Vapor synthesis

Nonpowder Synthesis. Many ceramic composites (qv) under iavestigation utilize reinforcing ceramic whiskers or fibers to achieve toughening (19). Whiskers (17,19,20) are produced by vapor-synthesis techniques. SiC whiskers can be produced by the rice hull or vapor—soHd (VS) method whereby rice hulls are pyrolyzed to produce a mixture of carbon, C, and Si02, and whiskers are produced by directional growth by vapor... 

The metal-vapor synthesis, involving co-condensation of nickel vapors, r-BuC = P, and 1,2,4-triphospholyl system leads to the mixed-ligand species 178 (94AGE2330). 

Co-condensation of Hf and Zr atoms from an electron-gun evaporation device, with P(Me)3 and arenes at 77K gave good yields of the species [M(arene)2P(Me3)]. Metal vapor synthesis led to Fe(i7 -arene)L2 and Fe(i7 -arene)-(i7 -diene), where L is a phosphorus ligand. In addition, complexes of stoichiometry Fe(T) -diene)L3 (where L is again a... 

Dihydro-lH-l,5,2-azasilaboroles derive from the 2,5-dihydro-lH-l,2-aza-boroles ( 6.5.3.3) by substitution of the carbon neighboring N by a silicon atom. They may act as four-electron donors using electron density from the C=C double bond and the N atom. The B atom behaves as an acceptor center. Two pathways are known for complex synthesis reaction with a generated transition-metal complex fragment and reaction with metal atoms by the metal-vapor synthesis method. 

Azaborolyl sandwich complexes can be prepared by metal-vapor synthesis ( 6.5.3.1) ... 

Metal-vapor synthesis also prepares metallaboranes and metallacarboranes with oxidation of the metal. Thermally generated Ni, Co and Fe atoms react with the nido-carborane 2,6-C2B7H, and either cyclopentadiene, toluene, mesitylene, or... 

Dihydro-l,2-azaborolyl sandwich complexes, available by metal-vapor synthesis ( 6.5.3.3), can be prepared in a greater variety by reaction of metal halides with azaborolyl anions, e.g. " ° ... 

In this chapter the potential of nanostructured metal systems in catalysis and the production of fine chemicals has been underlined. The crucial role of particle size in determining the activity and selectivity of the catalytic systems has been pointed out several examples of important reactions have been presented and the reaction conditions also described. Metal Vapor Synthesis has proved to be a powerful tool for the generation of catalytically active microclusters SMA and nanoparticles. SMA are unique homogeneous catalytic precursors and they can be very convenient starting materials for the gentle deposition of catalytically active metal nanoparticles of controlled size. 

Blackborrow, J.R., and Young, D. In Metal Vapor Synthesis in Organometallic Chemistry Springer Verlag Berlin, 1979. 

Blackborow, J. R. Young, D. Metal Vapor Synthesis in Organo-... 

Cloke et al. presented the elegant metal-vapor synthesis for the preparation of linear 14 valence-electron complexes [M°(NHC)2] 73 (M = Ni, Pd, Pt) (Fig. 24a) [186]. The method was subsequently improved [187] and the interesting electronic and catalytic properties of Pd° and Pt° biscarbene complexes have been studied in detail [188-191]. 

Similar to chemical vapor deposition, reactants or precursors for chemical vapor synthesis are volatile metal-organics, carbonyls, hydrides, chlorides, etc. delivered to the hot-wall reactor as a vapor. A typical laboratory reactor consists of a precursor delivery system, a reaction zone, a particle collector, and a pumping system. Modification of the precursor delivery system and the reaction zone allows synthesis of pure oxide, doped oxide, or multi-component nanoparticles. For example, copper nanoparticles can be prepared from copper acetylacetone complexes [70], while europium doped yttiria can be obtained from their organometallic precursors [71]. 

Swihart MT (2003) Vapor synthesis of nanoparticles. Curr Opin Colloid Interf Sci 8 127-133... 

Electron damage and electronic excitation effects. Electron bombardment heating is suitable for the evaporation of all metals under vacuum, but its use in metal vapor synthesis can create problems because of electrons interacting with substrate molecules to form product-destroying ions or radicals. Electron... 

One of the modem methods is associated with the application of pyrophoric metals formed, for examle, as a result of low-temperature gas phase codeposition with toluene vapor (MVS-metal vapor synthesis) [757],... 

Bis(amido) phosphine-donor complexes, with Zr(IV), 4, 816 Bis(amido) pyridines, with Zr(IV) and Hf(IV), 4, 790 Bis(aminoalkylidyne) complexes, diiron carbonyl complexes with cyclopentadienyl ligands, 6, 248-251 Bisaminosilylenes, in molybdenum carbonyls, 5, 406 Bis(tj-arc nc) complexes, as metal vapor synthesis milestone, 1, 236... 

Bis(benzamidinate)zirconium catalysts, for stereoselective propylene polymerization, 11, 708 Bis(r -benzene)tungsten, as metal vapor synthesis milestone, 1, 236... 

Cobalt-silicon bonds, in hydridocobalt complexes, 7, 5 Cobalt—tin bonds, in hydridocobalt complexes, 7, 5 Co-catalyst effects, in olefin polymerization, 4, 1111 (—)-Goccinine, via Alder-ene reactions, 10, 593 Co-condensation sites, in metal vapor synthesis technique,... 

Electric arcs, in metal vapor synthesis, 1, 224 Electric-field-induced second harmonic generation Group 8 metallocenes, 12, 109 for hyperpolarizability measurement, 12, 107 Electrochemical cell assembly, in cyclic voltammetry, 1, 283 Electrochemical irreversibility, in cyclic voltammetry, 1, 282 Electrochemical oxidation, arene chromium carbonyls, 5, 258 Electrochemical properties, polyferrocenylsilanes, 12, 332 Electrochemical reduction, bis-Cp Zr(III) and (IV) compounds, 4, 745 Electrochemical sensors biomolecule—ferrocene conjugates... 

Electron-beam heating, in metal vapor synthesis, 1, 232 Electron-beam vaporization, in metal vapor synthesis, 1, 224 Electron correlation, and computational chemistry, 1, 642 Electron counting, in transition metal complexes bridging ligands, 1, 14 examples, 1, 9 ligand electrons, 1, 5/... 

M-M bonded compounds, 4, 131 in monoolefin polymerization, 4, 141 Europium(II) complexes, alkyl compounds, 4, 4 Europocenes, characteristics, 4, 27 Evaporation rates, in metal vapor synthesis, 1, 225 Ewen s symmetry rules, for olefin polymerization stereocontrol, 4, 1023 Exchange reactions... 

Heteroalkenes, with iron, 6, 132 Heteroannulation, allylic benzylamines, 10, 156 Heteroarene chromium carbonyls, preparation and characteristics, 5, 260 Heteroarenes borylation, 10, 242 C—H functionalizations, 10, 127 as metal vapor synthesis milestone, 1, 237 with titanium, 4, 246 vanadium complexes, 5, 48 7]6-Heteroarenes, with platinum, 8, 664 Heteroaromatic compounds... 

Intrinsic reactivity, gas-phase study applications, 1, 803 Inverse crowns, preparation and reactions, 2, 109 Involatile liquids, in metal vapor synthesis, 1, 229 Involatile solids, in metal vapor synthesis, 1, 229 Iodide ligands... 

Lanthanide triflates, for allylic tin reactions, 9, 354 Laser beam heating, in metal vapor synthesis, 1, 224 Laser methods, in mechanistic studies, 1, 248 Laser photochemical vapor deposition, with organometallic complexes, 1, 259... 

Ligand introduction systems, in metal vapor synthesis, 1, 227... 

Liquid injection molding, for silicone rubbers, 3, 674—675 Liquid ligands, in metal vapor synthesis, 1, 229 Liquid-phase catalysis, supported, for green olefin hydroformylation, 12, 855 Lithiacarbaboranes, preparation, 3, 114 Lithiation, arene chromium tricarbonyls, 5, 236 Lithium aluminum amides, reactions, 3, 282 Lithium aluminum hydride, for alcohol reductions, 3, 279 Lithium borohydride, in hydroborations, 9, 158 Lithium gallium hydride, in reduction reactions, 9, 738 Lithium indium hydride, in carbonyl reductions, 9, 713—714... 

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