental carbon in our galaxy. Carbon dust represents about 3% of the... 

One additional stage of element formation may also occur during helium burning, the reaction between an alpha particle and a carbon nucleus to produce an oxygen nucleus ... 

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