Cation-anion complexes

Before use, condition the new electrode by employing it in the titration of a sodium lauryl sulfate solution with a solution of Hyamine 1622 or benzetho-nium chloride solution, 0.04 M using a silver-silver chloride reference electrode. During this conditioning, a layer of an insoluble cation-anion complex becomes firmly attached to the plasticized PVC coating rendering it sensitive to both anionic and cationic surfactants. 

There are two generally accepted mechanisms for simple phase transfer reactions under neutral conditions. The first of these is a mechanism in which the whole cation-anion complex moves between the two phases as shown in Scheme 5.6 [42],... 

Of course, ions dissolved in solution move about freely, not as pcirt of cation-anion complexes. So to allow double replacement reactions to progress, one of several things must occur ... 

As far as we are aware, the number of luminescent extended systems with gold-platinum interactions is reduced to only one report. This is a puzzling situation since the situation of platinum in the periodic table suggests considerable relativistic effects for this atom and extended chains of squared-planar Pt(II) cation-anion complexes built by metal-metal interactions are not strange. In fact, salts such as [Pt(CNR)4][Pt(CN)4] ,67 which are luminescent and display vapochromic behavior, and the modified form of the Magnus salt [Pt(NH3)4][Pt(CN)4] ,68 which shows semiconducting properties, are examples of this type of supramolecular systems. Therefore, the stable combination of gold and platinum in cation/anion-acid/base systems should be anticipated. 

The C—Ph bond in compounds 432 (R = Ph) or 438 may be cleaved easily by I2 or Hgl2, leading to formation of Phi or PhHgl and the corresponding iodo derivatives or cation-anion complexes with tetrahedral tin in the cation and a Hgl3 anion555. 

Synthesis of cation-anion complexes [L,2Ge(H)(B)]+OTf (123c-B, L is the potential bidentate 8-methoxynaphthyl ligand, B = CgHsCI I2NII2, H2O, DMSO) containing... 

SCHEME 22. Schematic representation of intermolecular H-bonds in the cation-anion complex 123c H20... 

A new cation-anionic complex of hypercoordinate tin (593) was obtained by treatment of (L5)2SnCl2 (L5 is a bidentate (2-oxopyrrolidino)methyl C,0-chelating ligand) with AgBF41250. As in the case of (L7)2GeCl2 (Section VIII.A), the reaction occurs with replacement of both Cl atoms. As shown by X-ray crystallography, the reaction product, however, has a dimeric distannoxane structure, in which both tin atoms are stannacenium... 

The Pt-catalyzed hydrosilylation of trimethyl silane and alkenols or alkenyl-polyethers lead to nonionic silane surfactants, whereas the addition of allylglycidyl ether to trimethylsilane results in a precursor for ionic derivatives. The epoxy group is highly reactive towards nucleophilic agents and can be easily transformed into quaternary ammonium, betaine, or sulfonate complexes. Additionally, cation-anion complexes can be formed by the transformation of two equivalents of epoxy silane with one equivalent of trialkyl ammonium hydrogen sulfite. The reaction of hydroxyalkyltrimethylsilane... 

Garrels and Thompson (1962) performed essentially the same calculation for the major ions in seawater. Their calculations were based on the assumption that the major ions in seawater associate only into ion pairs consisting of 1 1 cation anion complexes. The activity coefficients used in this calculation and the resulting percentages of ion pairing (Table 3.5) have largely survived the test of time and can be broadly apphed in thermodynamic descriptions of the major seawater ions and their reactions. 

High-temperature ionic solvents are known to contain relatively high total concentrations of cations (e.g. in the KCl-LiCl eutectic, the concentration of Li+ is approximately equal to 8.5 mol kg-1 of the melt). Usually, cation-anion complexes in molten salts are characterized by co-ordination numbers of the order of 4-6. This means that the maximal consumption of acidic cations does not exceed 0.4-0.6 mol kg-1 in diluted solutions with concentrations close to 0.1 mol kg-1. This estimate is considerably lesser than the initial concentration of acidic cations in the pure melt. In the case of the KCl-LiCl eutectic melt, this consumption is only of the order of 5-7%, and the value of NMe+ in equation (1.3.16) may be assumed to be constant. Therefore, for each ionic solvent of the second kind (kind II) the denominator in equation (1.3.16) is a constant which characterizes its acidic properties. We shall define p/L = -log /L to be the relative measure of acidic properties of a solvent and call it the oxobasicity index of ionic melt [37, 162, 181]. Since the direct determination of the absolute concentration of free oxide ions in molten salts is practically impossible, the reference melt should be chosen— for this melt, /L is assumed to be 1 and p/L = 0. The equimolar KCl-NaCl... 

A qualitative explanation of the tendencies observed may be obtained in the framework of the complexation ability of halide anions. The alkali metal cations, whose absolute concentration in ionic melts defines their acidities, are surrounded by anions in such media, and near the anions there exists a neighbouring cation. The higher the cation-anion complex stability the lower the absolute cation concentration in the melt, which weakens its oxoacidic properties. 

CAM] Caminiti, R., Nickel and cadmium phosphates in aqueous solution. Cation-anion complex formation and phosphate - H2O interactions, J. Chem. Phys., 77, (1982), 5682-5686. Cited on page 205. 

We concluded that formation of the cationic-anionic complex inside the cuticle is necessary to produce this effect. If the cell membrane complex is damaged (e.g., by permanent waving), then penetration is enhanced. Adsorption of the cationic species occurs inside the cell membrane complex and the endocuticle. On washing with the anionic surfactant, penetration occurs, and an insoluble cationic-anionic complex deposits inside the cell membrane... 

It is possible [85] that introducing Co2(CO)8 into the toluene solution of styrene block-copolymer with 4-VPy also gives rise to the cation-anion complexes localized into a micelle having 4-VPy units (similar to DMF) with com-... 

Simultaneous cation-anion complexation, 40, is possible with appropriately constructed receptors. 

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