Indium complexes halogens

Metal-halogen stretching vibrations in coordination complexes of gallium, indium and thallium. A. J. Carty, Coord. Chem. Rev., 1969,4, 29-39 (32). 

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. 

Indium (I) halides insert into nickel halogen bonds of carbonyl group free organonickel complexes to form Ni-In bond compounds, which can be viewed as derivatives of trimethylindium or indiumtrihalides. ... 

Other o-bonded metal porphyrins have electronic absorption spectra belonging to the hyperclass. The o-bonded complexes of iron , indium gallium exhibit such typical spectra. Thus, replacement of the anionic axial ligand on the halogenated complexes M(Por)X by an alkyl (or aryl) o-bonded ligand results in a splitting of the Soret band into two bands. One of the bands is red shifted and the other is blue shifted with respect to the same porphyrin complex with anionic axial ligands. This is illustrated in Fig. 2 for In(OEP)Cl and In(OEP)(C(CH3)3). 

Electronic spectra of the sulfinato and sulfonato complexes are similar to those of other high-spin iron(III) porphyrins and belong to the hyper class 0. The morphology of the NMR spectra and the chemical shifts of the indium and gallium sulfinato or sulfonato porphyrins are nearly identical to those for the halogenated derivatives ... 

In chemical shifts in n.m.r. spectra of In-halogen complexes have been measured in solution. They fall in the following sequence InCl < InBr < [In(H20)e] + < Inl. In linewidths are largely determined by quadrupole relaxation, and they may be used to study the symmetry of the complexes. Indium, when extracted into organic solvents from aqueous HCl, HBr, or HI solutions, exists as tetrahedral species, although the existence... 

Supramolecular self-organization, with different amounts of complexity based upon dative bonds (see Section 3.2.3.1) and secondary bonds, is observed for organoindium halides. Long indium-halogen interatomic distances (although shorter than the expected van der Waals distance (ca. 3.8 A for In- -Cl)) are observed for most structurally characterized organoindium halides. 

Most of indium triflate s apphcations exploit its properties as a mild, chemoselective, and versatile Lewis acid. It has been shown to activate various functional groups containing oxygen, halogens, or carbon-carbon u--bonds, enhancing the electrophilicity or nu-cleophUicity of the complexed species. 

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