Stabilizer, role

The stabilizing role of other functional groups can also be described in resonance terms. Both electron-attracting groups such as carbonyl and cyano and electron-donating groups such as methoxy and dimethylamino have a stabilizing etfect on a radical intermediate at an adjacent carbon. The resonance structures which depict these interactions indicate delocalization of the unpaired electron onto the adjacent substituents ... 

Soil minerals play a stabilizing role in organic matter. The Al and Fe that complex and stabilize organic matter against microbial decomposition are released from soil minerals during soil formation. The supply rates apparently control the content of soil organic matter to a great extent. This is demonstrated by the relationship between pyrophosphate-extractable C and pyrophosphate-extractable Al plus Fe (Wada 1995). 

Other template cyclizations. In another Schiff-base template reaction, 1,3-diaminopropane monohydrochloride was reacted with biacetyl in methanol in the presence of Ni(n) to yield the nickel complex of the corresponding cyclic tetraimine - see [2.16] (Jackels et al., 1972). The success of the procedure illustrated is quite dependent on the reaction conditions employed. Attempts to isolate the metal-free macrocycle were unsuccessful - this once again emphasizes the stabilizing role of the metal... 

In connection to the data described earlier, one reasonable question arises Why does the stabilizing role of a nonaqueous solvent become significant for Cu salts and remain insignificant for Cu salts It was shown (Myagchenko et al. 1989) that Cu salts (and salts of Hg and Pd as well) exist in nonaqueous solutions as polynuclear compounds. Thus, CUCI2 forms lamellar lattices with chlorine chains as bridges between copper atoms. In contrast, CuCl does not form such chain structures. 

The SjN ion is unstable with respect to the formation of S N in solution and in the solid state under the influence of heat or pressure. It appears that large counter-ions, e.g. Ph As, PPN, play an essential stabilizing role by keeping the SjN" ions well separated in the crystal lattice. 

The presence of casein-polysaccharide interactions is commonly invoked to explain the mechanistic stabilizing role of food hydrocolloids in dairy colloids (Dickinson, 1998a). Thus, for example, under conditions where the casein micelles and K-carrageenan both carry a net negative... 

Both cations play a stabilizing role in various biological structures. Calcium ions are necessary to link the 24-subunit aggregates of the dioxygen carrier hemocyanin of Limulus polyphemus into the native 48-subunit molecule.121 The divalent character of Ca2+ probably allows it to crosslink... 

With an average radius of 4.33 A, the 51262 cavity is large enough to contain molecules smaller than 6.0 A in diameter. Ripmeester (Personal Communication, May 2, 1988) indicates that the 14-hedron is the preferred cage for almost all structure I hydrates, in which it plays the main stabilizing role. The oblate nature of the 51262 cage causes the shape of the guest molecule to play a role in cavity stability. 

Large reactivity differences are found in the temperature region above 473 K. It was stated previously that -in the case of trichlorosilane- the NH4C1 has a stabilizing role, allowing maximum capacity at temperatures below the sublimation point of NH4C1. It is only above this temperature that the actual differences in reactivity between B and Si preactivation are revealed. 

Myers (1960) recognized two kinds of stability, viz., inherent stability as a function of time, and induced stability as a function of stimuli. Induced kinetic stability necessitates the expenditure of work exceeding .12 Acceptance of a stabilization role for water has not been universal Jirgensons (1946) argued against it, enunciating instead the influence of particle shape and the mutual chemical affinity between atomic groups at the solid-liquid interface. 

Stabilizing Role of linear Polyamines as Pore Fillers During the Crystallization of Zeolite NU-10... 

Finally, the TEA+ and Na+ cations probably also play their complementary stabilizing role in the case of the FAU-polytype structure, as suggested by the chemical analysis (Table IV). The A1 framework negative charges are also nearly completely co-neutralized by both Na+ and TEA+ ions. This is not surprising if one considers that the FAU-polytype structure only differs from that of ZSM-20 by the close packing of the Faujasite truncated octahedra, that probably necessitate similar stabilization by Na+ and TEA+. 

During the first restructuration of the silicate or Si-rich aluminosilicate complexes prior to the zeolitic nucleation, the HM++ entities play a structure stabilizing role. By their particular linear shape, they favour the formation of channel systems. Simultaneously, they can also neutralize one AIO2- negative center of... 

Ressler et al. (2005) XAS Heteropolymolybdate, Nb substituted Phase stability role of promoter + + + Propene oxidation... 

---