Arsine, physical properties

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. 

Physical Properties.—Pure arsine at ordinary temperatures is a colourless gas, with an obnoxious odour. It is extremely poisonous, its physiological effects being discussed on p. 290. 

These complexes are produced when rhodium trichloride is allowed to react with two, or less, equivalents of tertiary phosphine or arsine (equation 199). Their physical properties are listed in Table 68, and the complexes have been shown to adopt the non-centrosymmetric structure (80).977 This is in agreement with the dipole moment972 and 3IP NMR spectrum978 of the tributylphosphine... 

One interesting reaction undergone by the tri(styryl)arsine complexes is the bromination of the C=C bond by bromine in CC14 (equation 217).1013 Similar behavior970 is exhibited by the few tertiary stibine complexes (Table 75) that have been isolated. Few physical properties of these complexes have been investigated, but the 121 Sb Mossbauer parameters for both rhodium(III) complexes and the free ligands have been determined.1016... 

The other hydrogen halides add oxidatively to rhodium(I) complexes of ditertiary phosphines or arsines giving rise to numerous monohydrido complexes, whose physical properties are also listed in Table 79. However, it is possible to prepare certain monohydrido complexes from rhodium(III) halides. One interesting reaction, carried out under an atmosphere of CO, gives rise to dicar-bonyldichlororhodate(I) salts (equation 241).226... 

Tetrafluoroborate,223 tetraphenylborate and iodide227 salts of a large range of rhodium(I) complex cations react oxidatively with dioxygen (equation 242). The physical properties of the dioxygen complexes are given in Table 80. The claim that a rhodium(I) species containing a ditertiary arsine... 

The complexes of this stoichiometry containing ditertiary arsines probably outnumber those of tertiary phosphines. They have been prepared by the same general methods as the tertiary phosphine complexes, although unusually [RhCl2(diars)2]Cl has been prepared from Na3[RhCl6]. Despite the relative antiquity of this method,1044 it has not been generally adopted (equation 251). The physical properties of the ditertiary arsine complexes are listed in Table 82. It may be noted that the IR spectra of the sulfinato complexes indicate that these are S-bonded like their phosphorus analogs.230... 

Table 82 Physical Properties of [RhX2(LL)2]X Complexes Containing Ditertiary Arsines...

Lewisite [L or L-1 dichloro(2-chlorovinyl) arsine] is an arsenical vesicant developed early in the 20th century. Lewisite occurs as cis- and tranx-isomers the typical ratio being 10 90. Several impiuities including 6w(2-chlorovinyl) chloroarsine (L-2) and tnY(2-chlorovinyl)arsine (L-3) are typically present. The chemical and physical properties of the cis- and tranj-isomers are similar. 

As a final accomplishment, the reaction between (63) and the bis(electrophile) (70) afforded the 24-membered hexa(tertiary arsine) (71) in 15% yield. A 6% yield of (71) resulted from the reverse condensation, that is, the reaction of (66) with the bis(arsenide) (72) (Scheme 11). The product was isolated by column chromatography and characterized by elemental analysis and MS. The ease with which the heterocycles (64) and (69) and (71) can be purified by column chromatography is an important physical property that distinguishes them from similar tertiary phosphines and opens up the possibility for the complete separation of diastereomers. 

Lewisite is composed of cis- and trans-isomers in the ratio of 10 90 and several impurities including bis(2-chlorovinyl)chloroarsine (L-2) and tris(2-chlorovinyl) arsine (L-3) (Rosenblatt et al., 1975). The chemical and physical properhes of the cis- and trans-isomers are similar. Tlie nomenclature and chemical and physical properties of L-1, L-2, and L-3 are presented in Tables 8.5... 

Yaws, C. L. and Others, "N-Type Gas Phase Dopants - Physical and Thermodynamic Properties of Arsine, Phosphine and Stibine , Solid State Technology, IZ (1), 47 (1974). 

These arsines differ from those of the aliphatic series which have just been described, by their physical and chemical properties, and by their method of employment, as well as by their biological action. They are solids or liquids with high boiling points, have very low vapour tensions, are quite resistant to heating and are only oxidised by atmospheric oxygen with difficulty. 

The term blister agents includes a wide range of compounds with diverse physical and chemical properties and chemical structures. They may be broadly grouped under a few general types, namely, the sulfur mustards, nitrogen mustards and organochloro-arsines. There are also some substances that do not fall nnder the above categories. 

TABLE 15.1 Table Showing Physical and Chemical Properties of Arsine... 

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