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.[2] 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.[3] A synthesis has been reported using an electrochemical cell in a mixed methanol-benzene solution.[4]
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,[5] a structure akin to that seen in YCl3.[6] In contrast, GaCl3 crystallizes as dimers containing Ga2Cl6.[6] Molten InCl3 conducts electricity,[5] whereas AlCl3 does not as it converts to the molecular dimer, Al2Cl6.[7]
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−.[5]
In diethyl ether solution, InCl3 reacts with lithium hydride, LiH, to form . This unstable compound decomposes below 0 °C,[8] and is reacted in situ in organic synthesis as a reducing agent[9] and to prepare tertiary amine and phosphine complexes of InH3.[10]
^Araki, S.; Hirashita, T. "Indium trichloride" in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. doi:10.1002/047084289X.
^Anthony John Downs (1993). Chemistry of aluminium, gallium, indium, and thallium. Springer. ISBN0-7514-0103-X.
^Main Group Metals in Organic Synthesis vol 1, ed. Hisashi Yamamoto, Koichiro Oshima, Wiley VCH, 2004, ISBN3527305084
^The Group 13 Metals Aluminium, Gallium, Indium and Thallium: Chemical Patterns and Peculiarities, Simon Aldridge, Anthony J. Downs, Wiley, 2011, ISBN978-0-470-68191-6
^Main Group compounds in Inorganic Syntheses, vol 31, By Schultz, Neumayer, Marks; Ed., Alan H. Cowley, John Wiley & Sons, Inc., 1997, ISBN0471152889