Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Coupling index

On the basis of the above scheme the value of the coupling index is... [Pg.513]

So far possible processes leading to the occurrence of coupled reactions have been indicated. However, with regard to the nature of the reactive intermediates, it has been mentioned only that these, formed either from the actor or from the inductor, are more active than the actor itself. In the case of simpler systems, as was pointed out by Luther and Rutter , the knowledge of the coupling index makes it possible to estimate the quality (oxidation number) of the coupling intermediate. If a and co are the oxidation numbers of the actor before and after the reaction, and x is the oxidation number of the coupling intermediate, and furthermore, if only the acceptor reacts with the intermediate then... [Pg.515]

Generally, when two phases are in electronic equilibrium, eoifa — fa) = Hi — ji 2- In our case, the wire I is in equilibrium with the metal M, the latter is in equilibrium with the redox couple, and the platinum electrode II is in equilibrium with the reference couple (index ref ). [Pg.19]

Matrix elements of H between separated pair functions which differ in the spin coupling index k are given by... [Pg.108]

A further method for the synthesis of the title compounds with only hydrogen as byproduct is the base-catalyzed dehydrogenative coupling (index D) of ammonia and tris(hydridosilylethyl)boranes, B[C2H4Si(R)H2]3 (R = H, CH3). Initially, the strong base, e.g. n-butyl lithium, deprotonates ammonia. The highly nucleophilic amide replaces a silicon-bonded hydride to form a silylamine and lithium hydride, which then deprotonates ammonia, resuming the catalytic cycle. Under the conditions used, silylamines are not stable and by elimination of ammonia, polysilazane frameworks form. In addition, compounds B[C2l-L Si(R)H2]3 can be obtained from vinylsilanes, H2C=CHSi(R)H2 (R - H, CH3), and borane dimethylsulfide. [Pg.89]

In summary, coupled reactions can be used in some cases to bring about induced reactions that, taken alone, would be thermodynamically impossible. In many cases, determination of the coupling index affords important clues to the mechanisms of complex redox reactions. [Pg.303]

The basic condition of the Standard application - the availability of stable coupled probabilistic or the multiple probabilistic relations between then controlled quality indexes and magnetic characteristics of steel. All the probabilistic estimates, used in the Standard, are applied at confidence level not less than 0,95. General requirements to the means of control and procedure of its performance are also stipulated. Engineers of standard development endeavoured take into consideration the existed practice of technical control performance and test at the enterprises that is why the preparation of object control for the performance of nondestructive test can be done during the process of ordinary acceptance test. It is suggested that every enterprise is operated in correspondence with direct and non-destructive tests, obtained exactly at it, for detailed process chart and definite product type, however the tests have long since been performed after development of the Standard displayed that process gives way to unification. [Pg.25]

Attenuated total reflection, on which atr—ftir is based, occurs when the rarer medium is absorbing and is characterized by a complex refractive index (40). The absorbing characteristics of this medium allow coupling to the evanescent field such that this field is attenuated to an extent dependent on k. The critical angle in the case of attenuated total reflection loses its meaning, but internal reflection still occurs. Thus, if the internally reflected beam is monitored, its intensity will reflect the loss associated with the internal reflection process at the interface with an absorbing medium. [Pg.287]

The index of refraction of PVB (1.48) is close enough to glass (1.520) to couple the two glass pHes with a reflectance loss of only 0.02% ... [Pg.524]

The Colour Index (up to June 1991) Hsts 21 direct violets with disclosed chemical constitutions. Commercially important are Cl Direct Violet 9 [6227-14-1] (79) (Cl 27885) (sulfanihc acid coupled to cresidiue followed by alkaline coupling to V-phenyl J-acid) and Cl Direct Violet 66 [6798-03-4] (80) (Cl 29120) (a copper complex of 2-arniao-l-phenol-4-sulfonarnide (2 mol) coupled to 6,6 -imiQobis-l-naphthol-3-sulfonic acid). [Pg.443]

This polymer has a good strength for a flexible silicone polymer coupled with the good heat resistance which may be expected from its components, together with an outstanding value for the limiting oxygen index of 48. [Pg.840]

Figure 14.17 Schematic diagram of the on-line coupled LC-GC system VI, valve foi switcliing the LC column outlet to the GC injector V2, valve for switching the LC column to back-flush mode V3, LC injection valve RI, refractive index monitor detector UV, ulti avio-let monitor detector FID, flame-ionization detector. Figure 14.17 Schematic diagram of the on-line coupled LC-GC system VI, valve foi switcliing the LC column outlet to the GC injector V2, valve for switching the LC column to back-flush mode V3, LC injection valve RI, refractive index monitor detector UV, ulti avio-let monitor detector FID, flame-ionization detector.
We have studied the vibrational properties of Au adatoms on the low-index faces of copper. From the position of new phonon modes, which are due to the presence of the adatom, it comes out that the gold adatom is weakly coupled with the atoms of Cu(l 11) for the directions parallel to the surface and tightly bound with those of Cu(lOO). These modes are found in lower frequencies than those of the Cu adatom. The temperature dependence of MSD s and relaxed positions of the Au adatom along the normal to the surface direction, reveal that this atom is more tightly bound with the (111) face and less with the (110) face. [Pg.155]

Silane radical atom transfer (SRAA) was demonstrated as an efficient, metal-free method to generate polystyrene of controllable molecular weight and low polydispersity index values. (TMSlsSi radicals were generated in situ by reaction of (TMSlsSiH with thermally generated f-BuO radicals as depicted in Scheme 14. (TMSlsSi radicals in the presence of polystyrene bromide (PS -Br), effectively abstract the bromine from the chain terminus and generate macroradicals that undergo coupling reactions (Reaction 70). [Pg.152]


See other pages where Coupling index is mentioned: [Pg.513]    [Pg.100]    [Pg.89]    [Pg.513]    [Pg.100]    [Pg.89]    [Pg.1189]    [Pg.2222]    [Pg.2274]    [Pg.485]    [Pg.530]    [Pg.288]    [Pg.330]    [Pg.330]    [Pg.133]    [Pg.134]    [Pg.16]    [Pg.218]    [Pg.60]    [Pg.335]    [Pg.30]    [Pg.265]    [Pg.27]    [Pg.272]    [Pg.151]    [Pg.463]    [Pg.162]    [Pg.408]    [Pg.488]    [Pg.540]    [Pg.377]    [Pg.493]    [Pg.107]    [Pg.103]    [Pg.292]    [Pg.12]    [Pg.382]    [Pg.89]   
See also in sourсe #XX -- [ Pg.513 , Pg.515 ]




SEARCH



Coupling constants 296 INDEX

INDEX coupled-cluster approaches

INDEX exchange coupled

INDEX vector coupling

Subject index HH coupling constants

Subject index NH coupling constants

© 2024 chempedia.info