Synthesis and Structure of Sr3GaN3 and Sr6GaN5: Strontium Gallium Nitrides with Isolated Planar [GaN3]6- Anions

Two new strontium gallium nitrides were obtained as single crystals by reaction in molten Na. Black SrsGaNs is isostructurat with its transition metal analogues, Sr3MnN3, Ba3MnNs, SrsCrNs, BasCrNs, and BasFeNs, and is the first example of a 313-ternary nitride containing only main group metals. It crystallizes in space group PGa/m (No. 176) with a = 7.584(2) A, c = 5.410(3) A, and Z= 2. Black SreGaNs is isostructural with CaeGaNs and also with its transition metal analogues, Ca6MnN5 and Ca6FeN5. It crystallizes in space group PQmcm (No. 193) with a = 6.6667(6) A, c= 12.9999(17) A, and Z= 2. Both Ga compounds contain isolated planar [GaNs] nitridometallate anions of D symmetry.