Lithium arsenide

Lithium Arsenide, Li3As, is formed when a mixture of the elements in suitable proportions is heated to redness, or when lithium arsenate is reduced by heating with charcoal in an electric furnace.8 It is a dark brown crystalline substance of great reactivity. It is attacked by the halogen elements at the ordinary temperature with incandescence. It burns vividly when heated in oxygen it reacts violently with nitric acid, and at a comparatively low temperature it reduces many metallic oxides. 

Lithium arsenide, LigAs.—At the temperature of the electric furnace lithium arsenate is reduced by charcoal to the arsenide, a dark brown crystalline substance of great reactivity.12... 

Arsanylethyl) cyclopentadienyl ligands are easily prepared by addition of the appropriate lithium arsenide to spiro[2.4]hepta-4,6-diene (81). By this route 428—433 were obtained in moderate yields, respectively - (Scheme 75). In a similar way, spiro-... 

Synthesis of lithium (di)organoarsenide complexes is achieved by similar methods to those outlined for organophosphide complexes (see Section I,A,1) and include (i) deprotonation of a primary or secondary arsenide with a strong base such as BuLi or LiAsH2, (ii) As-Si cleavage using BuLi, or (iii) reaction of a chloroarsine with lithium. 

Liquid crystal, thermochromic material Fiber itself Lithium niobate Gallium arsenide, various phosphors... 

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). 

TRIS(TRIMETHYLSILYL)ARSINE AND LITHIUM BIS(TRIMETHYLSILYL)ARSENIDE... 

Tris(trimethylsilyl)arsine and lithium bis(trimethylsilyl)arsenide are valuable reagents for dehalosilylation and salt elimination reactions, respectively. Each compound reacts with a wide variety of metal halides to form metal-arsenic bonds.1, 2 The syntheses reported herein are a modification of the published procedures of Becker et al.,3 designed to minimize the use of Schlenk techniques and to allow researchers to prepare two very useful compounds with a minimum of danger. However, since these compounds do... 

Caution. Lithium bis(trimethylsilyl)arsenide is very sensitive to moisture and can react explosively upon exposure to air. Methyllithium is corrosive and reacts violently with water. Both compounds should be manipulated in a dry argon or nitrogen atmosphere. Lithium bis (trimethylsilyl) arsenide should not be heated above 80°C as it begins to decompose. 

Lithium bis(trimethylsilyl)arsenide is a white powder which is stable at room temperature under an inert atmosphere. It is important for stoichiometric reasons to ascertain whether there is any residual THF. This can be readily determined by H NMR spectroscopy. The H NMR spectrum in C6D6 (reference S 7.15) consists of a single resonance at 0.62. Solubility very soluble in THF and diethyl ether, and minimally soluble in nonethereal solvents. 

There is a somewhat old, but nonetheless very useful, review of the synthesis and uses of metal arsenides.114 Triphenylarsine can be cleaved in the same way as triphenylphosphine (Section 14.2.1.2) to form MAsPh2 (M = Na, K).108,115 Dimethylarsenide, Me2 As-, is best prepared and used in situ from the reaction of sodium with Me2AsI or with Me2AsH in THF.105,116 Reaction of Me AsI and Bu Li in petroleum ether enables isolation as the lithium salt.117 Sodium or lithium will cleave phenyl groups from Ph2 As(CH2 ) AsPh2 in THF or liquid ammonia to form MPhAs(CH2) AsPhM, but often products are impure.118... 

On the basis of the expected charges on the monatomic ions, give the chemical formula of each of the following compounds (a) manganese(II) telluride (b) barium arsenide (c) silicon nitride (d) lithium bismuthide (e) zirconium(IV) chloride. 

These are usually reactions of anhydrous transition and B metal halides with dry alkali metal salts such as the sulphides, nitrides, phosphides, arsenides etc. to give exchange of anions. They tend to be very exothermic with higher valence halides and are frequently initiated by mild warming or grinding. Metathesis is described as a controlled explosion. Mixtures considered in the specific reference above include lithium nitride with tantalum pentachloride, titanium tetrachloride and vanadium tetrachloride, also barium nitride with manganese II iodide, the last reaction photographically illustrated. 

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... 

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