Gallium natural state

Mixed Coordination Silicates. As described in the second chapter, there is a small group of microporous metallosilicates in which the metals possess non-tetrahedral coordination. ETS-10 is the best known of these, in which tetrahedral silicon has two types of chemical environments, Si(OSi)3 (OTi) and Si(OSi)4. The titanosilicate end-member is able to take up a range of trivalent cations into the framework upon synthesis, including boron, aluminium and gallium. Solid state NMR reveals the nature of this substitution ... 

Unlike gallium and indium, technetium may exist in a variety of oxidation states under physiological conditions, depending upon the nature of the ligands by which it is complexed. 

Aluminum alkyls, alkylaluminum halides, and alkylalu-minum hydrides strongly associate in solution and in the solid state.The association of trialkylaluminum compounds is in stark contrast to the monomeric nature of trialkylboron see Boron Organoboranei) and trialkylgallium see Gallium Organometallic Chemistrj compounds. 

The isotopes Ga and Ga with natural abundances of 60.4% and 39.6%, respectively, are both suitable candidates for solid-state NMR spectroscopy. Since the quadrupole moments of these isotopes have the same order as that of the aluminum nucleus, similar NMR Une shapes can be expected for gallium and aluminum atoms incorporated at analogous framework sites. Moreover, Bradley et al. [152] found a linear relationship between the Ga and Al chemical shifts of a series of structurally analogous aliunimun and gaUiiun compoimds with exclusively oxygen in the first coordination sphere ... 

We have not attempted to carry out any direct electrochemical syntheses in aqueous media, but there are reports in the literature of work carried out some 40 years ago on the electrochemical oxidation of a number of metals in liquid ammonia [72,73], and since two of the metals in question were gallium and indium, this seemed a natural area for further investigation. The immediate conclusion, which we established by measuring Ep, is that indium is oxidized in liquid ammonia solutions of ammonium halides at -35 °C to the -I-II state, but unfortunately we were not able to isolate any compounds of this oxidation state from the resultant solution, though in one particular case we were able to show by Raman spectroscopy that species with the characteristic j (In-In) stretching mode were present in the solution [74]. When we attempted to work up these solutions both indium and I) halide derivatives of ammonia were obtained, and a mass balance, taking into account the quantity of material isolated and the quantity of indium dissolved, showed that the typical disproportionation reactions of indium +11 were indeed being reproduced under these conditions. We concluded that the overall stoichiometry is... 

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