Arsenides reactions with

The reaction of the lithium bis(trimethylsilyl)arsenide (47) with -butyl phosphaethyne (45) <89TH 423-01,93PS(77)45,94JOM(480)45> or a phosphaalkene precursor thereof (46) leads to a mixture of lithium 1,2,4-triphospholide, 1,2,4-diphosphaarsolide (48) and 1,4,2-diphosphaarsolide (49) (Scheme 11). 

AsHa + CI2 — AsHaCl + HCl 2 AsHs 3 CI2 2 ASHCI2 + 4 HCl Reaction with mercuric chloride gives mercuric arsenide, HgsAs2 ... 

Reactions with phosphorus, arsenic and antimony form phosphide, arsenide, and antimonide of potassium, respectively ... 

Arsenic does not combine directly with carbon, silicon or boron. The reaction with metals to form definite arsenides or alloys is described no pp. 57-78. The presence of small quantities of arsenic or of its compounds in certain catalysts has a poisoning effect. The first traces added to the catalyst have the greatest effect thus the activity of 0-35 g. of platinum was reduced linearly by the addition of arsenic up to 0-7 mg., this quantity reducing the catalytic activity to 45 per cent, of its original value the addition of 10 mg. of arsenic, however, depressed the activity only to 26 per cent, of the original value.3 Vanadium catalysts are poisoned by the presence of arsenic, although the action is slow arsenic pentoxide is formed.4... 

As mentioned in Chapter II, many metallic arsenides are found in Nature. Arsenic combines directly with most metals to form stable compounds, those of the heavy metals being the most stable. The latter may be obtained by allowing an aqueous solution of a salt of the appropriate metal to drop into an atmosphere of arsine, air being completely absent, and the vessel continually shaken.1 Precipitation by passing arsine into the salt solution is not satisfactory as, in the case of copper, silver, gold, mercury and lead, a secondary reaction with the excess of metallic ions occurs ... 

The trend observed with the polycyclic hydrocarbons (see preceding section), namely that the product radical anions (ArNu ) are more stable than those derived from the simple benzene analogs, is even more evident with the heteroaromatic substrates and, as a consequence, fragmentation processes are minimized.41 For example, 2-chloroquinoline is the only substrate of many studied to undergo a substitution reaction with PhCH2S- ion without fragmentation of the benzyl-S bond,103 and to react with diphenyl-arsenide ion without scrambling of the aryl moieties.25... 

The reaction of lithium bis(trimethylsilyl)arsenide 16 with the phosphaalkyne 17 yields an approximately equimolar mixture of lithium 1,2,4- and 1,4,2-diphosphaarsolide 18 and 19 as has been reported in CHEC-II <1994JOM45, 19950M4382, 1996CHEC-II(4)819>. Alkylation of this mixture with bis(trimethylsilyl)bromomethane in DME gives exclusively the 177-1,2,4- and 1 //-l, 4,2-diphosphaarsolcs 20 and 21 (Scheme 3). The two isomers could not... 

Reactions with active metals to form phosphides, arsenides, etc., are important chiefly in connection with preparation of Group Vb hydrides. 

Reaction of arsenide anions with organic electrophiles... 

This method has also been quite useful for the synthesis of triorganoarsenic compounds. Arsenide anions, which can be prepared by several methods (vide infra), react with alkyl and aryl halides. Several examples are shown in equations 18 , 19 , 20 °, 21 , 22 23 , 24 and 25 . In the reaction with alkyl halides inversion of configuration at the sp carbon atom takes place and in the reaction of vinyl halides retention of configuration has been observed (equations 18 and 21). Photostimulated reaction with aryl halides has been reported to proceed via the Sjj l mechanism thus, the ketone group is compatible with the reaction conditions as shown in equation 23 . 

Reaction of arsenide anions with protic acids such as water gives the corresponding hydrides (equations 117 and 118 ). 

Analogous to the reaction of 2-chlorodimethylsilyl-l,3-dichloropentamethyltrisilane (5) with Na/K phosphide described in the literature [2], the reaction with the Na/K arsenide in monoglyme yields 1 as the main product. 1 can be crystallized from n-heptane. 

HYDROGEN ARSENIDE (7784-42-1) A thermallyunstable flammable gas. Violent reaction with acids, halogens, chlorine, oxidizers. This chemical is endothermic can be detonated by shock, elevated temperatures above (572°F/300°C), or powerful initiators. Exposure to light causes moist material to decompose with deposition of solid black arsenic. Low conductivity may cause the accumulation of static electrical charges, and cause ignition of its vapors. 

An interesting feature of the reactions of the bis(arsenide) (55) and the bis(phosphide) (58) is the stereoselective nature of many of their reactions with bis(electrophiles). Thus, except for (56 X = S), where a trace of the R, R ) diastereomer was evident, the reactions in each case afforded the... 

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