Indium complexes perchlorates

Chapman, C. J., Rrost, C. G., Hartley, J. R, and Whittle, A. J. 2001. Efficient aromatic and heteroatom acylations using catalytic indium complexes with lithium perchlorate. Tetrahedron Lett. 42 773-775. 

Reagents. Aqueous solutions of silver(I) and divalent transition metal perchlorate were used for investigating the structures of the hydrated metal ions(l-4). Copper sulfate(l,2), zinc sulfate(l) and silver(I) nitrate(3) were also used in the structural studies of the aqua metal complexes. A small amount of acid was added to the solutions to prevent hydrolysis of the metal ions. Indium(III) perchlorate was used for the study of the structural determination of the aqua indium(III) complex(5), but no further investigation has been carried out for other complexes except the hexachloroindate complex(6), for which we will not describe here. 

The earlier discussion of complexes of indium(III) with nitrogen ligands emphasized the importance of six-coordination, and in keeping with this, XH and U5In NMR studies have identified [In(H20)6]3+ as the cation in aqueous solutions of perchloric acid.103,104 Confirmatory evidence has been obtained from dilatometric105 and X-ray diffraction106 methods. Proton... 

The weak complexing of indium(III) with chlorate, bromate and iodate has been studied, and stability constants reported, but no preparative work has been done. Perchlorate ion does not complex with indium(III).9... 

The electrochemical procedure for the synthesis of the complex was similar to those described by Tuck [559]. The cell was a 100-cm3 tail-form beaker fitted with a rubber bung through which the electrochemical leads enter the cell. The indium anode was suspended from a platinum wire and the cathode was a platinum wire. [(pySe)2] (0.31 g) was dissolved in acetonitrile and a small amount of tetraethylammonium perchlorate was added to the solution as a current carrier. An applied voltage of 10 V produced a current of 15 mA. During the electrolysis nitrogen gas was bubbled through the solution to provide an inert atmosphere and also to stir the solution phase. After 1 hr of reaction 70 mg of metal had been dissolved from the anode (Ey = 1.1). 

The analysis of solution diffraction data for these systems can be illustrated by results for indium(III) in aqueous perchlorate solutions (211). The RDFs for two concentrated solutions ( 4 M), one slightly acid containing no hydrolysis complexes and one with hydrogen ions removed, each normalized to a stoichiometric unit of volume containing one In atom, are compared in Fig. 28. The major difference between... 

Cationic indium(III) complexes could not be prepared with pyridine, but species such as [In(bipy)3] " and [In(phen)3] are known as the perchlorate or nitrate salts, and [In(terpy)2](C104)3 has also been reported. Stability constants have been measured in the In /bipy and In " /phen systems and for some substituted pyridines. The adducts of indium(III) halides and pseudohalides with pyridine and substituted pyridines have been... 

New catalysts have heen recently developed for promoting the aldol-type addition of acetate-derived silyl ketene acetals with high efficiency 10-methylacridinium perchlorate (5 mol %), cationic mono- and dinuclear iron complexes (5 mol %), t-hutyldimethylsilyl chloride-indium(III) chloride (10 mol %), [l,2-henzenediolato(2—)-0,0 ]oxotitanium(20 mol%), phos-phonium salts (7 mol%), and trityl salts (5-20 mol%). ... 

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