Secondary arsines reactions

Methylarsine, trifluoromethylarsine, and bis(trifluoromethyl)arsine [371-74-4] C2HAsF, are gases at room temperature all other primary and secondary arsines are liquids or solids. These compounds are extremely sensitive to oxygen, and ia some cases are spontaneously inflammable ia air (45). They readily undergo addition reactions with alkenes (51), alkynes (52), aldehydes (qv) (53), ketones (qv) (54), isocyanates (55), and a2o compounds (56). They also react with diborane (43) and a variety of other Lewis acids. Alkyl haUdes react with primary and secondary arsiaes to yield quaternary arsenic compounds (57). 

Reactions of secondary arsines with CS2 proceed in the same way as those of the corresponding phosphines. The phosphino- and arsino-dithioformates coordinate via one sulfur atom and the phosphorus or arsenic atom. H NMR, IR and UV-visible spectra show that the second sulfur atom of the CS2 fragment is exocyclic.101,102 Reaction of (92) with (93) gives hexacoordinated (94) with the evolution of 1 mol of CO.103... 

The tertiary arsines easily form adducts with the aluminum alkyls. The reaction of R2AICI (R = Me, i-Bu) with As[SiMc3]3 does not lead to a dehalosilylation reaction, but yields the adducts R2(Cl)AlAs[SiMe3]3. The other known As-Al bonded compounds are base-stabilized monomeric arsinoalanes and the cycloarsinoalanes. Although a few secondary arsines react with aluminum alkyls to give the cycloarsinoalanes (equations 34 and 35),6s,66,70 1 2-elimination route to arsinoalanes becomes... 

Relatively few germylarsines are known. They are usually prepared from the respective sUylarsine by a salt elimination or dehalosilylation reaction (equations 53-55). Cleavage of the Ge-N bond with a secondary arsine also leads to the formation of germylarsines (equation 56). Oxidation of the germylarsines with oxygen leads to the respective metal arsinates, R3Ge-0-As(0)R2. 

It has already been noted that the esters of arsinous and arsonous acids disproportionate of heating. The formation of As(OR)3 in the pyrolysis of arsonic acid derivatives is thought to be the product of the secondary disproportionation reaction of the primary product RAs(OR)2-... 

Reaction of primary and secondary arsines with electrophiles... 

Primary and secondary arsines have also been used for reactions with arsenic halides (equations 193 ° and 194 ). 

Reactions of primary arsines, secondary arsines and compounds having As—As bonds with organoelectrophiles... 

Where X is Br or Q, the free acids may be obtained by acidification of the alkaline solution, but where X is I, the acids must be isolated as salts to avoid reduction of the arsonic acids by HI. Rather than using alkyl haUdes, alkyl or dialkyl sulfates or alkyl arenesulfonates can be used. Primary alkyl haUdes react rapidly and smoothly, secondary haUdes react only slowly, whereas tertiary haUdes do not give arsonic acids. AHyl haUdes undergo the Meyer reaction, but vinyl hahdes do not. Substituted alkyl haUdes can be used eg, ethylene chlorohydrin gives 2-hydroxyethylarsonic acid [65423-87-2], C2H2ASO4. Arsinic acids, R2AsO(OH), are also readily prepared by substituting an alkaU metal arsonite, RAs(OM)2, for sodium arsenite ... 

Reaction of adsorbed inhibitors In some cases, the adsorbed corrosion inhibitor may react, usually by electro-chemical reduction, to form a product which may also be inhibitive. Inhibition due to the added substance has been termed primary inhibition and that due to the reaction product secondary inhibition " . In such cases, the inhibitive efficiency may increase or decrease with time according to whether the secondary inhibition is more or less effective than the primary inhibition. Some examples of inhibitors which react to give secondary inhibition are the following. Sulphoxides can be reduced to sulphides, which are more efficient inhibitorsQuaternary phosphonium and arsonium compounds can be reduced to the corresponding phosphine or arsine compounds, with little change in inhibitive efficiency . Acetylene compounds can undergo reduction followed by polymerisation to form a multimolecular protective film . Thioureas can be reduced to produce HS ions, which may act as stimulators of... 

The As—N bond is labile and this has been widely exploited in synthetic arsenic chemistry. Some idea of the versatility168 can be seen from Schemes 1 and 2. Refluxing secondary amines with tris(dimethylamino)arsine effects transamination (equation 6). These tris(dialkyl-amino)arsines undergo the general reactions in Scheme 1, enabling ready access to a wide variety of compounds, many of them finding use as ligands in transition metal complexes (see Chapter 14 of this work). 

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 ... 

Relatively few organoarsenic compounds that contain an As-B bond are known. > > In most cases, these are synthesized by the straightforward reaction of the primary, secondary, and tertiary arsine with diborane or BH3 THF (equation 29). As-B bonding also results when the BH3 moiety reacts with Sn-As and As-P-As bonded compounds (equations 30 and 31). ... 

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