Indium(III) chloride is the chemical compound with the formula which forms a tetrahydrate. This salt is a white, flaky solid with applications in organic synthesis as a Lewis acid. It is also the most available soluble derivative of indium.Araki, S.; Hirashita, T. "Indium trichloride" in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. . This is one of three known indium chlorides.
Synthesis and structure Being a relatively electropositive metal, indium reacts quickly with chlorine to give the trichloride. Indium trichloride is very soluble and deliquescent. A synthesis has been reported using an electrochemical cell in a mixed methanol-benzene solution.Habeeb, J. J.; Tuck, D. G. "Electrochemical Synthesis of Indium(III) Complexes" Inorganic Syntheses, 1979, volume XIX,
Like and , crystallizes as a layered structure consisting of a close-packed chloride arrangement containing layers of octahedrally coordinated In(III) centers,Egon Wiberg, Arnold Frederick Holleman (2001) Inorganic Chemistry, Elsevier a structure akin to that seen in .Wells, A.F. Structural Inorganic Chemistry, Oxford: Clarendon Press, 1984. . In contrast, crystallizes as dimers containing . Molten conducts electricity, whereas does not as it converts to the molecular dimer, .
The tetrahydrate, InCl3·4H2O, crystallises in the orthorhombic crystal system. It consists of a unit of [InCl3(H2O)2] interconnected by two water of crystallizations. It is produced by the evaporation of a solution of indium(III) chloride.
Reactions is a Lewis acid and forms complexes with donor ligands, L, , , . For example, with the chloride ion it forms tetrahedral , trigonal bipyramidal , and octahedral .
In diethyl ether solution, reacts with lithium hydride, LiH, to form lithium tetrahydroindate(III) . This unstable compound decomposes below 0 °C, and is reacted in situ in organic synthesis as a reducing agentMain Group Metals in Organic Synthesis vol 1, ed. Hisashi Yamamoto, Koichiro Oshima, Wiley VCH, 2004, and to prepare tertiary amine and phosphine complexes of .The Group 13 Metals Aluminium, Gallium, Indium and Thallium: Chemical Patterns and Peculiarities, Simon Aldridge, Anthony J. Downs, Wiley, 2011,
Trimethylindium, , can be produced by reacting in diethyl ether solution either with the Grignard reagent methylmagnesium iodide or methyllithium . Triethylindium can be prepared in a similar fashion but with the grignard reagent EtMgBr.Main Group compounds in Inorganic Syntheses, vol 31, By Schultz, Neumayer, Marks; Ed., Alan H. Cowley, John Wiley & Sons, Inc., 1997,
reacts with indium metal at high temperature to form the lower valent indium chlorides , and InCl.
Catalyst in chemistry Indium chloride is a Lewis acid catalyst in organic reactions such as Friedel-Crafts acylations and Diels-Alder reactions. As an example of the latter,An efficient synthesis of novel pyrano[2,3-d]- and furopyrano[2,3-d]pyrimidines via Indium-Catalyzed Multicomponent Domino Reaction Prajapati, D. Mukut Gohain, M. Beilstein Journal of Organic Chemistry 2006, 2:11 the reaction proceeds at room temperature, with 1 mole% catalyst loading in an acetonitrile-water solvent mixture. The first step is a Knoevenagel condensation between the barbituric acid and the aldehyde; the second step is a reverse electron-demand Diels-Alder reaction, which is a multicomponent reaction of N,N'-dimethyl-barbituric acid, benzaldehyde and ethyl vinyl ether. With the catalyst, the reported chemical yield is 90% and the percentage trans isomer is 70%. Without the catalyst added, the yield drops to 65% with 50% trans product.
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