Triphenylarsine

In order to understand this very peculiar chemisorption step which occurs in the real process of oil recovery and purification, triphenylarsine, and diphenylmer-cury have been used to model the real organometallic poison present in the crude oil. An industrial catalyst made of alumina-deposited nickel, containing 18wt% nickel as about lOnm diameter particles, is used (this corresponds to a dispersion of 10%). In the following, we will see that the smallest size of the nanoparticles is no longer a requirement but the control of such a size becomes a crucial problem  

AsPhs reaction in n-heptane solution, under hydrogen (12bar) at a temperature between 25 and 200 °C, with Ni/Al203 only takes place on the nickel surface and is characterized by benzene (and cyclohexane, secondary product) evolvement [115]. At 80 °C, saturation of the nickel surface has been reached with As/Nij ratio 

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. 

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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). 

In this case the ylide was not isolated but allowed to react with ben2ophenone to give, after hydrolysis with hydrochloric acid, 1,1-diphenylethylene, diphenylacetaldehyde, and triphenylarsine (160). An excellent method for preparing arsonium ylides involves the reaction between a stable dia2o compound and triphenylarsine in the presence of a copper catalyst such as bis(acetylacetonato)copper(II) (161). Rather than a dia2o compound, an iodonium yhde can be used again a copper catalyst is necessary for an optimum yield of product. An example of the use of a dia2o compound is shown in the formulation of triphenyl arsonium 2,3,4-triphenylcyclopentadienyLide [29629-32-17, C H As ... 

Reaction of lithium 2,5-dimethylpyrrolate ion with [RhCl(CO)2]2 leads to formation of 84 (88PAC1193 90P1503). This is the first example of the mixed mode, when the ti N) and ti (C=C) coordination are realized simultaneously. Nucleophilic addition of triphenylphosphine and triphenylarsine gives 85 (E = P, As). The iridium analogs of 84 and 85 have also been synthesized. 

Rhodium, hydridotetrakis(triphenyl phosphite)-, 4,923 Rhodium, hydrido(trifluorophosphine)tris-(triphenylphosphine)-, 4,921 Rhodium, hydrido(triphenylarsine)tris-(triphenylphosphine)-, 4,921,924 Rhodium, hydridotris(triphenylphosphine)-, 4, 916 preparation, 4, 916... 

Ylids are usually prepared from triphenylphosphine, but other triarylpho-sphines, trialkylphosphines, and triphenylarsine " have also been used. The Wittig reaction has also been carried out with other types of ylids, the most important being prepared from phosphonates " ... 

Fig. 1. Annealing curves (45 °C) for several products in neutron irradiated triphenylarsine. Note particularly the initial rise and subsequent fall of diphenylarsine derivatives (Redrawn from Maddock and Sutin )...

Not many organometallic systems have been subjected to extensive thermal annealing studies— the most thorough work has been done on the phenylarsenic compounds. The earliest such study was that of Maddock and Sutin on triphenylarsine. The results are in part given in Fig. 1, from which it was concluded that the reformation progresses in the stepwise fashion ... 

Contribution from Processes at Various Stages in the Triphenylarsine Benzene System"... 

Triphenylphosphine oxide (and PhsAsO or Ph2SeO) are reduced by MesSiNs 19, via the labile diazidophosphines 1780, to triphenylphosphine (triphenylarsine or diphenylselenide), nitrogen, and HMDSO 7, whereas iodosobenzene gives, via 1781, iodobenzene, nitrogen, and HMDSO 7 [30] (Scheme 12.9). 

Triphenylarsine oxide transfers its oxygen to triphenylphosphine in dichloromethane at 105 °C. 

Fig. 8 Kinetics of AsPha reaction at 303, 373 and 473 K under 12 bars of H2 on Ni/AbOa (Ni loading 25 wt%, dispersion 18%). a triphenylarsine concentration b benzene + cyclohexane evolution...

The first cyclic trinuclear compound of gold(I) was reported by Vaughan in 1970 [44], The complex [p,-N, C -pyAu]3 was obtained in a very good yield by adding triphenylarsine gold(I) chloride to a THF solution of 2-pyridyllithium at —40°C, Figure 1.32. 

Palladium-catalyzed hydroarylation of sterically hindered PTAD adduct 157 with aryl halides in the presence of triphenylarsine, sodium acetate, and DMSO provides a 1 1 mixture of 170 and 171. The same reaction done with sodium fluoride and formic acid provides mixtures containing 171 as the major product. Apparently, the use of sodium fluoride as a base allows the selective formation of the opening products 171 in good yields (Equation 19). Similarly, the 2,3-phthalazine-l,4-dione adduct 172 provides the corresponding products 173 and 174 (Equation 20) <2002AGE3375>. 

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