Paraffinic chains

Correlations have been found between certain absorption patterns in the infrared and the concentrations of aromatic and paraffinic carbons given by the ndA/method (see article 3.1.3.). The absorptions at 1600 cm due to vibrations of valence electrons in carbon-carbon bonds in aromatic rings and at 720 cm (see the spectrum in Figure 3.8) due to paraffinic chain deformations are directly related to the aromatic and paraffinic carbon concentrations, respectively. )... 

G. S. Hartley, A.queous Solutions of Paraffin-Chain Salts Hermann Cie, Paris, 1936, p. 45. 

Subtractive dye precursors (couplers) that could be immobilized in each of the silver containing layers were sought, so that dye formation in all layers could proceed simultaneously rather than successively. The first of these to be commercialized were in Agfacolor Neue and Ansco Color films, introduced soon after Kodachrome film. These reversal working films contained colorless couplers that were immobilized (ballasted) by the attachment of long paraffinic chains. The addition of sulfonic or carboxyUc acid groups provided the necessary hydrophilicity to make them dispersible as micelles in aqueous gelatin. 

The n-d-M correlation is an ASTM (D-3238) method that uses refractive index (n), density (d), average molecular weight (MW), and sulfur (S) to estimate the percentage of total carbon distribution in the aromatic ring structure (% C ), naphthenic ring structure (Cj,), and paraffin chains (% Cp). Both refractive index and density are either measured or estimated at 20°C (68°F). Appendix 4 shows formulas used to calculate carbon distribution. Note that the n-d-M method calculates, for example, the percent of carbon in the aromatic ring... 

Given that the presence of three alkoxy chains in the phenyl group produces such a dramatic change in the properties of the material to the point that columnar mesophases are formed at room temperature, the structure of the aryl isocyanide ligand has been further modified to introduce more paraffinic chains, and examples of metallodendrimers containing monodendrons with an isocyanide group in the focal point, and its gold compound 9, have been reported [26]. 

To investigate the extent of water penetration into the hydrocarbon region of lipid bilayers, pyrene linked to a carboxylic group via a paraffinic chain (e.g. 1-pyrenehexadecanoic acid) is best suited (L Heureux and Fragata, 1987). 

In the normal paraffin chains containing four or more carbons many different conformations are conceivable. In the solid, however, the Raman spectra show that all are in the fully extended conformation, so that there is a trans arrangement at all C-C bonds (11,18). In the liquid state a number of conformations coexist, with one of them being the extended-chain one provided the number of carbons is not too large. However, in cetane, with 16 carbons, the Raman lines arising from the extended form are no longer detectable in the liquid. 

Hartley, G.S. "Aqueous Solutions of Paraffin Chain Salts" Hermann et Cie Paris, 1936. 

Hartley GS. Aqueous solutions of paraffin-chain salts a study in micelle formation. Paris Hermann Cie 1936. 

Hartley GS (1936) Aqueous Solution of Paraffin Chain Salts, A Study of Micelle Formation. Herman and Co, Paris... 

Sodium cholate is insoluble in chloroform and in nonpolar solvents in general, but it is very soluble in alcohol and in water. Lecithin, on the contrary, is soluble in chloroform and only swells in water without dissolving in it. These differences in solubility are evidently related to the molecular structure and to the position of the hydrophilic groups in each of these molecules. The lecithin molecule has two important paraffinic chains and a group of hydrophilic functions (choline phosphate) localized at one end. In the presence of water, the lecithin molecules are oriented with their hydrophilic groups toward the water, and they hide their paraffinic chains inside a structure formed of two superposed layers of molecules. Conversely, in a nonpolar solvent the paraffinic chains are turned toward the solvent, while the polar groups are hidden inside the micelle. 

Thus, if two of these cholate molecules are fastened together by their hydrophilic face and held by three hydrogen bonds, only their lipophilic faces will appear laterally. Such a pair of molecules can therefore behave as an amphiphilic unit and be oriented with the carboxylic end groups toward water. The paraffinic portion of the pair can also be embedded between the paraffinic chains of other lipid molecules. 

The other experiment was performed by Isaksson (5) earlier. He extracted desiccated bile, using different solvents in succession. With chloroform, all of the lecithin was extracted but was accompanied by a large part of the bile salts. While bile salts by themselves are insoluble in chloroform, the extract thus obtained contains a proportion by weight of 2 parts of bile salt to 1 of lecithin—about one molecule of lecithin for three molecules of bile salt. Here, it is the lecithin, soluble in chloroform because of its paraffinic chains, which by association solubilizes the bile salt. It is interesting to inquire how these associations are achieved in both cases—i.e., how the molecules of bile salt are arranged and oriented in relation to the molecules of lecithin and to the polar or non-polar solvent. Let us examine first the state of the bile salt molecules in an aqueous phase. 

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