Two Cases of Special Interest

SOLVOLYSIS. A generalized conception of the relation between a solvent and a solute (i.e., a relation between two components of a single-phase homogeneous system) whereby new compounds arc produced, In most instances, the solvent molecule donates a proton to. or accepts a proton from a molecule of solute, or both, forming one or more different molecules. A particular case of special interest occurs when water is used as solvent, m which case die interaction between solute and solvent is called hydrolysis. 

A case of special interest is that of the transport of divalent ions such as calcium versus monovalent ones. The lipophilic carrier 86, containing a single cation receptor site and two ionizable carboxylic acid groups, was found to transport selectively Ca2+ in the dicarboxylate form and K+ when monoionized, thus allowing pH control of the process. This striking change in transport features as a function of pH involves pH regulation of Ca2+-K+ selectivity in a competitive (Ca2+, K+) symport... 

The production of OH described here has two features of special interest, being the only case where the vibrational energy is supplied by the electronic energy of an atom and where the proportion of energy appearing as vibration has been estimated. It appears that at least 30% of the OH radicals produced are vibrationally excited and this approximate figure is obtained on the basis that the relative proportions observed do not represent an appreciable relaxation from a state of higher excitation. This appears to be a reasonable assumption in this case, since Reaction 10 may well be faster than relaxation. 

CO and O both have two possible adsorption sites on RuO2(110), so DFT calculations were used to determine the adsorption energies for these sites and activation energies for diffusion between them. All diffusion processes were assumed to have a prefactor of 1012 s This assumption could in principle be avoided by computing the vibrational frequencies needed to derive these prefactors within harmonic TST, but this is unlikely to be necessary unless surface diffusion is found in cases of special interest to be a rate-limiting factor. 

MM3/MM4 are intended to deal with aromatic rings that are bent out of planarity, and they appear to do so to within the limitations of the experimental data available. These calculations have been extended to quite large molecules (Ceo and above), and the MM4 values for heats of formation are probably the best currently available for compounds of this size. We will here briefly discuss two specific cases of special interest, [18]annulene and fullerene. 

When any two condensed phases are in contact, it is common to talk about the interfacial tension of the system. A case of special interest involves two polymers in contact, Table 12.2 (7). Numerically the values of the interfacial... 

The most interesting case of fractionation was observed on the example of poly r-butyl thiirane [12]. Using selective solubility in benzene and chloroform, two fractions of special interest were isolated (Table IX) Fraction (I) optically active and having a melting point of 157° and fraction (III) of low optical activity (an improvement in fractionation furnished a completely optically inactive product) and with a melting point of 203°. 

In many cases, addition or removal of water proceeds sufficiently slowly that some of the physical properties of unstable species (such as hydrated neutral quinazoline or anhydrous 2-hydroxypteridine) can be observed. In these cases, reaction kinetics can also be examined. Addition of water to pteridine is of special interest in relation to studies of the formation and hydrolysis of Schiflf bases. The reaction proceeds in two reversible stages, 3 4 5 ... 

Trifluoropropene is a compound of special interest in this series. Some transformations of the intermediate telomer radicals had been observed in this case, which prompted to study this reaction in more details. In addition to telomers C6H5CH2(CH2CHCp3)nBr (T Br, n = 1,2), the authors have found compound PhCH=CHCH(CF3)CH2CH2Cp3 and explained its formation by rearrangement of the intermediate radical with two monomer units followed by easy... 

Another curvilinear coordinate system of importance in two-centre problems, such as the diatomic molecule, derives from the more general system of confo-cal elliptical coordinates. The general discussion as represented, for instance by Margenau and Murphy [5], will not be repeated here. Of special interest is the case of prolate spheroidal coordinates. In this system each point lies at the intersection of an ellipsoid, a hyperboloid and and a cylinder, such that... 

The problem of the immunogenic nature of many human recombinant DNA proteins, and the potential to generate antibodies to a normal human protein, is of special interest to the immunotoxicologist. For example, 3 of 16 patients administered the rDNA-derived interferon-a (clone A) developed antibodies of the IgG class that were undetectable prior to or during therapy (Gutterman et al., 1982). These antibodies were capable of in vitro neutralization of interferon activity, although in vivo neutralization of interferon has not been documented. Since there are several different subtypes of interferon-a s, some contain epitopes not present on their own interferon subtype. Similarly, two patients treated with interferon-/ for many months developed high-titered antibody, which in one case was correlated with an inability of the patient s fibroblasts to produce interferon (Vallbracht et al., 1982). 

A very popular recent research topic has been the functionalization of curved graphenes, in fullerenes and especially in CNTs [47-50], Not only surface functional groups but also organic compounds and biomaterials have been used [49,51] in the latter case, a more appropriate term is grafting, and the SCI identified 26 papers explicitly devoted to this procedure for nanotubes, all of them published in the last 3 years. The following two issues—one more fundamental and the other more utilitarian— merit our attention here (i) Are only the graphene terminations (edges) functionalized, or is sidewall functionalization feasible as well (ii) Which procedures are of special interest for electrochemical applications ... 

If cyclopentadienyliron dicarbonyl halides are allowed to react with themselves in the presence of Lewis acids, cations are formed in which the new substituent is the cyclopentadienyliron dicarbonyl halide itself, for example, [CjH6Fe(CO)i-X-(CO)2-FeC8H8]+ (X = Cl, Br, I). All three cations can be prepared best by treatment of the corresponding halides with boron trifluoride diethyl etherate all are isolated as tetrafluoro-borates.18 The bromine complex can also be obtained by a more complicated procedure by the reaction between C8H8Fe-(CO)2Br and AlBr3 in liquid sulfur dioxide 16 the iodine cation can be isolated from a melt of cyclopentadienyliron dicarbonyl iodide and aluminum chloride.17 In the latter two cases the hexafluorophosphate salts can be obtained. These binuclear cations are of special interest, because they are cleaved by electron donors,16-17 e.g., aniline, pyridine, benzonitrile, acetonitrile, acrylonitrile, with the formation of the corresponding [C8H8Fe(CO)2L]+ cations and the parent halide. Equations for preparation of the tetrafluoroborate are ... 

Three examples are popular here. The first two start with flash photolysis, where an intense flash irradiates the whole cell at t = 0, instantly producing an electrochemically active species that decays chemically in time, either by a first-order reaction, or a second-order reaction. The labile substance is assumed to be formed uniformly in the cell space with a bulk concentration of c. These are cases where the concentration at the outer boundary is not constant, falling with time. The third case, the catalytic or EC7 system (see [73,74]), is of special interest because of the reaction layer it gives rise to. 

The case U = 0 is of special interest. In such a case, making one bipolaron from two polarons does not cost energy. The maximum spin concentration is i, which means that 50% of the boxes possess unpaired spins. This result can be explained as follows. Since (1) at the maximum spin concentration one has q = 1, and (2) placing one or two balls in the box is equivalent, there are four equiprobable cases (1) neutral site (no ball), (2) polaron up, (3) polaron down, and (4) bipolaron (two balls). Two among four of these states are magnetic, which gives for the spin concentration. The room-temperature data for polypyrrole and poly aniline can almost be fitted with U 0, which means that in these compounds polarons and bipolarons would be degenerate. 

To synthesize water-soluble or swellable copolymers, inverse heterophase polymerization processes are of special interest. The inverse macroemulsion polymerization is only reported for the copolymerization of two hydrophilic monomers. Hernandez-Barajas and Hunkeler [62] investigated the copolymerization of AAm with quaternary ammonium cationic monomers in the presence of block copoly-meric surfactants by batch and semi-batch inverse emulsion copolymerization. Glukhikh et al. [63] reported the copolymerization of AAm and methacrylic acid using an inverse emulsion system. Amphiphilic copolymers from inverse systems are also successfully obtained in microemulsion polymerization. For example, Vaskova et al. [64-66] copolymerized the hydrophilic AAm with more hydrophobic methyl methacrylate (MMA) or styrene in a water-in-oil microemulsion initiated by radical initiators with different solubilities in water. However, not only copolymer, but also homopolymer was formed. The total conversion of MMA was rather limited (<10%) and the composition of the copolymer was almost independent of the comonomer ratio. This was probably due to a constant molar ratio of the monomers in the water phase or at the interface as the possible locus of polymerization. Also, in the case of styrene copolymerizing with AAm, the molar fraction of AAm in homopolymer compared to copolymer is about 45-55 wt% [67], which is still too high for a meaningful technical application. 

The other interfacial tensions appearing in the Young equation, cTs and asi, are not accessible to measurement as yet. The former is of special interest, because it is the solid surface characteristic of interest. In addition, the YCA can be measured only in very few cases that involve solid surfaces, which are close to being ideal. Thus, even if the values of 9y and ct/ are known, Eq. (1) stiU contains two unknowns. In order to elucidate Uj from the Young equation, or predict wetting behavior on a predefined solid surface, the value of asi must be known. 

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