Direct reactions between

Tetrabromosilane and tetraio do silane are produced by the direct reaction between sihcon and bromine at 500°C and sihcon and iodine at 600°C. There is no commercial production of these materials as of mid-1996. 

Derivatives such as borides, carbides, nitrides, and hydrides are best prepared by direct reaction between the elements. These metaHoid-type compounds, which often show variable composition, are colored and sometimes semiconducting. 

Covalent crosslinking. Acrylic polymers can be covalently crosslinked through direct reaction between functional monomers in the polymer itself or by the addition of a crosslinking reagent, which typically reacts with the functional groups or polymer backbone in the PSA. In general, acrylic polymers are very... 

Indium clusters have also recently been characterized, notably in intermetallic compounds. Thus, the Zintl phase, Rbzinj, (prepared by direct reaction between the two metals at I530°C) has layers of octahedral closo-lnf, clusters joined into sheets through exo bonds at four coplanar vertices. These four In atoms are therefore each bonded to five neighbouring In atoms at the comers of a square-based pyramid, whereas the remaining two (Irans) In atoms in the Ine cluster... 

Hydrogen cyanide, mp —13.3° bp 25.7°, is an extremely poisonous compound of very high dielectric constant (p. 55). It is miscible with H2O, EtOH and Et20. In aqueous solution it is an even weaker acid than HE, the dissociation constant Ka being 7.2 x 10 ° at 25°C. It was formerly produced industrially by acidifying NaCN or Ca(CN)2 but the most modem catalytic processes are based on direct reaction between... 

The problems of handling liquid ammonia are alleviated in this modification of the sodium acetylide generation procedure. Finely divided sodium is prepared in boiling toluene, the toluene is replaced by THF, and a direct reaction between sodium and acetylene is carried out. The resulting sodium acetylide is employed in ethynylation reactions as before. 

Compounds in which the —OH of an acid is transformed into —OR (such as —OCH3) are called esters. They can be prepared by the direct reaction between an alcohol and the acid. For example,... 

OCV conditions, by a newly formed SEI is expected to be a slow process. The SEI is necessary in PE systems in order to prevent the entry of solvated electrons to the electrolyte and to minimize the direct reaction between the lithium anode and the electrolyte. SEI-free Li/PE batteries are not practical. The SEI cannot be a pure polymer, but must consist of thermodynamically stable inorganic reduction products of... 

More realistically, the catalyst is generated in an independent reaction. Consider a reaction with two paths—a direct reaction between A and B and a product-catalyzed one, as shown ... 

The compounds AlYX are best prepared by direct reaction between the respective aluminum halide and chalcogenide in a sealed ampoule at 350°C. The reaction is complete after 2 weeks. In the case of the iodides, a mixture of A1 and I2 (molar ratio 3 10) is used instead of AII3. Other preparative methods, such as the reaction of an aluminum halide with Zn or Cd chalcogenide, or with the chalcogen itself, are applicable to the bromide and chloride only, and give poor yields (15-20%) (158, 159, 266, 327, 328). 

Yochelis, S. and Hodes, G. (2004). Nanocrystalline CdSe Formation by Direct Reaction between Cd Ions and Selenosulfate Solution. Chem. mater., 16,2740-2744. 

Yochelis S, Hodes G (2004) Nanocrystalhne CdSe formation by direct reaction between Cd ions and selenosulfate solution. Chem Mater 16 2740-2744... 

The occurrence of equilibrium (78) is confirmed by the incorporation of deuterium into molecular hydrogen from deuterated water. A brief study of the direct reaction between Ag and H2 indicates that both direct and catalysed reactions have the same velocity . ... 

Thus, Ip (inductor peroxide, primary oxide) derived from I d is converted by Ac d into the end-product, I(,x, which is inactive regarding the induction, i.e. coupling cannot turn into catalysis. Moreover, since there are several consecutive steps, and since the direct reaction between actor and acceptor is very slow, it follows that the value of Fj will not be changed by altering the ratio, ([Ac]/[I])o. However, in most cases studied the function Fj = /(Ac/I)q attains a limiting value, or at least varies therefore it has to be concluded that Manchot s concept cannot be maintained in its original form. 

At an Ni(110)-O surface exhibiting a (3 x 1) structure (0.3 ML of oxygen), benzene adsorption at room temperature induces a compression of the (3 x 1) added-row to a (2 x 1) structure. There was no evidence for a direct reaction between the surface oxygen and benzene, but on heating to 600 K the oxygen is removed (as CO) and the surface is clean, other than areas of a p(4 x 5)C carbidic phase.41... 

Analytical methods based upon oxidation/reduction reactions include oxidation/reduction titrimetry, potentiometry, coulometry, electrogravimetry and voltammetry. Faradaic oxidation/reduction equilibria are conveniently studied by measuring the potentials of electrochemical cells in which the two half-reactions making up the equilibrium are participants. Electrochemical cells, which are galvanic or electrolytic, reversible or irreversible, consist of two conductors called electrodes, each of which is immersed in an electrolyte solution. In most of the cells, the two electrodes are different and must be separated (by a salt bridge) to avoid direct reaction between the reactants. 

These observations were significant to our choice of reactants for probing CT at DNA-modified surfaces. In particular, an upright orientation of the DNA relative to the surface is required to probe DNA-mediated reactions otherwise a more direct reaction between an intercalating probe and the electrode might be possible. Consequently, reactants were selected such that a negative potential could be apphed, thereby initiating reduction of an intercalated redox probe distantly bound within DNA helix. Importantly, the... 

Finally we must address the difference in rate between the in situ alkylation of aniline at the end of nitrobenzene hydrogenation and that found for the direct reaction between aniline and 1-hexanol. One significant difference between the systems is the presence of water. Two moles of water are produced for every mole of nitrobenzene converted so the final water concentration will be in excess of the aniline concentration. In the direct reaction no water was present. Water is a known poison for a range of catalytic reactions [8-11] and we have shown in our own laboratories that water will reduce the rate of nitrobenzene hydrogenation [12], Therefore it is likely that the deactivation of the aniline reaction after nitrobenzene hydrogenation is due to inhibition by water. 

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