Edge‐sharing SiN₄ Tetrahedra in the Highly Condensed Nitridosilicate BaSi₇N₁₀

Abstract

The novel nitridosilicate BaSi7 N10 was obtained by the reaction of barium metal with Si(NH)2 in a special high-frequency furnace at 1650 °C. The single-crystal structure determination (a = 687.29(3), b = 671.29(3), c = 963.28(4) pm, β = 106.269(3)°, PC, Z = 2, R1 = 0.0497, wR2 = 0.0924) reveals a network structure of connected SiN4 tetrahedra. BaSi7 N10 is the first nitridosilicate with both corner and edge-sharing SiN4 tetrahedra. Unlike the situation in normal oxosilicates, vertex-sharing of SiN4 tetrahedra is not exclusively favored over edge-sharing. With a Si:N molar ratio of 7:10, BaSi7 N10 is the most highly condensed multinary nitridosilicate known and has almost the same degree of condensation as binary Si3 N4 .