Arsenide complexes

Silver(I) phosphide or arsenide complexes have been synthesized. The reaction of AgCl with Ph2PTMS in the presence of a tertiary phosphine gives polynuclear complexes such as... 

Bis(trimethylsilyl)arsine reacts with diethyl- or dimethylzinc to form different arsenide complexes with the structure dependent on the steric demands of the alkyl group. In the presence of both methyl and ethyl groups alkylzinc bis(trimethylsilylarsenide) forms which has a trimeric solid state structure (37) with a six-membered Zn3As3 and Zn-As distances with an average of 2.48 A.322... 

In comparison to alkali metal complexes of (di)organophosphide ligands, complexes of these metals with (di)organoarsenide ligands are relatively rare and few have been structurally characterized. This dearth of structural information is perhaps due in part to the relatively low importance of such complexes in inorganic and organic synthesis and to the lower stability (both thermal and photolytic) of arsenide complexes compared to their phosphide analogues. 

To date only one polyanionic arsenide complex of an alkali metal has been reported. The complex [B GejAslSiPrilLijsh is obtained from the reaction of Bu GeF3 with 3 equiv of Li AsH(SiPii) and BuLi in ether in 24% yield (107). The complex contains a Ge2As6Li6 framework with a center of symmetry in a distorted rhombododecahedral arrangement (Fig. 13). Each As atom is thus bound to three Li atoms in addition to one Ge atom and one exocyclic SiPr( group the Li atoms are in contact with three As atoms and also with two H atoms from different SiPr], groups [Li-As = 2.52(2) to 2.62(2) A], Additional solvation of the Li atoms is not observed, even though the complex is syn-... 

Some interest in group 12 phosphide and arsenide complexes has come from their possible applications as precursors for IFV semiconductors (see Semiconductors). They can be prepared by two different ways, namely, by metaUa-tion reaction of phosphines and arsines with diorganozinc compounds (equation 32), and by transmetallation reaction between organozinc halides and lithium salt of the corresponding phosphines and arsines (equation 33). 

Becker et al. reported the first structurally authenticated alkali metal arsenide complex in 1982 (102). The complex [Li As(SiMes)2 (DME)]2, synthesized by the reaction of As(SiMe3)s with BuLi or MeLi in DME, crystallizes as centrosymmetric dimers containing a planar Li2As2 rhombus-shaped core [Li-As = 2.59(2) A As-Si = 2.307(7) A As-Li-As = 99(1)°]. Tetrahedral coordination of the lithium atoms is achieved by coordination to the two 0 atoms of the chelating DME hgands. Cryoscopic measurements indicate that the dimeric structure of this complex is preserved in solution. (Selected bond lengths and angles of alkali metal arsenides are listed in Table III.)... 

Owing to the fact that valence electrons determine bonds, the electrical properties of a material are related to the bond type. In conductors such as metals, alloys, and intermetallics, the atoms are bound to each other primarily by metallic bonds, and metals such as tungsten or aluminum are good conductors of electrons or heat. Covalent bonds occur in insulators such as diamond and silicon carbide and in semiconductors such as silicon or gallium arsenide. Complexes and salts have ions that are bound with electrostatic forces. Ionic conductors can be used as solid electrolytes for fuel cells because solids with ionic bonds may have mobile ions. Most polymers have covalent bonds in their chains but the mechanical... 

Phosphide and arsenide complexes have also been synthesized for the first time in non-organometallic complexes. Organometallic derivatives have yet to be reported. 

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