Interaction chain anions

Anionic Surfactants. PVP also interacts with anionic detergents, another class of large anions (108). This interaction has generated considerable interest because addition of PVP results in the formation of micelles at lower concentration than the critical micelle concentration (CMC) of the free surfactant the mechanism is described as a "necklace" of hemimicelles along the polymer chain, the hemimicelles being surrounded to some extent with PVP (109). The effective lowering of the CMC increases the surfactant s apparent activity at interfaces. PVP will increase foaming of anionic surfactants for this reason. 

Anionic and cationic products generally tend to interact with each other, usually diminishing the surface-active properties of both and often resulting in precipitation of the complex formed. Amphoteric compounds can also be incompatible with anionics in acid solution but are generally compatible with cationics and nonionics. Interaction between anionic and cationic agents can sometimes be prevented by addition of a nonionic. In some cases, if an ethoxylated sulphate or phosphate is used as the anionic component a cationic compound produces no obvious precipitation, since the oxyethylene chain acts as dispersant for any complex that may be formed. 

This [(Cr)C-H]( ) [0](-) interaction between anions along the chain has been investigated by means of theoretical ab initio calculations [34]. It has been shown... 

It is likely that the predominantly positively charged amino acids of TAT and other CPPs will interact with anionic components on the surface of the cell membrane (85). This idea is supported by the observation that cell association with CPP liposomes in glycosaminoglycan-deficient Chinese hamster ovary (CHO) cells is greatly reduced and is competitively inhibited by the presence of heparin (88,93). Furthermore, the removal of the heparan sulfate chains by the action of glycosaminoglycan lyase also suppressed the transduction of the TAT protein (94). 

One of the first examples of Intramolecular Interactions In anionic polymerization was encountered In the propagation of two-ended polystyrylceslum In THF (28). Intramolecular triple ions are formed which Increase the Ionic conductance but lower the propagation rate. Reactive free anions associate with ion Pairs on the same chain to form less reactive triple Ions. 

Some carboxylate surfactants, such as long-chain fatty acids or their anionic esters with Coenzyme A, are precipitated in the presence ( fCSmd M + (Constantinides and Steim, 1986). Measurements of CMC in the presence of divalent ions should be avoided since the insoluble surfactant could introduce serious artifacts. Traces of transition-metal ions can catalyze autooxidation of some polyoxyethylene surfactants. In a recent article by Xiao (Xiao, 2006), interactions between anionic surfactant (SDS) micellar solutions and several familiar metal salt solutio b. 

Similarly, the cis-trans isomerization of pyrazolines (255a — 255b), proceeding through an open-chain anion, can be achieved in the presence of compound 1, while common bases interact with the electrophilic substituents (equation 18)217. 

In crystalline compound [Fe(77 -CsMes)2][HC204] [H2C204]o.s, the hydrogen oxalate anions and the neutral oxalic acid molecules form linear chains (see Figure 5). The chains run parallel to the columns formed by the [Fe( 7 -CsMes)2] and [Co(77 -CsMes)2] cations, and contain deca atomic dimers formed by two hydrogen oxalate anions joined together via interactions. The anions are not arranged in the usual head-to-tail chain or... 

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