Acidity, Acid number anionics

Most heterocyclic anions may be considered to be derived by loss of a proton from a parent compound, which is therefore the conjugate acid. Such anions have at least one unshared pair of electrons at the anionic site. They are named by appending the suffix -ide , with elision of a terminal e (lUPAC recommendation RC-83.1.1), as in (190)-(193). The site may be specified by a locant placed immediately before the suffix, and so chosen as to be as low as possible consistent with the numbering of the skeleton of the parent compound. The locant may be omitted in order to designate an equilibrating mixture of positionally isomeric anions, which is what one usually obtains in practice. The anion of piperidine is often informally referred to as piperidide . 

A large number of inorganic compounds can be used as the activators of acid-ion (anionic) activated lactam polymerization. The activator in anionic activated lactam polymerization not only increases the process rate, but also changes the structure and functionality of a polymer formed, and, as a result an activator can regulate the properties of the end-product.1... 

Exceptions from Lipinski s rule, i.e., molecules of PSA values > 140 A2 are found to be actively absorbed by carrier-mediated transport systems (Wessel et al. 1998), as shown in Fig. 3. IB. As further detailed in Fig. 3.2, the intestinal epithelium expresses a number of such transport systems for amino acids, organic anions and cations, nucleosides, and hexoses. Among these systems are the apical sodium-dependent bile acid transporter (ASBT Annaba et al. 2007), the monocarboxylate transporter (MCT Halestrap and Price 1999), the sodium-D-glucose co-transporter (SFGT1 Kipp et al. 2003), and the nucleotide transporter SPNT1 (Balimane and Sinko 1999). In addition, the expression of a specialized transporter system for small peptides has been found in the intestinal epithelium with the di/tripeptide transporter, PepTl (Tsuji 2002), after previous functional studies by Hu et al. (1989), and the cloning of PepTl... 

The total of the number of hydrogen atoms plus negative charges is the same for the parent acid, the anion, and any hydrogen[Pg.186]

The strengths of weak adds are measured on the pfCa scale. The p/<., value is the pH at which the acid and anion concentrations are equal (Table 2.1). The smaller the number on this scale is, the stronger the acid. In solution, weak acids do not fully dissociate into ions, but form equilibria between unchanged acid molecules and their respective charged anions and protons ... 

The most common application of ion binding to stoichiometric investigations has been the use of certain acids, whose anions are tightly bound to protein, to indicate the number of cationic groups. This type of combination often results in precipitation of the complex, which permits direct... 

Liu (2007) introduced another method called soap extraction to quantify acid number. Because the anionic surfactant can be accurately determined by potentiometric titration (see Appendix A in Liu, 2007) with benzethonium chloride (hyamine 1622), it is reasonable to use this method to find the natural soap amount. Because this potentiometric titration is for the aqueous phase, the soap should be extracted into the aqueous phase as the first step. As an anionic surfactant, the natural soap may stay in the oleic phase and form Winsor type 11 microemulsion when the electrolyte strength is high. To extract the soap into the aqueous phase, NaOH is used to keep the pH high with low electrolyte strength. Also, isopropyl alcohol is added to make the system hydrophilic so that soap will partition into the aqueous phase. 

A number of years ago G. N. Lewis extended our understanding of acid-base behavior to include reactions other than proton transfers. According to Lewis, an acid is an electron-pair acceptor and a base is an electron-pair donor. Thus, carbocations are electron-pair acceptors and are Lewis acids. Halide anions are electron-pair donors and are Lewis bases. It is generally true that electrophiles are Lewis acids, and nucleophiles are Lewis bases. 

Deprotonation kinetics of intramolecularly H-bonded dicarboxylic acid mono-anions are usually a good deal easier to study systematically by the temperature jump method because of their smaller pK values that do not require such high sample solution pH s as do the azo dyes of Table I. In Table II we have representative kinetic results for several dicarboxylic acids. The first nine acids in Table II are derivatives of malonic acid, HOOCCHg-COOH, substituted at the number two carbon. Their specific rates, for deprotonation by OH have been reported previously. The kinetic data... 

The stability improvement of Ti02 suspensions is important not only for water-based paints, but also for paints based on non-polar or low-polar solvents. It is shown in [208] that Ti02 powders modified with an anionic surfactant, e.g. sodium dodecyl sulphate, are dispersed to smaller sizes, and their sedimentation stability increases. The production of water-alkyd emulsions is inhibited due to low mechanical stability. These emulsions can easily break when exposed to shear forces such as those produced by pumps, and when intensively agitated during dispersion. [209] demonstrates that most stable emulsions can be obtained with alkyds showing high acid numbers, as well as with highly polymerised alkyds of low viscosities. 

Zinc phosphate tetrahydrate, Zn3(P04)2 4H2O, (and the dihydrate) can be used with a large number of binders to give products with a wide range of applications. The acid phosphate anions they release form a protective layer of Fe/Zn phosphates on iron and steel surfaces. The acid phosphates CaHP04 and MgHP04 are sometimes used in conjunction with various organic binders [23]. In addition, Zn/Al triphosphates have also found use [51]. 

If the number of oxygens is one larger than the number in the -ic acid, the prefix per- is placed before both the acid and anion names HCIO4 is perchloric acid, and C104 is perchlorate ion. 

Nitric, sulfuric, and phosphoric acids have important variations with different numbers of oxygen atoms. The acid and anion nomenclature system in Table 6.3... 

It also reduces adsorption of the (mostly anionic) surfactant on the reservoir rock, essentially by enhancing the negative surface charge. In some cases (alkaline-polymer floods), where there are high levels of saponifiable crude oil acids present in the crude oil (high acid number) added surfactant is not even required. The polymer is present to assist in mobility control and to ensure that the injected chemical slug remains intact and promotes the formation of an oil bank ahead of it. 

Carboxylic acids and anions (CAA) have been known to exist in sedimentary basin formation waters since before the turn of the century, and have variously been proposed as essential agents in a number of geological processes, most recently as mediators of organic-inorganic clastic diagenesis (see review in MacGowan and Surdam 1990). 

---