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Stability equation

The electrophilic character of sulfur dioxide does not only enable addition to reactive nucleophiles, but also to electrons forming sulfur dioxide radical anions which possess the requirements of a captodative" stabilization (equation 83). This electron transfer occurs electrochemically or chemically under Leuckart-Wallach conditions (formic acid/tertiary amine - , by reduction of sulfur dioxide with l-benzyl-1,4-dihydronicotinamide or with Rongalite The radical anion behaves as an efficient nucleophile and affords the generation of sulfones with alkyl halides " and Michael-acceptor olefins (equations 84 and 85). [Pg.216]

Then the basic stabilization equation for each cycle atom will take into account the average energy of hybridized cycle atoms ... [Pg.209]

Hydroxylating 3-phenylisoxazoline is enthalpicly the same as for cyclopentane, with an added 39 kJmol for anomeric stabilization (equation 46) °. [Pg.76]

The [l,2,3]triazolo[4,5-solid state, fragmented in solution and yielded the 1,2,3-triazoles 123 and a variety of NFS compounds. Even at —30 °C in NMR solvents the bicycles lacked stability (Equation 3) <1997CC2149>. [Pg.227]

If redissociation into reactants is faster than stabilization, equations (3.15) and (3.16) simplify into a product of k,/k, and either kr or kcoll. Under these conditions, to obtain a theory for a total association rate coefficient, one must calculate both k,/k i and kr or kco . Three levels of theory have been proposed to calculate k, /k, . In the simplest theory, one assumes (Herbst 1980 a) that k, /k 3 is given by its thermal equilibrium value. In the next most complicated theory, the thermal equilibrium value is modified to incorporate some of the details of the collision. This approach, which has been called the modified thermal or quasi-thermal treatment, is primarily associated with Bates (1979, 1983 see also Herbst 1980 b). Finally, a theory which takes conservation of angular momentum rigorously into account and is capable of treating reactants in specific quantum states has been proposed. This approach, called the phase space theory, is associated mainly with Bowers and co-workers... [Pg.147]

Michael addition of tin enolates to a,/3-unsaturated esters is accomplished in the presence of catalytic amount of Bu4NBr. Other typical system using lithium enolates or silyl enolates with catalysts (Lewis acid or Bu4NF) fails to give the Michael products. An ab initio calculation reveals that higher reactivity is caused by high coordination of the tin enolate and the keto enol tautomerization for Michael adducts contributes to thermodynamical stabilization (Equation (77)).231 232... [Pg.363]

N-Protonation of 1-azaallyl anions506, prepared by deprotonation of azomethines, leads almost quantitatively and stereospecifically to secondary enamines of considerable stability (equation 31). [Pg.493]

The governing equations are given in the next section. The mean flow, whose stability will be studied, is given in the section 6.3. The stability equations and related numerical methods for CMM is given in section 6.4. The results and discussion follow in section 6.5. The chapter closes with some comments and outlook in section 6.6. [Pg.199]

Here the stability equations for two dimensional plane flows have been derived, by starting from the non-dimensional Eqns. (6.2.4) -(6.2.6) given... [Pg.202]

The quantities with the over-bar are related to the mean flow solutions of the previous section, via the appropriate transformations. The stability equations are obtained by making the additional parallel flow assumption, U = U y), V = 0 and T = T y) so that a normal mode spatial instability analysis is possible by looking for a solution of the linearized equations of the following form ... [Pg.203]

Mean flow is obtained using the similarity co-ordinate p, while the stability equations are solved using the independent variable, y = y /5, where y is the dimensional height over the plate and S is the displacement thickness of the boundary layer. In terms of rj, the displacement thickness is given... [Pg.211]

Alkylbenzo[ ]furans were oxidized by chloroperoxidase from Caldariomycesfumago to their /ra r-2,3-diols as major products, and these were all fully characterized because of their stability (Equation 78) <2001T8581>. [Pg.443]

The synthesis of sodium trifluoropropenylbenzenesulfonate, (Equation 12) uses the diazo compound obtained from aniline-2-sulfonic acid and isopropyl nitrite in isopropanol for the oxidative addition to palladium(0)/dba, in the absence of phosphine ligands, with NaOAc as buifer. The substrate itself contributes to palladium stabilization (Equation 16). [Pg.176]

The reaction between Ta(NMe2)s and silanes yielded an unusual dihydride imine complex (17) through /3-H abstraction between amide ligands (equation 10)." The first Cp-ffee silyl (18) and disilyl Ta derivatives have been reported. They are potential precursors to Ta-N-Si ternary materials. Unusual oxidation products such as (19) could be stabilized (equation 11). ... [Pg.2939]

S.A. Orszag, Accurate solution of the Orr-Sommerfeld stability equation, J. Fluid Mech., 50 (1971) 689-703. [Pg.234]

The linear system obtained by the discretization of equations (5)-(6) can also be solved directly. Notice that this system is symmetric but not definite positive. A three-field version of the Stokes problem was considered in [17] and a second inf-sup condition is then necessary to obtain stability (equation (30) of 6.4). [Pg.242]

The spun fibers were cross-linked (cured) by air oxidation and pyrolyzed to give silicon-carbide-type fibers. Yajima et al. (7) reported further that heteroatoms such as titanium could be incorporated into the polymers and ceramic fibers to enhance their stability (equation 3). [Pg.594]

A diradical pathway was suggested by Christl and coworkers for 95 (equation 124). This is supported by the lower activation energy for this compound as compared with its analog, 7, whose diradical intermediate is a less potent radical stabilizer (equation 125). [Pg.1172]

The aromatization of bridged adducts (149) is known. For example, tetrachloro-phthalic anhydride (162) is formed in moderate yield from acetal 159 and halocyclopro-penes 160. In all probability the initial adduct spontaneously cleaves to zwitterion 161 in which the charges are stabilized (equation 59). Although its subsequent conversion into product is not fully understood, 161 has the appropriate skeleton for transformation into 162. [Pg.1267]

All time-dependence and (sensitive) dependence on the external control parameters is contained in the function Q, which is often called ji -correlator and obeys the non-linear stability equation [43, 45, 80]... [Pg.90]

The described universal scenario of shear-molten glass and shear-thinnig fluid makes up the core of the MCT-ITT predictions derived from (11-14). Their consequences for the nonlinear rheology will be discussed in more detail in the following sections, while the MCT results for the linear viscoelasticity were reviewed in Sect. 3. Yet, the anisotropy of the equations has up to now prevented more complete solutions of the MCT-ITT equations of Sect. 2. Therefore, simplified MCT-ITT equations become important, which can be analysed in more detail and recover the central stability equations (20, 22). The two most important ones will be reviewed next, before the theoretical picture is tested in comparison with experimental and simulations data. [Pg.93]

The melting of the glassy structure during the yield process of (28) can be explicitly evaluated in the schematic F P -model at e = 0. The yield master function does not depend on y, and while its form is model-dependent, its initial decay follows from the universal stability equation (22). Figure 16 shows numerical results, which can be well approximated by an exponential function. [Pg.103]


See other pages where Stability equation is mentioned: [Pg.199]    [Pg.216]    [Pg.28]    [Pg.70]    [Pg.175]    [Pg.213]    [Pg.10]    [Pg.64]    [Pg.50]    [Pg.420]    [Pg.515]    [Pg.1765]    [Pg.318]    [Pg.318]    [Pg.164]    [Pg.984]    [Pg.50]    [Pg.26]    [Pg.114]    [Pg.198]    [Pg.202]    [Pg.204]    [Pg.212]    [Pg.214]    [Pg.515]    [Pg.197]    [Pg.100]   
See also in sourсe #XX -- [ Pg.31 ]




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