Lithium transition metal nitrides

Transition-metal nitrides where nitrogen is present as an interstitial are prepared by the reaction of the metals with NH3 around 1470 K. BN is obtained by heating boron with NH3 at white heat. Metal nitrides are also prepared by the reaction of metal chlorides with NHj. For example, MN and WN films are prepared by the reaction of NH3 with AICI3 and WCl respectively. Recently, nitrides of Ti, Zr, Hf and lanthanides have been prepared by the reaction of lithium nitride with the anhydrous metal chlorides [8] ... 

See Lithium nitride Transition metal halides Sulfur nitrides... 

Until recently, the synthesis of ionic/covalent nitrides was relatively unexplored except for the pioneering work of Juza on ternary lithium nitrides.11 However, within the last decade, several groups have begun to explore ternary nitride systems, many of which have relied on the inductive effect. The inductive effect is based on the donation of electron density from an electropositive element to an adjacent metal-nitrogen bond, thereby increasing the covalency and stability of that bond and of the nitride material itself. The success of this method is illustrated by the fact that almost all of the known ionic/covalent ternary nitrides contain electropositive elements. Only recently has a small number of transition metal ternary nitrides been synthesized in the absence of the inductive effect at moderate temperatures, by taking advantage of low temperature techniques, such as the ammonolysis of oxide precursors and metathesis reactions.6,12-17... 

The only reactions of molecular nitrogen at ambient temperature are the formation of lithium nitride Li3N, reactions with certain transition metal complexes, and nitrogen fixation with nitrogenase in the bacteria of the root nodules of legumes and in blue algae (Sections 14.1.1 and 14.1.2). Above 500 °C nitrogen reacts with some elements, especially with metals (nitride formation). 

By far the largest class of ternary lithium nitrides are those with the antifluorite structure, prepared largely by Juza, and reviewed by him [42], The ternaries are more thermally stable than the binaries which would seem to indicate a relaxation of the internal strain (both cation- cation and anion-anion repulsions) of binary nitrides. Many of these compounds are in fact ordered superstructures of antifluorite and it is remarkable that most of the transition metals are observed in high oxidation states--much higher than those in the binaries (e.g. Li7Mn + N4 vs Mn5 + N2). They are Li+ conductors at elevated... 

Alkali oxides are thermodynamically stable up to very high temperatures, and even hydrides have saline character and considerable stability. Lithium nitride is a compound which can be isolated from the solution in the metal in crystalline form. Dissolved oxides have the ability to react with transition metal oxides to form complex oxides, or with hydrogen to form hydroxides of the heavier alkali metals. Lithium cyanamide is formed by means of the reaction between nitrogen and carbon dissolved in the molten metal. The reaction product in liquid sodium is sodium cyanide. 

The nitrogen exchange between lithium and several transition metals gives rise to the formation of binary or ternary nitrides, which show analogies with the ternary oxides formed in Na—O—Me systems . In the lithium-nitrogen-stainless steel system, nitrogen is picked-up by the stainless steel due to the getter reaction of the... 

Besides, using nanomaterials will enable some lithium-storage mechanisms available for mass storage. One such new mechanism is the so-called "conversion" mechanism [32], which is first found in transition metal oxides, then in fluorides, suliides, and nitrides [33, 57, 58], and the mechanisms can described by Eq. 6.4 ... 

These are usually reactions of anhydrous transition and B metal halides with dry alkali metal salts such as the sulphides, nitrides, phosphides, arsenides etc. to give exchange of anions. They tend to be very exothermic with higher valence halides and are frequently initiated by mild warming or grinding. Metathesis is described as a controlled explosion. Mixtures considered in the specific reference above include lithium nitride with tantalum pentachloride, titanium tetrachloride and vanadium tetrachloride, also barium nitride with manganese II iodide, the last reaction photographically illustrated. 

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