Arsine metalation

Ai senobenzene. Heat to 150° C. Phenyl diethyl arsine, metallic mercury. Michaelis and Schulte, he. cit. Ber.f 1881, 14, 1952. 

The arsenate(lll) ion can be reduced by systems which generate hydrogen (for example metal/acid) to give arsine, for example... 

The toxicity of arsenic ranges from very low to extremely high depending on the chemical state. Metallic arsenic and arsenious sulfide [1303-33-9] AS2S2, have low toxicity. Arsine is extremely toxic. The toxicity of other organic and inorganic arsenic compounds varies (28). 

Arsine is formed when any inorganic arsenic-bearing material is brought in contact with zinc and sulfuric acid. The arsenides of the electropositive metals are decomposed with the formation of arsine by water or acid. Calcium arsenide [12255-53-7] Ca2As2, treated with water gives a 14% yield of arsine. Better yields (60—90%) are obtained by decomposing a solution of sodium arsenide [12044-25-6] Na As, in Hquid ammonia with ammonium bromide (14,15). Arsine may be accidentally formed by the reaction of arsenic impurities in commercial acids stored in metal tanks, so that a test should be made for... 

Tertiary arsines have been widely employed as ligands in a variety of transition metal complexes (74), and they appear to be useful in synthetic organic chemistry, eg, for the olefination of aldehydes (75). They have also been used for the formation of semiconductors (qv) by vapor-phase epitaxy (76), as catalysts or cocatalysts for a number of polymeri2ation reactions (77), and for many other industrial purposes. 

Diarsines and Diarsenes. Under certain conditions, the reduction of compounds with two organic groups attached to arsenic may give rise to tetraalkyl-or tetraaryldiarsines. Thus a number of diarsines have been obtained by the reduction of arsinic acids with phosphorous or hypophosphorous acid (100). Diarsines can also be prepared by the treatment of a metal dialkyl- or diarylarsenide with iodine (101) or a 1,2-dihaloethane (102). 

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 ... 

Both arsonic and arsinic acids give precipitates with many metal ions, a property which has found considerable use in analytical chemistry. Of particular importance are certain a2o dyes (qv) containing both arsonic and sulfonic acid groups which give specific color reactions with a wide variety of transition, lanthanide, and actinide metal ions. One of the best known of these dyes is... 

Although trialkyl- and triarylbismuthines are much weaker donors than the corresponding phosphoms, arsenic, and antimony compounds, they have nevertheless been employed to a considerable extent as ligands in transition metal complexes. The metals coordinated to the bismuth in these complexes include chromium (72—77), cobalt (78,79), iridium (80), iron (77,81,82), manganese (83,84), molybdenum (72,75—77,85—89), nickel (75,79,90,91), niobium (92), rhodium (93,94), silver (95—97), tungsten (72,75—77,87,89), uranium (98), and vanadium (99). The coordination compounds formed from tertiary bismuthines are less stable than those formed from tertiary phosphines, arsines, or stibines. 

Organo-metallic compounds, on the other hand, behave very much like organic compounds, e.g. they can be redistilled and may be soluble in organic solvents. A note of caution should be made about handling organo-metallic compounds, e.g. arsines, because of their potential toxicities, particularly when they are volatile. Generally the suppliers of such compounds provide details about their safe manipulation. These should be read carefully and adhered to closely. If in any doubt always assume that the materials are lethal and treat them with utmost care. The same safety precautions about the handling of substances as stated in Chapter 4 should be followed here (see Chapter 1). 

Arsenic exists as grey, yellow and black forms of differing physical properties and susceptibilities towards atmospheric oxygen. The general chemistry is similar to that of phosphorus but whereas phosphorus is non-metallic, the common form of arsenic is metallic. Traces of arsenides may be present in metallic residues and drosses these may yield highly toxic arsine, ASH3, with water. 

Air emissions for processes with few controls may be of the order of 30 kilograms lead or zinc per metric ton (kg/t) of lead or zinc produced. The presence of metals in vapor form is dependent on temperature. Leaching processes will generate acid vapors, while refining processes result in products of incomplete combustion (PICs). Emissions of arsine, chlorine, and hydrogen chloride vapors and acid mists are associated with electrorefining. 

Chemical Reactivity - Reactivity with Water. No reaction Reactivity with Common Materials Will corrode metal and give off toxic arsine gas Stability During Transport Stable Neutralizing Agents for Acids and Caustics Flush with water and rinse with sodium bicarbonate or lime solution Polymerization Not pertinent Inhibitor Polymerization Not pertinent. 

C. A. McAuliffe and W. Levason, Phosphine, Arsine and Stibine Complexes of the Transition Elements, Elsevier, Amsterdam, 1979, 546 pp. A review with over 2700 references. See also C. A. McAuliffe (ed,), Transition-Metal Complexes of Phosphorus, Arsenic and Antimony Donor Ligands, Macmillan, London, 1972,... 

Arsine, AsHs, is formed when many As-containing compounds are reduced with nascent hydrogen and its decomposition on a heated glass surface to form a metallic mirror formed the basis of Marsh s test for the element. The low-temperature reduction of AsCls with LiAlH4 in diethyl ether solution gives good yields of the gas as does the dilute acid hydrolysis of many arsenides of electropositive elements (Na, Mg, Zn, etc.). Similar reactions yield stibine, e.g. ... 

In view of the excellent donor properties of tertiary arsines, it is of interest to inquire whether these cyc/o-polyarsanes can also act as ligands. Indeed, (MeAs)s can displace CO from metal carbonyls to form complexes in which it behaves as a uni-, bi- or triden-tate ligand. For example, direct reaction of (MeAs)5 with M(CO)6 in benzene at 170° (M = Cr, Mo, W) yielded red crystalline compounds [M(CO)3( -As5Me5)] for which the structure... 

Arsine complexes are especially stable for b-class metals such as Rh, Pd and Pt, and such complexes have found considerable industrial use in hydrogenation or hydroformylation of alkenes. 

The cyclometallated palladium and platinum derivatives of trimesityl phosphine or arsine react with pyrazole or 3,5-dimethylpyrazole to form metal chelates 243 (E = P, As M = Pd, Pt R = H, Me) having the trans configuration (81TMC24). 

Many, but not all, bidentate phosphine and arsine ligands form 2 1 complexes with these metals. M(diars)2X2 (diars = o-C6H4(AsMe3)2) contain 6-coordinate metals frans-Pd(diars)2I2 has long Pd-I bonds (3.52 A). These complexes are 1 1 electrolytes in solution, suggesting the presence of 5-coordinate M(diars)2X+ ions. 

Complexes of the transition metals with phosphines, arsines and stibines. G. Booth, Adv. Inorg. Chem. Radiochem., 1964, 6,1-69 (460). 

Reactions involving transition metal ions and tripodal phosphines and arsines. F. Mani and L. Sac-coni, Comments Inorg. Chem., 1983, 2, 157-186 (73). 

An investigation of the chelate effect the binding of bidentate phosphine and arsine chelates in square-planar transition metal complexes. D. M. A. Minahan, W. E. Hill and C. A. McAuliffe, Coord. Chem. Rev., 1984, 55, 31-54 (153). 

The element symbols within each formula are arranged according to a modified Hill system in which the order is metal(s), C, H and then any remaining symbols arranged alphabetically. Compounds containing two (or more) different metals appear twice (or more), being listed under each metal. Common ligand abbreviations which appear in the text have also been used in the index. These include acac (acetylacetone), bipy (2,2 -bipyridyl), diars [o-phenylenebis(dimethyl-arsine)], dien (diethylenetriamine), etc. 

Complexes of the Transition Metals with Phosphines, Arsines, and Stibines G. Booth... 

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