High pressures, reactions of the

Kolbe-Schmitt reaction (Section 24.10) The high-pressure reaction of the sodium salt of a phenol with carbon dioxide to give an o-hydroxybenzoic acid. The Kolbe-Schmitt reaction is used to prepare salicylic acid in the synthesis of aspirin. 

On the industrial (multitonne) scale it can also be prepared by direct high-pressure reaction of the elements or preferably via the intermediate formation of the Na analogue. 

Quack M 1984 On the mechanism of reversible unimolecular reactions and the canonical ( high pressure ) limit of the rate coefficient at low pressures Ber. Bunsenges. Phys. Chem. 88 94-100... 

Higher molecular primary unbranched or low-branched alcohols are used not only for the synthesis of nonionic but also of anionic surfactants, like fatty alcohol sulfates or ether sulfates. These alcohols are produced by catalytic high-pressure hydrogenation of the methyl esters of fatty acids, obtained by a transesterification reaction of fats or fatty oils with methanol or by different procedures, like hydroformylation or the Alfol process, starting from petroleum chemical raw materials. 

High Pressure Study of the Methanol Reaction Using Deuterated Methanols... 

Results. In the past two years we have undertaken a high pressure examination of the ion-molecule reactions occurring in a series of polar molecules—namely, methylamine, methanol, ethylamine, and ethanol (3). In all cases, the major secondary ion is the (parent +1) ion and in the first two cases, it is the only secondary ion. All hydrogenic primary ions undergo the general reaction,... 

The filament operates in the same way as a filament in chemical ionization by generating reactive species from solvent molecules in the high-pressure region of the source. These ionize the analyte by ion-molecule reactions (see Section 3.2.2 above). The discharge electrode, which may also provide more stable conditions when the mobile phase contains a very high proportion of water, provides the electrons required to generate the reactive species by means of a continuous gas discharge. 

In an unpublished study, Grieger and Hansel have used absorbance measurements to monitor the progress of the reaction forming an enzyme-substrate complex of imidazole (S) and metmyo-globin (E) at high pressures. Formation of the enzyme-substrate complex (ES) may be represented by the following equation... 

The high-pressure reaction of A-methylpiperidine with 4-chloronitrobenzene yields A-(4-nitrophenyl)piperidine (equation 117) 2-chloronitrobenzene and chloro-2,4-dinitrobenzene behave analogously. A-Methylpyrrolidine and 4-chloronitrobenzene afford a mixture of A-(4-nitrophenyl)pyrrolidine and the product 342 of ring scission (equation 118)385. 

Haber received the Nobel prize for Chemistry in 1918. Bosch received a Nobel prize in 1931 for his work on high pressure reactions. Today the Haher-Bosch process is used to manufacture virtually all the ammonia that is produced in the world. Plants are usually located near a source of natural gas, which is used to obtain the hydrogen gas. 

Figure 24. X-ray diffraction pattern (in the inset the 2D image) of the polyethylene sample recovered by the laser-assisted high-pressure reaction in the pure liquid monomer. The two measured sharp lines nicely fit the polymer diffraction pattern having a orthorhombic cell (Pnam) defined by the lattice parameters reported in the figure.

The product obtained from the high-pressure reaction of benzene has been identified as amorphous [309]. The amorphous character of the sample prevents the obtainment of the Raman spectra. Other physical-chemical properties of the reaction product are the following refractive index n = 1.75 density p = 1.39 g/cm elastic constant Bq = 80 GPa optical gap 2.5 eV. These values must to be considered only as typical values of the properties because, as described above, the reaction product is reported to change according to the... 

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