Oxygen indium

With oxygen, indium forms three compounds, InO, In2Ot, and IniO . 

In the absence of oxygen, gallium and indium are unaffected by water. Thallium, the most metallic element in Group III, reacts slowly with hot water and readily with steam to produce thallium(I) oxide, TI2O. 

The conventional electrochemical reduction of carbon dioxide tends to give formic acid as the major product, which can be obtained with a 90% current efficiency using, for example, indium, tin, or mercury cathodes. Being able to convert CO2 initially to formates or formaldehyde is in itself significant. In our direct oxidation liquid feed fuel cell, varied oxygenates such as formaldehyde, formic acid and methyl formate, dimethoxymethane, trimethoxymethane, trioxane, and dimethyl carbonate are all useful fuels. At the same time, they can also be readily reduced further to methyl alcohol by varied chemical or enzymatic processes. 

The usual valence of indium is three, although monovalent and bivalent compounds of indium with oxygen, halogens, and Group 15 (VA) and 16 (VIA) elements ate well known. The lower valence compounds tend to disproportionate into the trivalent compound and indium metal the trivalent compounds ate stable. 

Semiconductors. Phosphine is commonly used in the electronics industry as an -type dopant for siUcon semiconductors (6), and to a lesser extent for the preparation of gaUium—indium—phosphide devices (7). For these end uses, high purity, electronic-grade phosphine is required normally >99.999% pure. The main impurities that occur in phosphine manufactured by the acid process are nitrogen [7727-37-9] hydrogen [1333-74-0] arsine [7784-42-17, carbon dioxide [124-38-9], oxygen [7782-44-7], methane [74-82-8], carbon monoxide [630-08-0], and water [7732-42-1]. Phosphine is purified by distillation under pressure to reduce the level of these compounds to <1 ppm by volume. The final product is sold as CYPURE (Cytec Canada Inc.) phosphine. 

Indium [7440-74-6] In, is sometimes used as a scavenger of oxygen. It promotes uniform grain size and casting fluidity. 

Nomura, R. Fujii, S. Kanaya, K. Matsuda, H. 1990. Oxygen- or sulfur-containing organoindium compounds for precursors of indium oxide and sulfide thin films. Polyhedron 9 361-366. 

Y. Wu, C.H.M. Maree, R.F. Haglund Jr., J.D. Hamilton, M.A. Morales Paliza, M.B. Huang, L.C. Feldman, and R.A. Weller, Resistivity and oxygen content of indium-tin oxide films deposited at room temperature by pulsed-laser ablation, J. Appl. Phys., 86 991-994 (1999). 

S. Honda, M. Watamori, and K. Oura, The effects of oxygen content on electrical and optical properties of indium tin oxide films fabricated by reactive sputtering, Thin Solid Films, 281-282 206-208, 1996. 

J.A. Chaney and P.E. Pehrsson, Work function changes and surface chemistry of oxygen, hydrogen, and carbon on indium tin oxide, Appl. Surf. Set, 180 214—226, 2001. 

Scheme 9.36 Transition states for additions of allenyl indium reagents to a-oxygenated aldehydes.

Tab. 3.5-3. Structurally characterized oxygen compounds of aluminum, gallium and indium (the heterocubane type compounds have been included in Table 3.5-2).

---