Lithium metal nitrogen

Lithium Nitride. Lithium nitride [26134-62-3], Li N, is prepared from the strongly exothermic direct reaction of lithium and nitrogen. The reaction proceeds to completion even when the temperature is kept below the melting point of lithium metal. The lithium ion is extremely mobile in the hexagonal lattice resulting in one of the highest known soHd ionic conductivities. Lithium nitride in combination with other compounds is used as a catalyst for the conversion of hexagonal boron nitride to the cubic form. The properties of lithium nitride have been extensively reviewed (66). 

As soon as the receiver containing the methyl 11 thiurn solution has been removed and stoppered, the residual solids in the reaction flask and the filtration apparatus should be rinsed Into another receiver with anhydrous ether under an atmosphere of argon or nitrogen. The ether slurry of solids, which may contain some unchanged lithium metal, should be treated cautiously in a hood with t-butyl alcohol to consume any residual lithium metal before the mixture is discarded. 

In a related reaction, heating ketones in the presence of TlClsOTf leads to 1,3,5-trisubstituted arenes. " Nitriles react with 2 mol of acetylene, in the presence of a cobalt catalyst, to give 2-substituted pyridines. " Triketones fix nitrogen gas in the presence of TiCU and lithium metal to form bicyclic pyrrole derivatives. " ... 

C04-0018. Lithium metal is one of the few substances that reacts directly with molecular nitrogen ... 

Li + N2 2 Li3 N What mass of the product, lithium nitride, can be prepared from 4.5 g of lithium metal and 9.5 g of molecular nitrogen ... 

A remarkable process was reported by Mori that forms aniline from dinitrogen (Equation (26)).106 Titanium nitrogen fixation complexes were generated from reactions of titanium tetrachloride or tetraisopropoxide, lithium metal, TMS chloride, and dinitrogen. These complexes generated a mixture of aryl and diarylamines in yields as high as 80% when treated with aryl halide and a palladium catalyst containing DPPF ... 

Styrene, benzene, and tetrahydrofuran were purified as described previously (8,11). Solutions of ec-butyllithium (Lithium Corporation of America, 12.0 wt % in cyclohexane) and methyllithium (Alfa, 1.45 M in ether) and lithium naphthalene were analyzed using the double titration procedure with 1,2-dibromoethane (12). Lithium naphthalene was prepared in tetrahydrofuran from lithium metal and a 25 mole % excess of sublimed naphthalene at -25°C using standard high vacuum procedures. Sealed ampoules of lithium naphthalene were stored in liquid nitrogen. 

Lithium nitride is prepared by passing dry nitrogen gas over lithium metal 6Li -I- N2 —> 2Li3N... 

The use of lithium amides to metalate the a-position of the N-substituent of imines generates 2-azaallyl anions, typically stabilized by two or three aryl groups (Scheme 11.2) (48-62), a process pioneered by Kauffmann in 1970 (49). Although these reactive anionic species may be regarded as N-lithiated azomethine ylides if the lithium metal is covalently bonded to the imine nitrogen, they have consistently been discussed as 2-azaallyl anions. Their cyclization reactions are characterized by their enhanced reactivity toward relatively unactivated alkenes such as ethene, styrenes, stilbenes, acenaphtylene, 1,3-butadienes, diphenylacetylene, and related derivatives. Accordingly, these cycloaddition reactions are called anionic [3+2] cycloadditions. Reactions with the electron-poor alkenes are rare (54,57). Such reactivity makes a striking contrast with that of N-metalated azomethine ylides, which will be discussed below (Section 11.1.4). 

Preparation of Lithium Nitride by Reacting Lithium with Nitrogen. Assemble an apparatus as shown in Fig. 83. Insert an iron tube into quartz tube 9. Using pincers, extract a small piece of metallic lithium from the kerosene in which it is stored (wear eye protection ), put it in a mortar, and carefully remove the solid crust covering the surface of the metal from all its sides with a thin knife. Lower the cleaned piece of lithium for two or three seconds into a beaker with methanol (why ) and put it into an iron boat. Put the latter into the iron tube. 

H.3 Write balanced chemical equations for the following reactions (a) Sodium metal reacts with water to produce hydrogen gas and sodium hydroxide, (b) The reaction of sodium oxide, Na20, and water produces sodium hydroxide, (c) Hot lithium metal reacts in a nitrogen atmosphere to produce lithium nitride, Li3N. (d) The reaction of calcium metal with water leads to the evolution of hydrogen gas and the formation of calcium hydroxide, Ca(OH)2. 

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... 

A. Lithium 2,6-dimetkylpkenoxide. In a 300-ml. flask, equipped with a magnetic stirrer and a reflux condenser and flushed with nitrogen, are placed 150 ml. of toluene (freshly distilled from sodium), 1.40 g. (0.202 mole) of lithium metal (Note 1) and 25.0 g. (0.205 mole) of resublimed 2,6-dimethylphenol. The mixture... 

A similar reaction takes place between lithium and nitrogen gas to form lithium nitride, Li3N, but the other alkali metals do not react with nitrogen. 

Octamethylcyclotetrasilazane (130) reacts with M-butyllithium or alkaline metals to give the alkali salts, which crystallize as dimeric THF adducts (equation 40). In the dimers, two eight-membered rings are connected by a planar alkali metal-nitrogen four-membered ring. Lithium is tricoordinated, sodium tetracoordinated and potassium penta- and hex-acoordinated. The coordinatively bonded THF in the lithium compound (131) can be exchanged with the Lewis base TMEDA103. 

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