Das reduzierte Nitridosilicat BaSi 6 N 8

The Reduced Nitridosilicate BaSi 6 N 8 The reduced nitridosilicate BaSi 6 N 8 has been synthesized starting from barium nitride and silicon diimide in a radio‐frequency furnace at temperatures of about 1650 °C. The structure has been determined from X‐ray powder diffraction data and was refined by the Rietveld method ( Imm 2 (no. 44), a = 793.16(1), b = 934.37(2), c = 483.57(1) pm, V = 358.38(1) ·10 6 pm 3 , Z = 2, wR p = 0.0353, R p = 0.0238, R F 2 = 0.0660, 452 observed reflections, 42 parameters). BaSi 6 N 8 crystallizes isotypically with SrSi 6 N 8 . The three‐dimensional Si‐N‐network consists of corner‐sharing SiN 4 tetrahedra and single bonds Si‐Si forming N 3 Si‐SiN 3 building units. 29 Si solid‐state NMR spectra of BaSi 6 N 8 resemble those of SrSi 6 N 8 exhibiting two resonances at δ = −54.3 and −28.0 ppm. Their observed intensity ratio of approximately 2 : 1 can be attributed to the S iN 4 tetrahedra and the S i 2 N 6 units, respectively. This observation is in accordance with the results from the X‐ray structure determination (Si at Wyckoff positions 8 e ( S iN 4 ) and 4 d ( Si 2 N 6 )).