Английская Википедия:Indium(III) chloride
Indium(III) chloride is the chemical compound with the formula InCl3 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.[1] 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.[2] A synthesis has been reported using an electrochemical cell in a mixed methanol-benzene solution.[3]
Like AlCl3 and TlCl3, InCl3 crystallizes as a layered structure consisting of a close-packed chloride arrangement containing layers of octahedrally coordinated In(III) centers,[4] a structure akin to that seen in YCl3.[5] In contrast, GaCl3 crystallizes as dimers containing Ga2Cl6.[5] Molten InCl3 conducts electricity,[4] whereas AlCl3 does not as it converts to the molecular dimer, Al2Cl6.[6]
Reactions
InCl3 is a Lewis acid and forms complexes with donor ligands, L, InCl3L, InCl3L2, InCl3L3. For example, with the chloride ion it forms tetrahedral InCl4−, trigonal bipyramidal InCl52−, and octahedral InCl63−.[4]
In diethyl ether solution, InCl3 reacts with lithium hydride, LiH, to form <chem>LiInH4</chem>. This unstable compound decomposes below 0 °C,[7] and is reacted in situ in organic synthesis as a reducing agent[8] and to prepare tertiary amine and phosphine complexes of InH3.[9]
Trimethylindium, InMe3, can be produced by reacting InCl3 in diethyl ether solution either with the Grignard reagent <chem>MeMgI</chem> or methyllithium, LiMe. Triethylindium can be prepared in a similar fashion but with the grignard reagent EtMgBr.[10]
- <chem>{InCl3} + 3LiMe -> {Me3In.OEt2} + 3LiCl</chem>
- <chem>{InCl3} + 3MeMgI -> {Me3In.OEt2} + 3MgClI</chem>
- <chem>{InCl3} + 3EtMgBr -> {Et3In.OEt2} + 3MgBr2</chem>
InCl3 reacts with indium metal at high temperature to form the lower valent indium chlorides In5Cl9, In2Cl3 and InCl.[4]
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,[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.
References
Шаблон:Indium compounds Шаблон:Chlorides
- ↑ Araki, S.; Hirashita, T. "Indium trichloride" in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. Шаблон:Doi.
- ↑ Indium Trichloride
- ↑ Habeeb, J. J.; Tuck, D. G. "Electrochemical Synthesis of Indium(III) Complexes" Inorganic Syntheses, 1979, volume XIX, Шаблон:ISBN
- ↑ 4,0 4,1 4,2 4,3 Egon Wiberg, Arnold Frederick Holleman (2001) Inorganic Chemistry, Elsevier Шаблон:ISBN
- ↑ 5,0 5,1 Wells, A.F. Structural Inorganic Chemistry, Oxford: Clarendon Press, 1984. Шаблон:ISBN.
- ↑ Шаблон:Greenwood&Earnshaw
- ↑ Шаблон:Cite book
- ↑ Main Group Metals in Organic Synthesis vol 1, ed. Hisashi Yamamoto, Koichiro Oshima, Wiley VCH, 2004, Шаблон:ISBN
- ↑ The Group 13 Metals Aluminium, Gallium, Indium and Thallium: Chemical Patterns and Peculiarities, Simon Aldridge, Anthony J. Downs, Wiley, 2011, Шаблон:ISBN
- ↑ Main Group compounds in Inorganic Syntheses, vol 31, By Schultz, Neumayer, Marks; Ed., Alan H. Cowley, John Wiley & Sons, Inc., 1997, Шаблон:ISBN
- ↑ 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 Шаблон:Doi
