Gallium compounds properties

We could show that the hypersilyl substituent is a very useful group in the synthesis of low valent gallium compounds. Not only the steric demand of this group but also its electronic properties, as theoretical studies have confirmed, contribute to its cluster stabilizing ability [18]. 

Gainum (I)—Gallium (HI) Compounds having the formula Ga2X where X = Cl, Bt, or I, ate known. The stmcture of these mixed valance compounds, Ga" (GaX4) , has been better understood in recent years (26,27). Some properties ate Hsted in Table 5. Other compounds such as Ga" (Ga2X2) , where X = Cl or Bt, have also been identified and the stmctures determined (28,29). 

Unlike boron, aluminum, gallium, and indium, thallium exists in both stable univalent (thaHous) and trivalent (thaUic) forms. There are numerous thaHous compounds, which are usually more stable than the corresponding thaUic compounds. The thaUium(I) ion resembles the alkaU metal ions and the silver ion in properties. In this respect, it forms a soluble, strongly basic hydroxide and a soluble carbonate, oxide, and cyanide like the alkaU metal ions. However, like the silver ion, it forms a very soluble fluoride, but the other haUdes are insoluble. Thallium (ITT) ion resembles aluminum, gallium, and indium ions in properties. 

Triflates of aluminum, gallium and boron, which are readily available by the reaction of the corresponding chlorides with triflic acid, are effective Fnedel-Crafis catalysis for alkylation and acylation of aromatic compounds [119, 120] Thus alkylation of toluene with various alkyl halides m the presence of these catalysts proceeds rapidly at room temperature 111 methylene chloride or ni-tromethane Favorable properties of the triflates in comparison with the correspond mg fluorides or chlorides are considerably decreased volatility and higher catalytic activity [120]... 

G for gallium. These values (see also in the next section) are consistent with the unpaired electron residing in a Ti-orbital. The stability of these compounds was attributed to the large size and electronic properties of the Si(f-Bu)3 substituents [26-28]. Computational data for the aluminum compound indicate an Al—Al distance of 2.537 A and a wide Al—Al-Si angle of 174.90° [26]. The longer distance for the aluminum species is a result of the larger covalent radius for this metal [18]. 

Indium and gallium coordination compounds containing phosphine ligands have recently aroused interest for their widespread application as intermediates in the preparation of the Group 13 - Group 14 semiconductors [4], Since the early reports about compounds with transition metal-indium bonds [51, relatively little research has been reported in this field. However there is a growing interest in the coordination chemistry and structural features of heterometallic indium [6] and gallium complexes [7] which are also attractive as potential precursors of new materials with particular properties. 

Recently, a variety of reactions according to the general synthetic route shown in Scheme 7.32 were carried out, which facilitated a study of hydrocarbonyl-bridged gallium/zirco-nium compounds [173,174]. Two representative examples of these unusually structured R2Ga(g-R1,g-R2)ZrCp2 complexes will be described and discussed with regard to their structural properties [175]. 

Because of the unique property of some of its compounds, gallium is able to translate a mechanical motion into electrical impulses. This makes it invaluable for manufacturing transistors, computer chips, semiconductors, and rectifiers. 

Chemical properties of gallium fall between those of aluminum and indium. It forms mostly the binary and oxo compounds in -i-3 oxidation state. It forms a stable oxide, Ga203 and a relatively volatile suboxide, Ga20. 

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