Indium isolation

Coordination Compounds. A large number of indium complexes with nitrogen ligands have been isolated, particularly where Ir is in the +3 oxidation state. Examples of ammine complexes include pr(NH3)3] " [24669-15-6], prCl(NH3)] " [29589-09-1], and / j -pr(03SCF3)2(en)2]" [90065-94-4], Compounds of A/-heterocychc ligands include trans- [xCX py)][ [24952-67-8], Pr(bipy)3] " [16788-86-6], and an unusual C-metalated bipyridine complex, Pr(bipy)2(C, N-bipy)] [87137-18-6]. Isolation of this latter complex produced some confusion regarding the chemical and physical properties of Pr(bipy)3]3+ (167). 

The synthesis and characterization of the monomeric amidinato-indium(I) and thallium(I) complexes [Bu C(NAr)2]M[But(NAr(NHAr)] (M = In, Tl Ar = 2,6-Pr2CgH3) have been reported. Both compounds were isolated as pale yellow crystals in 72-74% yield. These complexes, in which the metal center is chelated by the amidinate ligand in an N, j -arene-fashion (Scheme 33), can be considered as isomers of four-membered Group 13 metal(I) carbene analogs. Theoretical studies have compared the relative energies of both isomeric forms of a model compound, In[HC(NPh)2]. ... 

Indium-mediated allylation of an unreactive halide with an aldehyde132 was used to synthesize an advanced intermediate in the synthesis of antillatoxin,133 a marine cyanobacteria (Lyngbya majus-cula) that is one of the most ichthyotoxic compounds isolated from a marine plant to date. In the presence of a lanthanide triflate, the indium-mediated allylation of Z-2-bromocrotyl chloride and aldehyde in saturated NH4C1 under sonication yielded the desired advanced intermediate as a 1 1 mixture of diastereomers in 70% yield. Loh et al.134 then changed the halide compound to methyl (Z)-2-(bromomethyl)-2-butenoate and coupled it with aldehyde under the same conditions to yield the desired homoallylic alcohol in 80% yield with a high 93 7 syn anti selectivity (Eq. 8.55). 

In synthetic applications, Li et al. examined the propargylation-allenylation of carbonyl compounds by using a variety of metals including Sn, Zn, Bi, Cd, and In.203 By using the indium-mediated allenylation reaction, Li and co-workers developed the synthesis of the antiviral, antitumor compound (+)-goniofufurone (Scheme 8.22),204 a key component isolated from the Asian trees of the genus Goniothalamus,205 and other styryl lactone derivatives (Eq. 8.80). 

Tris(0-ethyl dithiocarbonato)chromium(III) is obtained as a dark blue crystalline powder which decomposes at 100 to 140°. The indium(III) ethylxanthate complex forms small colorless crystals which decompose at 130 to 150°.16,17 The cobalt (III) ethylxanthate complex is isolated as a dark green crystalline powder whose decomposition temperature determined by use of a thermal balance is 135 to 137° (lit. value, 117° 2 118 to 119°8). These compounds decompose slowly in air and more rapidly when heated in solution. The tripositive chromium, indium, and cobalt complexes are insoluble in water but are soluble in many organic solvents (Table T). 

Biscarbene complexes of indium(III) halides can be isolated from the reaction of two equivalents of l,3-diisopropyl-4,5-dimethylimida-... 

A third route to allenyltin halides involves transmetallation of isolable allenyltri-butyltin compounds, as exemplified by the reaction of allenyltributyltin with Bu2SnCl2 [68]. The resulting mixture of allenyl- and propargyldibutyltin chlorides reacts with various aldehydes to afford mixtures of propargyl- and allenylcarbinols (Eqs. 9.78 and 9.79). The yields of these additions are uniformly high, but the selectivity depends on the nature of the aldehyde substituent. The transmetallation route to allenyltin and -indium halides will be discussed in more detail in a later section. 

One of the first published cluster compounds of the heavier group 13 elements was the closo-dodecaaluminate K2[Ali2iBui2] 54 (Figure 2.3-10) [79], which possesses an almost undistorted icosahedron of 12 aluminum atoms with short Al-Al distances (268-270 pm). Up until today, it remained the only homonuclear cluster compound of the elements aluminum to indium which, with respect to structure and cluster electron count, is completely analogous to any boronhydride (see Chapters 1.1.2, 1.1.3, 1.1.5.2, and 2.1.5.6) (in this case doso-[Bi2H12]2 ). Compound 54 was formed in small quantities by the reaction of di(isobutyl)aluminum chloride with potassium and was isolated as dark red crystals (Figure 2.3-10). 

Notes on cluster phases in triel alloys. Li and Corbett (2004) have shortly reviewed the systematic and extensive experimental and theoretical work carried out by Corbett and co-workers (see for instance Corbett 1996). Considering alkali metal-triel alloys, they underlined, particularly for Ga, In and Tl, the richness of their chemistry (see also 5.3.4.4). Gallium forms many anionic network structures (and only a few phases containing isolated cluster units), indium gives several examples of both network and discrete cluster structures, thallium forms especially discrete clusters (Tl , T157A Tl , Tl , Tl(f, Tl ). 

Indium also has many of the characteristics that make Al and Ga very useful for such applications. Particularly important is its capacity to dissolve Si, Ge and several lanthanide and transition metals, producing highly reactive forms of the elements. Moreover In does not form binaries with Si and Ge and has a low-melting point. RNiGe2 compounds, for instance, were prepared from stoichiometric quantities of the components in fine powder mixed with a 10 fold quantity of In in alumina tubes. These, flame sealed in fused silica tubes, were slowly heated to 1000°C, held at this temperature for a few hours, ramped down to 850°C, held for an additional 4 days and finally cooled down to room temperature over the course of another 4 days. Compound isolation from the In excess was performed by centrifugation at 300°C through a coarse frit. Further purification was carried out by a 15-minute submersion and sonication in 6 M aqueous HC1 (Salvador et al. 2004). 

The reaction of toluene solutions of indium trichloride and tris(trimethylsilyl)arsine resulted in the formation of a very fine dark-brown powder subsequently annealed up to 400°C to drive to completion the elimination of trimethyl-silyl-chloride. Nanocrystalline InAs was obtained. Similar reactions with InBr3 and Inl3 and P compounds have been discussed. Previously a similar reaction was described by Uchida et al. (1993) (reaction of indium acetylacetonate with tris(trimethylsilyl)arsine in refluxing triglyme). Subsequently the reaction with InCl3 was used by Guzelian et al. (1996) in the preparation of nano-crystal quantum dots. They compared different preparation methods and techniques useful to isolate specific size distributions. 

As for the synthesis of ort/io-phenylene indium complexes, the transmetallation reactions of organomercurials with indium(I) halides have also been considered for the preparation of 1,8-naphthalenediyl diindium complexes. While the dimercura-cycle 62 fails to react with InBr, l,8-bis(chloromercurio)naphthalene (25) and 1,8-bis(bromomercurio)naphthalene (63) react with their respective indium(I) halides to yield the mercura-indacycles 64 and 65 (Scheme 25) which have been isolated as bis(THF) adducts. The indium center of 65-(THF)2 is penta-coordinated and... 

Indium(III)-NHC complexes have been isolated in the form of their trihydrides... 

The conventional preparative routes to anionic, neutral, or cationic complexes of indium start with the metal, which is dissolved in a suitable mineral acid to give a solution from which hydrated salts can be obtained by evaporation. These hydrates react with a variety of neutral or anionic ligands in nonaqueous solvents, and a wide range of indium(III) complexes have been prepared in this manner.1 Alternatively, the direct high-temperature oxidation of the metal by halogens yields the anhydrous trihalides, which are again convenient starting materials in synthetic work. In the former case, the initial oxidation of the metal is followed by isolation, solution reaction, precipitation, and recrystallization. 

Reich and Richter found that it is easier to isolate it from the zinc than from the original blende. They reduced indium oxide in a current of hydrogen or illuminating gas and melted the metal under potassium cyanide (44, 45). At the suggestion of Ferdinand Reich, Clemens Winkler made a thorough study of the metal and its compounds (20). 

The absorption spectrum of isolated indium spheres differs from that of closely packed oblate spheroids in that the peak shifts from 2230 A to 4100 A about half of this shift is attributable to particle shape and half to particle interaction. Indium particles on immunological slides are not identical, however, but are distributed in size and shape about some mean this tends to broaden the spectrum. 

The isolation of neutral monomeric and stable indium amides in the solid state is only feasible with use of bulky substituents, and the synthesis is usually accomplished by a... 

A series of main-group transition metal clusters of manganese and rhenium with the structural types [37] and [32] has been isolated from reactions of the carbonyls with gallium and indium 201, 202, 323, 324. ... 

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