Arsine derivatives halogens

The phenyl derivatives of these acids were known as early as 1876, owing to the fact that they are obtainable from halogenated arsines when the latter are treated with water. The older methods for isolating arylarsinic acids consist in decomposing aryl or diarylarsine halides, tetrahalides, or oxyhalides by water ... 

Reduction by Hydrazine. This was a very successful method for preparing the palladium (0) and platinum (0) derivatives with tertiary phosphines, phosphites, and arsines (4, 129, 130, 133). Also, the tetra-isocyanidenickel(O) compounds can be obtained at high yield in this way (132). In the case of platinum this reduction can give place either to zero valent derivatives (130) or to platinum (II) hydrides (49), according to the reaction conditions, the nature of the ligands, and the halogen atoms bound to the metal. This reduction is a very complicated reaction (186) in any case. 

Usually arsines of the type R3AS, R2ASX, or RA8X2 add halogens to form the pentavalent derivatives R3ASX2, R2ASX3, and RAsXa, respectively. On heating, these decompose with loss of RX 105) ... 

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