Coordination Complexes of Indium and 2,2',2'-Terpyridyl and of Indium and 5-Nitro-1,10-phenanthrolin

Indium ions react with 2,2?,2"-terpyridyl in dilute alcohol or in aqueous solution forming bisterpyridyl indium salts, of which the chloride, bromide, iodide, and thiocyanate are insoluble. As thiocyanate, one part of indium per lo5 may be detected. Metals such as zinc, tin, and iron, with which indium is usually associated, interfere with the reaction. With 5-nitro-1,lO-phenanthroline, indium forms insoluble tris-(5-nitro-1,10-phenanthroline) indium salts as chloride, bromide, iodide, and thiocyanate. The reactions are of little value since the least soluble salt, the iodide, is 0.04 per cent. soluble.