Production of cis-Na2N2O2 and NaNO3 by Ball Milling Na2O and N2O in Alkali Metal Halide Salts.

Ball milling of sodium oxides and alkali metal halide salts under a pressure of 2 atm nitrous oxide at temperatures of 38 ± 4 °C is reported. After 2.5 h of ball milling, FTIR data for both 14N2O and 15N2O additions show conclusively that cis-Na2N2O2 is formed based on excellent agreement with data reported earlier by Jansen and Feldmann who prepared pure crystalline cis-Na2N2O2 by reaction of sodium oxide and nitrous oxide for 2 h at 360 °C in a tube furnace. Continued ball milling under nitrous oxide leads to slow buildup of NaNO3 with yields on the order of 24% achieved in 20 h. Production of nitrate only occurs during active ball milling. Studies over the first 10 h reveal a trend among potassium halide salts: KBr ≅ KCl > KI ≫ KF. Ball milling of sodium oxide alone under an atmosphere of N2O gives much lower yields than ball milling in the presence of added alkali metal halide salt. Ball milling of sodium oxide and nitrous oxide in fluorocarbon oil, silicone oil, calcium fluoride, clinoptilolite, molecular sieves, and silica gel does not lead to significant yields of either cis-Na2N2O2 or NaNO3.