Arsenic, triphenylarsine

Trialkyl- and triarylarsine sulfides have been prepared by several different methods. The reaction of sulfur with a tertiary arsine, with or without a solvent, gives the sulfides in almost quantitative yields. Another method involves the reaction of hydrogen sulfide with a tertiary arsine oxide, hydroxyhahde, or dihaloarsorane. X-ray diffraction studies of triphenylarsine sulfide [3937-40-4], C gH AsS, show the arsenic to be tetrahedral the arsenic—sulfur bond is a tme double bond (137). Triphenylarsine sulfide and trimethylarsine sulfide [38859-90-4], C H AsS, form a number of coordination compounds with salts of transition elements (138,139). Both trialkyl- and triarylarsine selenides have been reported. The trialkyl compounds have been prepared by refluxing trialkylarsines with selenium powder (140). The preparation of triphenylarsine selenide [65374-39-2], C gH AsSe, from dichlorotriphenylarsorane and hydrogen selenide has been reported (141), but other workers could not dupHcate this work (140). 

Arsinol Phenyldichloroarisne (50%), Diphenylchloroarsine (35%), Triphenylarsine (5%) and Arsenic Trichloride (5%) Mixture Cl 4-A... 

A. Triphenylarsine. In a 2-1. round-bottomed three-necked flask is placed 130 g. (5.65 gram atoms) of powdered sodium covered with 900 ml. of benzene. The flask is fitted with an Allihn condenser, a mercury-sealed mechanical Hershberg stirrer, and a 500-ml. dropping funnel in which is placed a mixture of 170 g. (0.94 mole) of arsenic trichloride and 272 g. (2.42 moles) of chlorobenzene. About 10 ml. of the arsenic trichloride-chlorobenzene mixture is dropped into the flask, and the reaction mixture is stirred and heated on a steam bath until it darkens and boils spontaneously. The steam bath is removed, and the remainder of the arsenic trichloride-chlorobenzene mixture is added drop-wise, with stirring, over a period of 1-1.5 hours at such a rate that gentle boiling is maintained (Note 1). When the addition is complete, the mixture is stirred and heated under reflux on a steam bath for 12 hours. 

Triphenylarsine has been prepared by the action of arsenic triiodide or arsenic trichloride on phenylinagnesium Ijromide... 

Supplement 1951 2085-2358 Diazobenzene, 428. Azoxy Compounds. Azoxybenzene, 621. Nitramines and Nitroso-hydroxylamines., Phenylnitramine, 661. Triazines. Diazoaminobenzene, 687. Phosphorus Compounds. Triphenylphosphine, 759. Arsenic Compounds. Triphenylarsine, 828. Phenylarsonic acid, 868. Antimony Compounds, 891. Bi, Si, Sn, Pb, B, Tl, Mg, Ca, Hg, Na, Pt. 

SFC has received attention as an alternative separation technique to liquid and gas chromatography. The coupling of SFC to plasma detectors has been studied because plasma source spectrometry meets a number of requirements for suitable detection. There have been two main approaches in designing interfaces. The first is the use of a restrictor tube in a heated cross-flow nebuliser. This was designed for packed columns. For a capillary system, a restrictor was introduced into the central channel of the ICP torch. The restrictor was heated to overcome the eluent freezing upon decompression as it left the restrictor. The interface and transfer lines were also heated to maintain supercritical conditions. Several speciation applications have been reported in which SFC-ICP-MS was used. These include alkyl tin compounds (Oudsema and Poole, 1992), chromium (Carey et al., 1994), lead and mercury (Carey et al., 1992), and arsenic (Kumar et al., 1995). Detection limits for trimethylarsine, triphenylarsine and triphenyl arsenic oxide were in the range of 0.4-5 pg. 

Arsenic was analysed chromatographically by Schwedt and Russel [617], It was first extracted from biological material into chloroform as the dithiocarbamate, which was converted into triphenylarsine(III) by the treatment with phenyl-Grignard reagent. In this form it was subjected to GC analysis with the use of an FID. Concentrations of arsenic down to 2 jug per gram of biological sample was measured. 

Several phosphorous compounds having a P=S bond are also catalysts for this reaction. For example, heating of phenyl isocyanate with triphenylphosphine sulfide at 160 °C affords diphenylcarbodiimide. Since triphenylphosphine sulfide was recovered unchanged, a different mechanism seems to be operative. A tricyclic P S compound, S=P[N(Me)CH2CH2l3N, also catalyzes the transformation of isocyanates to carbodiimides. Triphenylarsine oxide and triphenylantimony oxide also catalyze the conversion of isocyanates into carbodiimides. The catalytic activity of the oxides of phosphorous, arsenic and antimony are in agreement with the dipole moments of... 

A solution of 300 g. (3.22 moles) of aniline in 400 ml. of water and 1 1. of concentrated hydrochloric acid is diazotized by the addition at 0-10° of a solution of 220 g. (3.20 moles) of sodium nitrite in 250 ml. of water. The mixture is held at 0° and stirred while a solution of 280 g. (2.05 moles) of zinc chloride in 120 ml. of dilute hydrochloric acid is added slowly. The precipitated salt (90 yield) is filtered off by suction, pressed free of water, and washed with dry acetone (500 ml.) until free of all moisture. A mixture of 600 g. of the dry zinc salt, 1.5 1. of dry acetone, and 180 g. (1.0 mole) of arsenic trichloride (Caution—toxic substance) is stirred vigorously and held below 5° while 220 g. of zinc dust is added in small portions over a 2-hour period. The mixture is heated under reflux for 15 minutes and filtered, and the filtrate is evaporated on a water bath. The residual oil is stirred with 200 ml. of dilute hydrochloric acid, and the solid product (300 g.) is removed by filtration. This crude triphenylarsine is converted to the pure material (m.p. 60°) by melting it under an equal weight of methanol, cooling, and collecting the residual crystalline solid. 

Phenyl dichloroarsine may also be obtained by heating triphenylarsine with arsenic trichloride in a closed tube to 250° C. for 30 hours ... 

With aliphatic aldehydes, condensation takes place in the presence of concentrate hydrochloric add at room temperatures, yielding derivatives of the type shown in equation (1). In the ease of aromatic aldehydes the reaction takes place with or without a solvent when dry hydrogen chloride is passed in. Heating these condensation products in the free flame decomposes them, with formation of aldehyde and phenylarsine, the latter being immediately oxidised to arsenobenzene in air, this in turn being transformed completely to triphenylarsine and arsenic ... 

Triphenylarsine is formed by acting on chlorbenzene and arsenic trichloride with sodium,... 

Tlie triphenylarsine is then heated under pressure with more arsenic trichloride and diphenylchlorarsine is thus obtained. 

The percentage recoveries obtained by the above digestion followed by atomic absorption spectrometric determination are given in Table 1. The recoveries obtained by the same method when applied to arsenic spiked water samples are shown in Table 2. Figure 1 shows the effect of ultra-violet irradiation as a function of time for triphenylarsine oxide, disodium methanearsonate and dimethylarsinic acid. The extent of arsenic recovery using... 

TABLE 2. Recovery of arsenic from triphenylarsine oxide, disodium methanearsonate and dimethylarsinic acid spiked into a water samples A and B with wet digestion employing 15ml of 30% hydrogen peroxide and 5 ml of sulphuric acid with analysis by silver diethyldithioearbamate ... 

FIGURE 1. Recovery of arsenic after ultra-violet exposure as a function of time triphenylarsine oxide disodium methanearsonate dimethylarsinic acid. Reproduced from Reference 69 by permission of Interscience Publishers... 

Kolthoff and Belcher showed that a 15-min exposure to UV of triphenylarsine oxide resulted in greater than 99% photodecomposition of the compound. The monoalkylated arsenic compound reacted much more slowly, requiring 2 h for complete decomposition so, obviously, this method has to be used with caution. Four-hour decomposition produced 100-110% conversion of three other organoarsenic compounds. 

Stringer and Attrep compared hydrogen peroxide-sulphuric acid digestion and U.V. photodecomposition methods for the decomposition in water samples of triphenylarsine oxide, disodium methane-arsonate and DMAA to inorganic arsenic prior to reduction to arsine and determination by atomic absorption spectroscopy or by the AgDDC spec-trophotometric method . 

A relatively simple digestive method employing 30% hydrogen peroxide in the presence of sulphuric acid was reported by Kolthoff and Belcher and subsequently used by Dean and Rues to determine arsenic in triphenylarsine. 

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