Betaines values

In number of labs, the NIR is a rapid, non-destructive test. It is used (everywhere) for water determination. For the petroleum industry, it is routinely used for octane and betaine values, to determine levels of additives, and as a test for unsaturation. The polymer companies, in addition to identification, use NIR for molecular weight, cross-linking, iodine value (unsaturation) block copolymer ratios, and numerous... 

The desugarization by-product is normally sold as a low value molasses. Pulse method systems also produce a relatively high value betaine-rich (at least 50% on soHds) fraction. The concentrated betaine-rich by-product is used as a custom animal feed, whose European markets are well estabUshed and may provide a future opportunity in the U.S. feed industry. Beet sugar molasses contains from 3 to 6% betaine, by weight, about three-quarters of which may be recoverable as a potential by-product ( 40 50% purity). 

Foam regulators such as amine oxides, alkanolamides, and betaines are present in products where high foam value is functionally or estheticaHy desirable, mainly hand-dishwashing Hquids and shampoos. In automatic dishwashing products, on the other hand, copious foam volumes interfere with the efficiency of the mechanical rotors during operation. In this type of product, a foam depressant is often present. 

Azolecarboxylic acids can be quite strongly acidic. Thus l,2,5-thiadiazole-3,4-dicar-boxylic acid has first and second values of 1.6 and 4.1, respectively <68AHC(9)107). The acidic strengths of the oxazolecarboxylic acids are in the order 2>5>4, in agreement with the electron distribution within the oxazole ring <74AHC( 17)99). Azolecarboxylic acids are amino acids and can exist partly in the zwitterionic, or betaine, form e.g. 394). 

If a sample contains groups that can take up or lose a proton, (N//, COO//), then one must expect the pH and the concentration to affect the chemical shift when the experiment is carried out in an acidic or alkaline medium to facilitate dissolution. The pH may affect the chemical shift of more distant, nonpolar groups, as shown by the amino acid alanine (38) in neutral (betaine form 38a) or alkaline solution (anion 38b). The dependence of shift on pH follows the path of titration curves it is possible to read off the pK value of the equilibrium from the point of inflection... 

Reactions between A -(l-chloroalkyl)pyridinium chlorides 33 and amino acids in organic solvents have a low synthetic value because of the low solubility of the amine partner. A special protocol has been designed and tested in order to circumvent this drawback. Soon after the preparation of the salt, an aqueous solution of the amino acid was introduced in the reaction medium and the two-phase system obtained was heated under reflux for several hours. However, this was not too successful because sulfur dioxide, evolved during the preparation of the salt, was converted into sulfite that acted as an 5-nucleophile. As a result, A -(l-sulfonatoalkyl)pyridinium betaines such as 53 were obtained (Section IV,B,3) (97BSB383). To avoid the formation of such betaines, the salts 33 were isolated and reacted with an aqueous solution of L-cysteine (80) to afford thiazolidine-4-carboxylic acids hydrochlorides 81 (60-80% yields). 

In general, the A -methyl derivative of a given compound absorbs at longer wavelengths than the O-methyl derivative. The intensity of a band which appears in aqueous solutions beyond the maximum absorption in alcohol and which is due to the absorption of the betainic species alone, is a measure of the tautomeric equilibrium. The pA"a value of the 2-methyl-hydroxyisoquinolinium chlorides increase in the order 4-hydroxy (4.93), 8-hydroxy (5.81), 6-hydroxy (6.02), 5-hydroxy (6.90), and 7-hydroxy (7.09 in water at 25 °C, respectively) (57JCS5010). Thus, 2-methyl-4-hydroxyisoqui-nolinium chloride is the strongest acid. The UV spectra of 2-methyl-isoquinolinium-5-olate (34) and 2-methyl-isoquinolinium-8-olate (39) were also presented (61BCJ533) and the formation of a quinoid structure of 2-methyl-isoquinolinium-6-olate (38) can also be detected by means of UV-spectroscopy. 

In molecules with both an acidic and a basic function, there is in principle the possibility of an intramolecular proton transfer leading to betaines (see above). Due to the values of the functional groups, pyridine and carboxylic acid, in [66] no intramolecular proton transfer takes place and no betaine is formed. 

Solvatochromic pareuaeters, so called because they were Initially derived from solvent effects on UV/visible spectra, have been applied subsequently with success to a wide variety of solvent-dependent phenomena and have demonstrated good predictive ability. The B jo) scale of solvent polarity is based on the position of the intermolecular charge transfer absorption band of Reichardt s betaine dye [506]. Et(io> values are available for over 200 common solvents and have been used by Dorsey and co-%rarkers to study solvent interactions in reversed-phase liquid chromatography (section 4.5.4) [305,306]. For hydrogen-bonding solvents the... 

The values of dipole moments of betaines (Table IX) range from 9.2 to 10.1 D. 

The rotation barriers about the central E14-C bond in betaines of the third group are 15.3-18.2 kcal/mol. The barrier value increases in the series Si-Ge-Sn and on going from X = O to NMe. 

Most studies of micellar systems have been carried out on synthetic surfactants where the polar or ionic head group may be cationic, e.g. an ammonium or pyridinium ion, anionic, e.g. a carboxylate, sulfate or sulfonate ion, non-ionic, e.g. hydroxy-compound, or zwitterionic, e.g. an amine oxide or a carboxylate or sulfonate betaine. Surfactants are often given trivial or trade names, and abbreviations based on either trivial or systematic names are freely used (Fendler and Fendler, 1975). Many commercial surfactants are mixtures so that purity can be a major problem. In addition, some surfactants, e.g. monoalkyl sulfates, decompose slowly in aqueous solution. Some examples of surfactants are given in Table 1, together with values of the critical micelle concentration, cmc. This is the surfactant concentration at the onset of micellization (Mukerjee and Mysels, 1970) and can therefore be taken to be the maximum concentration of monomeric surfactant in a solution (Menger and Portnoy, 1967). Its value is related to the change of free energy on micellization (Fendler and Fendler, 1975 Lindman and Wennerstrom, 1980). 

The effect of micelles on these spontaneous hydrolyses is difficult to explain in terms of kinetic solvent effects on these reactions. Mukerjee and his coworkers have refined earlier methods for estimating apparent dielectric constants or effective polarities at micellar surfaces. For cationic and zwitterionic betaine sulfonate micelles Def is lower by ca 15 from the value in anionic dodecyl sulfate micelles (Ramachandran et al., 1982). We do not know whether there is a direct connection between these differences in effective dielectric constant and the relation between reaction rates and micellar charge, but the possibility is intriguing. 

Although the efficiencies of surface tension reduction, pCao, for the betaines and their corresponding sulfobetaines are almost the same, the former appear to show greater effectiveness in surface tenion reduction, as indicated by the values. This may be due... 

The latter value agrees well with the experimental values shown in Tables I and II. Tori (2) obtained a value of 0.54 nm for the C-dodecyl betaine, Ci2H25CH(C00")N (CH3)3 in water at... 

In Figure 3, the logarithm of cma is represented as a function of the number of carbon atoms in the hydrocarbon chain, n. It is found that the log cma values for the various surfactants at the same n. value, except N-alkyl betaine, become closer compared to... 

Biological assays were performed with 6 mM compound in the diet. The reproductive index of aphids fed with 12 mM of glycine-betaine was 5.1 after 72 h of feeding. Values shown are the average ( standard error) of three samples of ten aphids each. Reproduction studies were performed with five samples. 

Fragmentation of the betaines 180, R = Me, Et, -Pr, i-Pr R = Cl, NOj, CN, has been shown to proceed by intramolecular splacement of the o-substituent of the iV-aryl group and formation of the tetracyclic systems 181 as shown in Scheme 2. The subsequent breakdown pattern shown in Scheme 2 was observed for 181, R = T and 181, R = M-Pr, but not for 181, R = Me, where elimination of methylene would be necessary compounds 180, R = Me, R = NOj R = CN, underwent fragmentation by loss of CHjN from the tetracyclic species 181, R = Me. In all, seven different compounds were examined in this study and the differences noted in their fragmentation patterns assigned to the relative ease of elimination of Cl, NO2, or CN. All the compounds showed prominent ions at mie values corresponding to C7H4N+ and... 

The physical chemical behavior of betaine esters of long-chain alcohols shows strong similarities to the common, closely related alkyltrimethylam-monium surfactants both in dilute and concentrated aqueous systems, hi consistence with the findings about CMC s of surfactants containing normal ester bonds (see above) it has been found that the CMC for a betaine ester with a hydrocarbon chain of n carbons is very close to the value for an alkyltrimethylammonium chloride surfactant with a hydrocarbon chain of n + 2 carbons [32], The binary phase diagram of dodecyl betainate-water has an appearance very similar to that of an alkyltrimethylammonium surfactant with a hydrophobic tail of a similar size [30]. 

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