Aluminium and Gallium

NMR spectroscopy has been used to determine the thermodynamics of borate ester formation by three readily grafted carbohydrates. Boron specia-tion in borate-poly(amido amine) dendrimer has been performed using B NMR spectroscopy. The role of inositol in the synthesis of FAU- and LTA-type zeolites has been investigated using H, C, Na, and Al NMR spectroscopy. Ulvan-boron complex formation has been studied using B and NMR spectroscopy. The complexation of borate ions and humic acid fractions has been analysed with B and H NMR spectroscopy.  

The coagulation of hydrolysed aluminium salts has been studied using A1 NMR spectroscopy. The hydrolysis of mixed solutions of Al , Ga , Ln , and Zr has been studied by Al and Ga NMR spectroscopy. A C and A1 NMR study of the interaction between Al and tiron, salicylic acid, and phthaUc add has been reported. B, A1, and Si NMR studies of the temperature dependent structural changes in borate, borosilicate, and boro-aluminate Uquids have been reported. The interaction of aluminosilicates by HF has been investigated. Aluminium in polysilicic acid has been speciated using A1 NMR spectroscopy. C, A1 and P NMR spectroscopy has been used to study the formation of Al-NTA-phosphate complexes. The selfdiffusion coefficients of the ATP complex of Al have been studied by H and P pulsed-field gradient NMR spectroscopy. H NMR spectroscopy has been used to study the interaction of Al with phosphatidylcholine vesicles.  

Exchange processes in solutions of AICI3 and A1(N03)3 have been investigated in water-DMSO mixtures by NMR spectroscopy, and in DMF by Al NMR spectroscopy.The encapsulation of [R4N] in [Ga4L6] , H4L = (76), has been investigated by NMR spectroscopy. 

Indium. Relaxation measurements have been used to study the formation of indium chloride complexes. 

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Amorphous boron and the amphoteric elements, aluminium and gallium, are attacked by aqueous solutions of sodium hydroxide and... 

A. Schnepf, H. Schnockel, Metalloid aluminium and gallium clusters element modifications on a molecular scale Angew. Chem. Int. Ed. 41 (2002) 3532. 

Greenwood, N. N., and /. A. McGinnety Reactions of Decaborane with Adducts of Aluminium and Gallium Hydride Chem. Comm. 1965, 331. 

Molten aluminium and gallium fluxes have shown themselves to be excellent routes to complex ternary and quaternary intermetallic phases such as R-T-Al and R-T-Al-Si, R-T-Al-Ge (when Al is used as solvent) or R-T-Ga, R-T-Si, R-T-Ga-Si, R-Ga-Ge (when Ga is used as solvent), where R = rare earth metal, T = transition metal. 

Finally, for MPV reduction we find nearly equal barriers for aluminium and gallium, and a much lower one for magnesium. Again, one should be careful not to attach too much value to these numbers, since for magnesium-catalyzed MPV, in particular, the metal will probably prefer a higher coordination number than 4. 

Elhabiri, M. et al., Anthocyanin-aluminium and -gallium complexes in aqueous solution, J. Chem. Soc., Perkin Trans. 2, 355, 1997. 

Table 8.1 Metal-nitrogen bond lengths in isoleptic aluminium and gallium amides...

The imide [(MeInNC6F5)4] 5" was synthesized by a similar method. The tetrameric cubanes [In4X4(p-NBu )4] (where X Cl, Br or I) formed from the corresponding indium trihalide, InXa and LiHNBu have In4N4 heterocubane structures that are similar to their aluminium and gallium counterparts. The chloride [In4Cl4(NBu )4] is shown in Figure 8.11. 

The chemistry of indium complexes of aU types in metal oxidation states lower than +3 has been comprehensively reviewed. Few lower oxidation state mononuclear amido complexes of indium are well characterized, however, and no structure has been reported for an In(I) amide. The compound In N(SiMe3)2 n. which is unstable, " has been characterized NMR spectroscopy but its structure is unknown. The structures of several In(I) complexes, related to amides but outside our current scope, have been described. Like its aluminium and gallium counterparts, the p-diketuninate derivative [ In N(Dipp)C(Me) 2CH] has been characterized, as has the closely related species [ In N(Dipp)C(CF3) 2CH]. ° These feature V-shaped, two-coordination at the metal. The less bulky [(In N(Mes)C(Me) 2-CH)2] ° and 15-2.6-.Vlc,)( (Me) i are dimeric with long In In bonds of... 

As mentioned in Section IV.C, the replacement of boron by its heavier congeners aluminium and gallium markedly affects the coordination behavior of the DPE ligands (E = group 13 element) toward AuCl. In particular, the zwitterionic and neutral forms of the diphosphine-gallane complex 103 were shown to coexist and interconvert in solution.27... 

The alumino and gallophosphates were formed [7] in the systems amine-Al(Ga)203—P205—H20 using the same way of the synthesis and the same range of temperatures and pressure. However, the introduction of phosphoric acid in the synthesis lowered the pH of the solutions to a neutral or weakly acidic medium which favours higher coordinations for aluminium and gallium ions. The combined effect of pH and of the shape of the amines lead to ca two hundred structure types. 

Overall, the metalloid aluminium and gallium clusters bear some relationship to fragments of the bulk metals, protected and stabilised by the ligands on the surface, and as such can be considered intermediate between molecules and metals. They show a marked sensitivity to preparative conditions and the steric influence of the ligands on the surface. Spectroscopic studies and theoretical calculations on the clusters are not discussed here but are summarised in recent review articles, and these additional studies provide a... 

H. Schnockel and C. Klemp, Molecular Aluminium and Gallium Subhalides, in Inorganic Chemistry Highlights , eds... 

Addition of aluminium and gallium trichloride to phosphorus ylides 96a-96c leads to the formation of the heterocyclic salts 97a-97c (Scheme 34). 

Indium (10 % of the earth s crust) is also present in zinc blende, but rarely above 0.1%. It can be precipitated from solution by zinc and purified electrolytically. Its tetragonal unit ceU is a very slightly distorted version of the f.c.c. of a true metal (Fig. 152). The metal is soft. It differs from aluminium and gallium in its insolubility in boiling caustic alkalis otherwise its reactions are similar. 

Bridge bonds (p. 220), of the kind formed by boron (the first member of Gp.III), are also formed by both aluminium and gallium, though less frequently. An example is... 

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