High‐Pressure Synthesis of Sc(5)P(12)N(23)O(3) and Ti(5)P(12)N(24)O(2) by Activation of the Binary Nitrides ScN and TiN with NH(4)F

Multinary transition metal nitrides and oxonitrides are a versatile and intriguing class of compounds. However, they have been investigated far less than pure oxides. The compounds Sc(5)P(12)N(23)O(3) and Ti(5)P(12)N(24)O(2) have now been synthesized from the binary nitrides ScN and TiN, respectively, by following a high‐pressure high‐temperature approach at 8 GPa and 1400 °C. NH(4)F acts as a mineralizing agent that supports product formation and crystallization. The starting materials ScN and TiN are seemingly an uncommon choice because of their chemical inertness but, nevertheless, react under these conditions. Sc(5)P(12)N(23)O(3) and Ti(5)P(12)N(24)O(2) crystallize isotypically with Ti(5)B(12)O(26), consisting of solely vertex‐sharing P(O/N)(4) tetrahedra forming two independent interpenetrating diamond‐like nets that host TM(O/N)(6) (TM=Sc, Ti) octahedra. Ti(5)P(12)N(24)O(2) is a mixed‐valence compound and shows ordering of Ti(3+) and Ti(4+) ions.