infinity(1)[Sn-3/3] tubes and AuSn3 building units: Synthesis and crystal structure of Na2AuSn3 [German]

摘要

Silver coloured, brittle single crystals of the metallic conducting compound Na2AuSn3 were synthesized by reaction of sodium azide with gold sponge and tin powder at T = 820 K. The structure of the new compound (space group P6(3)/mmc, Z = 4, a = 9.585(1) Angstrom, c = 7.516(2) Angstrom) was determined from X-ray single-crystal diffractometry data. Na2AuSn3 crystallizes in a ternary variant (Lu2CoGa3 type) of the AlB2 type. The tin atoms form the motif of a (1)(infinity)[Sn-3/3] tubular fragment of the hexagonal diamond structure. The (1)(infinity)[Sn-3/3] tubes are connected to a framework structure via gold atoms with a trigonal planar tin coordination. The sodium atoms are placed in channel-like cavities of the Au-Sn partial structure. [References: 22]