Formation of transition-metal nitrides from the reactions of lithium amides and anhydrous transition-metal chlorides

Abstract

Reaction of anhydrous metal chlorides and lithium amide at 160–400 °C induces an exothermic reaction with formation of lithium chloride and an amorphous material. Trituration of the product with tetrahydrofuran (THF) followed by thermolysis at 700 °C for 1–2 h results in the formation of crystalline metal nitrides of varying composition (TiN, ZrN, HfN, VN, NbN, TaN, Cr₂N, CrN, Mo₂N, W₂N, Mn₃N₂ and Zn₃N₂). Reactions involving iron, nickel, copper and indium chlorides with lithium amide yielded the metallic elements. The reactions of lithium dimethylamide and lithium diisopropyl amide and selected metal chlorides also produced metal nitrides under comparable reaction conditions. The metal nitrides were analysed by powder XRD, microanalysis, magnetic moment measurements, FTIR and SEM/EDXA.