Tetraphenylarsonium

Tetraphenylarsonium chloride (107,108) has also been used for the precipitation of the perchlorate ion in gravimetric analysis. 

Tetraphenylarsonium iodide [7422-32-4] M 510.2. Crystd from MeOH. POISONOUS. 

Without some additional relationship it is impossible to resolve y into and "y. By introducing an extrathermodynamic assumption as this additional relationship, it becomes possible to estimate single ion transfer activity coefficients. A widely used assumption is that the transfer activity coefficients of the cation and anion of tetraphenylarsonium tetraphenylboride, Ph4As BPh4, are equal, i.e.,... 

Determination as the tetraphenylarsonium compound Discussion. Any ions forming a precipitate with tetraphenylarsonium chloride (e.g. MnO, ClOj, Br , I-, I03 and SCN-) will interfere. Difluorophosphates give slight interference which can be overcome by boiling the solution for a few minutes to hydrolyse difluorophosphate the hexafluorophosphate ion is not affected by this treatment. 

Tetrabutylammonium hydroxide 716 Tetraphenylarsonium chloride, 482 Thallium, D. of as thallium(I) chromate,... 

Analytical. It can be titrated with std base to a salmon colored phenolphthalein endpoint and can be quanty pptd from aq solns with tetraphenylarsonium chloride KSp of the complex in w is 6.9 x 10 9 (Ref 22). This procedure can be adapted to the analysis of compds, such as bis-(trinitroethyl) urea, which regenerate... 

It was found that chlorides, chlorates, and nitrates interfere by forming in sol ppts (Ref 6). Later it was found that w sol perchlorates could be analyzed gravimetrically by pptn of the perchlorate ion as tetraphenylarsonium perchlorate (Ksp at 20° = 2.60 0.14 x 10"9). The ppt can be (Tried at 105° and weighed directly (Ref 16). Still more recently a specific perchlorate ion electrode has been developed (Ref 17) which can be used for the potentiometric titration of the perchlorate ion using a soln of tetraphenylarsonium chloride as the titrant (Ref 15). Tetra-phenylphosphonium chloride has been similarly used, but the corresponding Sb compd is too insol in w for practical use (Ref 8), For routine assay of perchlorates for use by the armed forces, a Na carbonate fusion procedure is described in Mil Specs MlL-A-23946 (19 Aug 1964) MIL-A-23948 (19 Aug 1964) (see also under Ammonium Perchlorate). The tetraphenylarsonium chloride procedure has also been proposed for use in Mil Specs (Ref 11)... 

The exchange of Mo between the anions Mo(CN)g and Mo(CN)g has been investigated by the isotopic method ( Mo) and the separation methods (a) precipitation of Mo(CN)g with either ethanol or cadmium ions, and (b) precipitation of Mo(CN) with tetraphenylarsonium chloride. Complete exchange was observed by Wolfgang even with reactant concentrations 5x10 M. An estimate of the rate coefficient at 2 °C of >10 l.mole . sec has been sug-geMd. 

The exchange between the ruthenium anions RuO and RuO " in aqueous hydroxide media has been found rapid. A limit for the rate coefficient at 0 °C of > 1.7x10 l.mole . sec has been proposed by Luoma and Brubaker. The isotopic method ( ° Ru), and separation procedures based on the precipitation of the Ru04 or RuOJ species with barium or tetraphenylarsonium ions, respectively, were used. Attempts to use an esr technique failed. 

Beck, W. and Noth, H. (1984) Rontgenstruktur von tetraphenylarsonium-tetraazidoaurat(III). Chemische Berichte, 117, 419 Beck, W., Klapotke, T.M., Kliifers, P., Kramer, G. and Rienacker, C.M. (2001) X-Ray crystal structures and quantum chemical calculations of tetraphenyl-arsonium tetraazidoaurate(III) and azido... 

The standard Gibbs energy of electrolyte transfer is then obtained as the difference AG° x ° = AG° ° - AG° x. To estabfish the absolute scale of the standard Gibbs energies of ion transfer or ion transfer potentials, an extrathermodynamic hypothesis must be introduced. For example, for the salt tetraphenylarsonium tetraphenyl-borate (TPAs TPB ) it is assumed that the standard Gibbs energies of transfer of its ions are equal. 

Suitable electrolytes for the aqueous phase (w) comprise, for example, LiCl, HCl, MgCl2, MgS04, while suitable electrolytes for the organic phase (o) comprise salts of, for example, tetrabutylammonium, tetraphenylarsonium, or bis(triphenyl-phosphoranylidene)ammonium cations with tetraphenylborate, tertrakis(4-chloro-phenyl)borate, or tetrakis[3,5-bis(trifluoromethyl)phenyl]borate anion. 

Four-coordinate, planar iron(II)-dithiolate complexes also exhibit intermediate spin. The first example described was the tetraphenylarsonium salt of the square-planar bis(benzene-l,2-dithiolate)iron(II) dianion, (AsPh4)2[Fe(II)bdt2], which showed 5 = 0.44 mm s and AEq = 1.16 mm s at 4.2 K [157]. The electronic structure of a different salt was explored in depth by DFT calculations, magnetic susceptibility, MCD measurements, far-infra red spectroscopy and applied-field Mossbauer spectroscopy [158]. 

The electrochemisty of ITIES is developing mainly on the basis of the studies of the water-nitrobenzene and water-1,2-dichloroethane interfaces. The polarizability ranges of these interfaces in the presence of typical electrolytes (Scheme 13) are about 0.30 V. Extension of these ranges has been achieved using other organic ions or/and solvents [2,8]. For example, TBA ions may be substituted by tetraphenylarsonium crystal violet cations and TPhB ions by dicarbollyl cobaltate (III) anions [1,2]. 

Standard ionic potentials Ajy can be calculated from the ionic distribution coefficients or transfer energies see Eq. (30). In order to perform such calculations, an appropriate nonthermodynamic assumption that allows division of the E> mx) or electrolyte function into ionic constituents has to be made. At the present time, the assumption about the equality of the transfer energies of tetraphenylarsonium cations (TPhAs ) and tetra-phenylborate anions (TPhB ) is considered as most appropriate [2,36]. It can be presented in the following form ... 

The organic solvent should feature a low solubility in water and a high dielectric constant. Numerous studies have been reported for liquid-liquid junctions involving DCE [43,62,70,71,73], nitrobenzene [67,68,74,75], and nitrophenyloctylether (NPOE) [56]. Various hydrophobic electrolytes have been employed in these solvents. Tetraphenylarsonium (TPAs+) [[71,75,76], bis-triphenylphosphoranylidene (BTPPA+) [43,50], and hydrophobic tetra-arylammonium [77,78] are among the cations used in the organic phase. The choice for anions has been mostly restricted to borate derivatives, tetraphenylborate (TPB ) [70,79,80], tetrakis(4-chlorophenyl)borate (TPBCH) [43,81,82], and tetrakis(penta-fluoro)phenylborate (TPFB ) [49,83], as well as dicarbollyl-cobaltate [75]. 

In early work on the effect of potential on ET reactions [76], Solomon and Bard showed that an ET reaction between Fe(CN)g in an aqueous phase and 7,7,8,8-tetra-cyanoquinodimethane (TCNQ) in 1,2-dichloroethane (DCE) could be promoted by judiciously adjusting the potential drop across the ITIES, using tetraphenylarsonium cation as a potential determining ion. In a similar period, Selzer and Mandler [77] reported a study of the ET reaction between aqueous IrClg and Fc in a NB phase, without any potential determining ion in either phase. A first-order rate constant of 0.013 cm s was obtained... 

Here, TPhAs and DPA denote tetraphenylarsonium ion and dipicrylaminate ion, respectively. 

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