INDIUM(III) AMIDES AND NITRIDES

Indium amide (In(NH2)s) was synthesized from a reaction between InI3 and 3 equiv of KNH2 in anhydrous liquid ammonia at 25 degrees C. The white solid is nearly insoluble in ammonia but dissolves in NH3 solutions of KNH2 to form potassium indium amides, KxIn(NH2)(3+x). Sodium indium amides can be obtained similarly. A reaction between InI3, 3 equiv of LiI, and 6 equiv of KNH2 affords Li3In(NH2)(6), which is insoluble in ammonia. Indium nitride is obtained from the thermolysis of In(NH2)(3), NaxIn(NH2)(3+x), and KxIn(NH2)(3+x). Reduction to indium metal also occurs during thermal decomposition of some of the potassium indium amides. Thermolysis of Li3In(NH2)(6) affords the new ternary nitride Li3InN2, an orange, water-sensitive electrical insulator, whose powder pattern was indexed to a cubic primitive cell of a = 10.136(8) Angstrom. Direct reaction between Li3N and InN produces InLi in addition to Li3InN2, and thus is not a viable synthesis route to this new nitride.