Metallization under high pressures

Commercial reforming typically occurs at high hydrogen excess. This minimizes coke formation but also affects the products, particularly hydrogenolysis. The role of a second metal under high pressure conditions has been examined. The results of comparing Pt... 

In airless hydraulic) atomization the paint is forced through a slit nozzle of hard metal under high pressure (8-40 MPa). On account of the high degree of turbulence, the paint stream disintegrates immediately after leaving the fluid tip. A similar atomization process occurs in spray cans where the paint pressure is produced by the propellant gas. 

Thanks to their simplicity, the structures of most elements at ambient conditions have been established in early days of X-ray crystallography and are excellently reviewed in a number of books [1-5]. However, changes in thermodynamic conditions can drastically affect the structure of solids, e.g. transforming an atomic lattice into gaseous molecules at high temperature or, on the contrary, converting a molecular crystal into a metal under high pressure. Increase of coordination number (Na) of... 

They exhibit valences between 3 and 3.4. Beaurepaire et al. (1984) and Parks et al. (1983) studied the Lm absorption in Ce(Pdi- tTjc)3 (T = Ag,Rh,Y). The volume dependence of the Ce valence in these alloys is found to be similar to the valence-volume relationship measured in Ce metal under high pressure (Rohler 1985a). At small volumes the valence is pinned at about 3.3. 

N. A. Bendeliani, Phase transformations of trifluorides of transition metals under high pressure, Izvestiya AN SSSR, Neorgan. Mater., 20, 1726-1729 (1984) (in Russian)... 

Takemura K, Minomura S, Shimomura O, Fu]ii Y and Axe J D 1982 Structural aspects of solid iodine associated with metallization and molecular dissociation under high pressure Phys. Rev. B 26 998... 

Low Pressure Syntheses. The majority of metal carbonyls are synthesized under high pressures of CO. Early preparations of carbonyls were made under superpressures of 1 GPa (ca 10,000 atm). Numerous reports have appeared in the Hterature concerning low pressure syntheses of metal carbonyls, but the reactions have been restricted primarily to the carbonyls of the transition metals of Groups 8—10 (VIII). A procedure for preparing Mn2(CO)2Q, however, from commercially available methylcyclopentadienyknanganese tricarbonyl [12108-13-3] and atmospheric pressures of CO has been reported (117). The carbonyls of mthenium (118,119), rhodium (120,121), and iridium (122,123) have been synthesized in good yields employing low pressure techniques. In all three cases, very low or even atmospheric pressures of CO effect carbonylation. Examples of successful low pressure syntheses are... 

Low Oxidation State Chromium Compounds. Cr(0) compounds are TT-bonded complexes that require electron-rich donor species such as CO and C H to stabilize the low oxidation state. A direct synthesis of Cr(CO)g, from the metal and CO, is not possible. Normally, the preparation requires an anhydrous Cr(III) salt, a reducing agent, an arene compound, carbon monoxide that may or may not be under high pressure, and an inert atmosphere (see Carbonyls). 

C06-0119. Gases are sold and shipped in metal tanks under high pressure. A typical tank of compressed air has a volume of 30.0 L and is pressurized to 15.0 bar at J — 298 K. What work had to be done in filling this tank if the compressor operates at 15.0 bar (Hint What volume did the air occupy before it was compressed )... 

Since then seven further superconducting (at low temperatures and/or under high pressures) dmit-based complexes with Ni or Pd as metal, synthesized via electrocrystallization, have become known. The donor-acceptor complex a-(EDT-TTF)[Ni(dmit)2]2 is the first ambient pressure superconductor with Tc = 1.3 K.257 ... 

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