Influence of Solvent Type

Chen, D.Y., Jordan, E.H., and Gell, M. (2010) The solution precursor plasma spray coatings influence of solvent type. Plasma Chem. Plasma Process., 30 (1), 111-119. 

Influence of solvent type on the system constants of the solvation parameter model for a cyanopropylsiloxane-bonded silica sorbent in reversed-phase chromatography (r = 0 in all cases)... 

The influence of solvent type on the thermodynamics and kinetics of isobutylene and isoamylene hydration in the presence of the acidic catalyst, Amberlite-15, was studied [32]. Such solvents as dioxane, acetone, and nitromethane proved to be inert and provided lOOVo selectivity for tert-butyl alcohol formation at initial mole ratios of H20/isobutylene>4. Solvents containing an alcohol (butylcellulose, tetrahydro-furfuryl, isopropyl and cyclohexyl alcohols) or an acid (acetic acid) or acetate group... 

Influence of solvent type on solids content I viscosity relationship. Usually the binder is made as a 60-75% wt solution in a water miscible solvent. A low viscosity in this stage facilitates preparation and handling of the binder. After neutralisation the binder is diluted with water to form a micellar solution which consequently is pigmented. Unlike solvent-borne binders, water soluble types peak or plateau in their viscosity upon dilution with water. Both solvent type and solids content of the original solution influence the viscosity curve obtained on solution of a certain binder (Figure 3.4). The results from various experiments indicate that solvents like NBA, BE and isopropoxy ethanol often result in the most desirable (flat) dilution curves. 

Figure 9.8 Influence of solvent type on nanosphere size and on hydrodynamic effect. PCL = 14,000, 5 mg/mL measured after synthesis and quench (quench volumetric ratio = 0.33) in CIJM-dl.

The influence of solvent type on microstructure is illustrated in Table 5.2. 

Hoernschemeyer, D. (1974). Influence of solvent type on viscosity of concentrated polymer-solutions. Journal of Applied Polymer Science, 18( ), 61-75. 

The influence of solvents in glycosylation reactions has been observed and discussed extensively already (1,4,74). For instance, the participation of ethers, when anomeric leaving-groups are removed under SNl-type conditions, results [because of the reverse anomeric effect (75,76)] in the genera-... 

In order to select the optimal sample diluent that allows adequate detection at low level and good peak shape, investigate the influence of pH, type of organic solvent, percentage of organic solvent, addition of additives (cyclodextrin, surfactants, etc.), injection volume, different counter ions, etc. 

Figure .4 Influence of the type of solvent on the enantiomeric ratio for a thermodynamic activity of solvent equal to 0.3. For the reaction in the solid/gas bioreactor. apentan.2.oi = 0.05 and ame yi propionate = 0.1. For the reaction in liquid medium elpentan-2-ol = 0.04 (0.25 mol L ) and amethyl propionate...

Here, A denotes an add of type HA-, HA or BH+, and z and q denote the charge and the radius, respectively, of species i. The influence of permittivity on p/C, depends on the charges, radii and the charge locations of the add and its conjugate base. Table 3.3 shows the pKa values of some acids and add-base indicators in water, methanol and ethanol [3], The solvent effects on pK l are smaller for BH+-type adds than for HA- or HA-type acids. For the BH+-type acids, zA=l and zB=0 in Eq. (3.16), and the influence of solvent permittivity is expeded to be small. 

Of particular interest is the influence of solvents under SNl-type conditions, as has been well studied for ethers [1,2,8]. The participation of ethers results, owing to the reverse anomeric effect [28] under SNl-type conditions, in the generation of equatorial oxonium ions (see Scheme 6, S = OEtj), which again favor the formation of thermodynamically more stable axial a- products [see Sec. 11I.B, Eqs. (6), (11), (16)]. 

Naumov S, Beckert D (2002) Reply to the Comment on A Fourier transform EPR study of uracil and thymine radical anions in aqueous solution)/ by DM Close. Phys Chem Chem Phys 4 45 Naumov S, Barthel A, Reinhold J, Dietz F, Geimer J, Beckert D (2000) Calculation of spin densities of radicals of pyrimidine-type bases by density functional theory. Influence of solvent and comparison with EPR results. Phys Chem Chem Phys 2 4207-4211 Naumov S, Hildenbrand K, von Sonntag C (2001) Tautomers of the N-centered radical generated by reaction of SO4 - with N(1)substituted cytosines in aqueous solution. Calculation of isotropic hyperfine coupling constants by a density functional method. J Chem Soc Perkin Trans 2 1648-1653... 

Current efforts in quantum-chemical modeling of the influence of solvents may be divided into two distinct approaches. The first, the supermolecular approximation, involves the explicit consideration of solvent molecules in quantum-chemical calculations. Another possibility for simulating solvent influence is to replace the explicit solvent molecules with a continuous medium having a bulk dielectric constant. Models of this type are usually referred to as polarized continuum models (PCMs). 

Solvolysis rates of t-butyl-dimethylsulfonium salts decrease with increasing solvent polarity [710]. Analogously, the rate of solvolysis of triethyloxonium salts in ethanol/water mixtures decreases with increasing water content [490]. Solvolysis rates of A-t-alkylpyridinium salts such as 1-(1-methyl-l-phenylethyl)pyridinium perchlorate are almost independent of solvent polarity, whereas A-s ec-alkylpyridinium salts exhibit small decreases in rate with increasing solvent polarity [710]. The non-creation of charge in the activation process of these type (b) reactions much reduces the influence of solvent polarity on rate cf. Table 5-4. 

In our earlier work [85] the literature data were analyzed under the assumption that the influence of solvents on the standard rate constant of the electrode reaction may be expressed by the Bronsted-type relation... 

The most common approach to the study of discrete variations in the reaction space is to consider one type of variation at a time. For example The scope of a reaction with regard to substrate variation is often studied by means of a series of test substrates while maintaining the reagent(s) and solvent fixed the influence of solvent variation is studied with one test substrate and with a given reagent, etc. 

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