Effective indium compounds

OSHA PEL TWA 0.1 mg(In)/m3 ACGIH TLV TWA 0.1 mg(In)/m3 SAFETY PROFILE A poison by subcutaneous route. It affects the liver, heart, kidneys, and the blood. Teratogenic effects. Inhalation of indium compounds may cause damage to the respiratory system. Hydrated indium oxide is a poison by... 

Table 4.1-86 Effective masses of electrons (nin) and holes (nip) for indium compounds (in units of the electron mass mo)...

The observation of more wetikly a regated oligomeric species for the heavier metals is in accord with observations made for related Cp M compounds (M = Al-Tl). Thus, although all four compounds vaporize as monomeric species [145-148], the aluminum compound crystallizes as a tetramer, with mean Al-Al distances (2.769 A), which are not markedly different from 28 (2.739 A), and which are shorter than the intermettJlic separations in aluminum metal (2.86 A) [131]. By contrast, both the gtdlium and indium compounds crystallize as loosely bound hexamers (Cp M)g, which have structures that can be viewed as octahedra, distorted by compression along a C3 axis [147, 149]. In addition, and in contrast to (Cp Al)4, the r -Cp centroid-M vectors lie not radial to the metal core, but tilted to give overtJl 5j symmetry. One interpretation of these structural distortions is in terms of a second order Jtihn-Teller effect, which maximizes M-M orbital overlap ... 

Reaction with Allylic Halides, Alcohols, and their Derivatives. Allylation of allyl and propargyl trimethylsilyl ethers as well as benzyl and propargylic alcohol derivatives proceeds in the presence of a catalytic amount of Lewis acids, such as ZnC, TMS(OTf), and B(C6F5)3. Direct substitutions of the hydroxyl group of allylic, ben-zylic, and propargylic alcohols are catalyzed by HN(S02F)2, a rhenium-oxo complex, and InCls (eq 27). A combination of chlorodimethylsilane and allyltrimethylsilane effectively promotes the deoxygenative allylation of aromatic ketones in the presence of a catalytic amount of an indium compound, such as indium trihalide or metallic indium (eq 28). Allylation of cyclic allylic acetates with allyltrimethylsilane can be catalyzed by molecular iodine. ... 

Among all the nucleophilic addition reactions of carbonyl compounds, allylation reaction has been the most successful, partly due to the relatively high reactivity of allyl halides. Various metals have been found to be effective in mediating such a reaction (Scheme 8.4). Among them, indium has emerged as the most popular metal for such a reaction. 

Palladium catalyzes allylation of carbonyl compounds with various ally lie compounds using In-InCl3 in aqueous media (Eq. 8.66).158 Various allylic compounds can be effectively applied via the formation of TT-allylpalladium(II) intermediates and their transmetalation with indium in the presence of indium trichloride in aqueous media. 

The reaction of an a-halo carbonyl compound with zinc, tin, or indium together with an aldehyde in water gave a direct cross-aldol reaction product (Eq. 8.90).226,227 A direct Reformatsky-type reaction occurred when an aromatic aldehyde reacted with an a-bromo ester in water mediated by zinc in low yields. Recently, it was found that such a reaction mediated by indium was successful and was promoted by son-ication (Eq. 8.91).228 The combination of BiCl3-Al,229 CdCl2-Sm,230 and Zn-Et3B-Eb0231 is also an effective mediator. Bismuth metal, upon activation by zinc fluoride, effected the crossed aldol reaction between a-bromo carbonyl compounds and aldehydes in aqueous media. The reaction was found to be regiospecific and syn-diastereoselective (Eq. 8.92).232... 

U.S. Environmental Protection Agency (USEPA). 1975. Preliminary investigation of effects on the environment of boron, indium, nickel, selenium, tin, vanadium and their compounds. Volume III. Nickel. U.S. Environ. Protection Agen. Rep. 560/2-75-005c. 89 pp. 

Anonymous. 1975. Preliminary Investigation of Effects on the Environment of Boron, Indium, Nickel, Selenium, Tin, Vanadium and Their Compounds. Vol. IV. Selenium. U.S. Environ. Protection Agency Rep. 560/2-75-005d. Available as PB — 245 987 from Nat. Tech. Inform. Serv., U.S. Dept. Commerce, Springfield, VA. 92 pp. 

Allylation.2 Indium also effects addition of allyl halides to carbonyl compounds under mild conditions. 

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