INDEX Amine systems

The exact value of the index n is not critical for our purposes and the choice of n = 2 fits the data well. Note the very difference activation energy compared to the high temperature expression (Equation A). Certainly this discrepancy is beyond any experimental error, indicating the presence of a different curing mechanism at these temperatures. The value of = A6A0 K compares well with values quoted by others for epo -amine systems studied by isothermal gel time measurements at low temperatures... 

On the basis of data obtained the possibility of substrates distribution and their D-values prediction using the regressions which consider the hydrophobicity and stmcture of amines was investigated. The hydrophobicity of amines was estimated by the distribution coefficient value in the water-octanole system (Ig P). The molecular structure of aromatic amines was characterized by the first-order molecular connectivity indexes ( x)- H was shown the independent and cooperative influence of the Ig P and parameters of amines on their distribution. Evidently, this fact demonstrates the host-guest phenomenon which is inherent to the organized media. The obtained in the research data were used for optimization of the conditions of micellar-extraction preconcentrating of metal ions with amines into the NS-rich phase with the following determination by atomic-absorption method. 

Common names of the compounds arc used throughout this volume. Preparations appear in the alphabetical order of common names of the compound or names of the synthetic procedures. The Chemical Abstracts indexing name for each title compound, if it differs from the common name, is given as a subtitle. Because of the major shift to new systematic nomenclature adopted by Chemical Abstracts in 1972, many common names used in the text are immediately followed by the bracketed, new names. Whenever two names are concurrently in use, the correct Chemical Abstracts name is adopted. The prefix n- is deleted from w-alkanes and w-alkyls. In the case of amines, both the common and systematic names are used, depending on which one the Editor-in-Chief feels is more appropriate. All reported dimensions are now expressed in Systeme International units. 

An appendix systematically lists references to reactions of dialkylalkoxy-malonates with amines, including not only the common aliphatic and aromatic amines, but also a very wide variety of heterocyclic amines classified according to ring system. The appendix also provides systematic references to the different ring systems obtained by ring closure of the dialkylaminomethylenemalonates. The appendix should be used in conjunction with the subject index a separate subject index is provided for this monograph volume. 

Morrall2 used a HPLC system with two columns. The first column was loaded with the controlled pore glass (CPG) to be modified. The second column was used for separation of the reaction effluents. This column was coupled to a refractive index detector, allowing for quantitative detection of the effluents. The reaction was initiated by injecting an APTS/toluene mixture and stopped by injection of pure toluene. With this so-called stop-flow mechanism reaction times down to 18 seconds could be used. From these analyses it became evident that upon mixing of the aminosilane with the silica, a very rapid physisorption occurs. The initial adsorption of the APTS (from toluene solution on dried CPG) occurred before the 18 second minimum time delay of the stop-flow apparatus. For non-aminated silanes the adsorption proved to be much slower. This study also revealed the pivotal role of surface water in the modification of siliceous surfaces with alkoxysilanes, as discussed in the previous chapter. 

The relationships of oxidation potential to radical reactivity index Sr and nucleophilic reactivity index Sn illustrated in Figure 4 are very similar to those with antioxidation and antiozonization, where the maximum values were observed at 0.4 and 0.25 volt. Therefore, antioxidation seems to proceed by a radical mechanism in contrast to the nucleophilic type of antiozonization. Indeed, the antioxidation effect of amines toward NR, SBR, BR, and HR is well correlated with radical reactivity as shown in Figures 5-8. The protection of SBR solution by amines from oxidative degradation and the termination of chain reaction in the oxygen-Tetralin system are also shown as functions of Sr in Figures 9 and 10. 

Since both molar volume and refractive index are influenced by the actual molecular species present in a solution, molar refraction has some potential value for studying association equilibria. Giles and co-workers (65-68) correlated the method with dielectric constant measurements, and have been the most active users of refractive index for studying compound formation. Reference 68 reviews earlier work (which is sketchy) and lists about forty systems (mostly oxygen containing compounds) that were studied. References 65-67 deal with amide, amine, and azo compounds, plus esters and additional work on alcohols, aldehydes, ketones, and carbohydrates. The method is simple the refractive index of a series of mixtures of varying composition but constant concentration in a solvent is measured. Compound formation is shown by a change in the slope of the n vs. mole fraction plot, such as in Fig. 2-15. 

Contents Theory of Electrons in Polar Fluids. Metal-Ammonia Solutions The Dilute Region. Metal Solutions in Amines and Ethers. Ultrafast Optical Processes. Metal-Ammonia Solutions Transition Range. The Electronic Structures of Disordered Materials. Concentrated M-NH3 Solutions A Review. Strange Magnetic Behavior and Phase Relations of Metal-Ammonia Compounds. Metallic Vapors. Mobility Studies of Excess Electrons in Nonpolar Hydrocarbons. Optical Absorption Spectrum of the Solvated Electron in Ethers and Binary Liquid Systems. Subject Index. Color Plates. 

One other possible index for the resonance interaction in these systems is the chemical shift of the enamine, whether as such or relative to that of the corresponding saturated amine . It is a measure of the activation energy for twist about the C—NR R bond, but it is less generally applicable than the former index based on the ionization potentials, even though it can be measured in the condensed phase where the basicity is to be determined. 

Vanadium(IV) oxy(acetylacetonate) is a blue to blue-green compound, crystallizing in the monoclinic system with refractive indexes of a, 1.520 0, 1.676 y, 1.739.7 The compound was originally believed to be a 1-hydrate but is now known to be anhydrous. It forms addition compounds with pyridine, methylamine, and other amines.8 Vanadium(IV) oxy(acetylacetonate) decomposes at elevated temperatures and has no definite melting point. The compound is soluble in ethanol, benzene, chloroform, and acetylacetone but is only moderately soluble in acetone or ethyl ether. 

Initial experiments were undertaken with morpholine, dicyclohexylamine and dibutylamine terminated GPTA systems as well as the diethylamine sample which has already been investigated in previous work (14,15). The effect of Microscal irradiation on the increase in hydroxyl index of these amine acrylates is illustrated by the data in Table I. This shows that the nature of the terminal amine functionality has a marked effect on the hydroxyl index profile during irradiation. The following order of increasing hydroxyl index was observed relative to amine functionality ... 

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