Alkaline earth metals reaction with nitrogen

Tin-nitrogen bonded compounds are generally formed by reaction of an alkali or alkaline earth metal amide with an organotin halide compoundsofthe types R Sn(NR2)4- , ( = 1-3), (R3Sn) NR (n = 1-3), andcyc/o-(R2SnNR0 ( = 2 or 3) can be prepared (equation 79). Other routes include transaminations (equations 80 and 81). Tin carboxamides and snlfonamides have been obtained by reaction of tin oxides or hydroxides with amides (equation 82). 

Sr2Si5Ng, Ba2Si5Ng and Ca2Si5Ng were synthesized by the reaction of silicon diimide with alkaline earth metals under a nitrogen atmosphere, and subsequently characterized [271-273]. 

Another example of the combined effect of nitrogen oxides and a heterogeneous catalyst in the oxidation of methane at atmospheric pressure is given in [188]. In this paper, the authors demonstrated that, by using MgO and CaO, alkaline-earth metal oxides with a high adsorption capacity with respect to OH radicals, as catalysts, it is possible to increase the yield of Ci-oxygenates in the NOx-promoted process by 10%, evidently due to a decrease in the rate of consumption of formed oxygenates in reactions with radicals. 

As already known (Addison Logan 1964), anhydrous nitrates exhibit oxidizing properties. Their oxidizing activity increases from ionic nitrates with alkali and alkaline earth metal cations to covalent nitrates with transient metal cations. Oxidation reactions result in the formation of nitrogen-containing oxides. Depending on the kind of nitrate salt and on the reaction conditions, one of these oxides can be predominant. Organic substrates can evidently serve as reductant. 

The alkali metals and alkaline earth metals are reactive toward most nonmetallic elements. Accordingly, they react with nitrogen, phosphorus, and arsenic to give binary compounds, but only those of nitrogen and phosphorus will be considered here. The reactions occur when the two elements are heated together as shown in the following equations ... 

While the latter reactions are no longer used for nitrogen fixation, the reaction of dinitrogen with dihydrogen to form ammonia is among the most important industrial processes. The alkaline-earth metals react readily with dinitrogen at elevated temperatures to form nitrides lithium reacts even at room temperature with dinitrogen. 

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