Potassium nitride is an unstable chemical compound. Several syntheses were erroneously claimed in the 19th century, and by 1894 it was assumed that it did not exist.[2]
However, a synthesis of this compound was claimed in 2004. It is observed to have the anti-TiI 3 structure below 233 K (−40 °C; −40 °F), although a Li 3P-type structure should be more stable. Above this temperature, it converts to an orthorhombic phase. This compound was produced by the reaction of potassium metal and liquid nitrogen at 77 K (−196.2 °C; −321.1 °F) under vacuum:[1]
6K + N2 → 2K3N
This compound decomposes back into potassium and nitrogen at room temperature.
^ abFischer, D.; Cancarevic, Z.; Schön, J. C.; Jansen, M. (January 2004). "Zur Synthese und Struktur von K3N". Zeitschrift für anorganische und allgemeine Chemie (in German). 630 (1): 156–160. doi:10.1002/zaac.200300280.