SODIUM NITRIDO METALLATES, NA3MN3, OF MOLYBDENUM(VI) AND TUNGSTEN(VI) WITH [CRO2O2/2] ISOSTERIC [MON2N2/2]3-CHAINS

Molybdenum as well as tungsten powder react with an excess of NaNH2 in autoclaves in a temperature range of 450-600-degrees-C to sodium nitrido metallates(VI), Na3MN3. Na3MoN3 forms dark-red transparent crystals. Its structure was determinated from X-ray single crystal data: space group Cc, Z = 8, a = 13.854(5) angstrom, b = 10.889(2) angstrom, c = 6.366(2) angstrom, beta = 117.23(3)-degrees, R/R(w) = 0.065/0.072 with N(F(o)2) greater-than-or-equal-to 3sigma(F(o)2) = 1745, N(var) = 68 Na3MoN3 contains chains of corner-sharing [MoN2N2/2]-tetrahedra in accordance with the extended Zintl-Klemm principle. Na3WN3 powder is yellow and Guinier data revealed an isotypic structure to the molybdenum compound: space group Cc, Z = 8, a = 13.777(3) angstrom, b = 10.999(2) angstrom, c = 6.401(2) angstrom, beta = 117.18(2)-degrees.