7791-29-9Relevant academic research and scientific papers
Synthesis, properties, and structure of LiAuI4 and KAuI4 with a discussion of the crystal chemical relationship between the halogenoaurates RbAuCl4, AgAuCl4, RbAuBr4 and LiAuI4
Lang, E. Schulz,Abram,Str?hle
, p. 1791 - 1795 (2008/10/09)
The alkalimetal iodo aurates(III) MAuI4 (M = Li, K) are obtained in form of single crystals from MI, Au and I2 in a sealed glass ampoule by heating to 550°C and slow cooling to 300°C. KAuI4 crystallizes in the monoclinic space group P21/c with a = 968.6(4); b = 704.5(2), c = 1393.2(7) pm; β = 100.95(2)° and Z = 4. The crystal structure is built up from square planar AuI4- anions and K+ cations. The cations are coordinated by eight I atoms of neighbouring AuI4- anions with distances K-I between 350.0 and 369.6 pm. At 100°C KAuI4 is reduced to form K3Au3I8, which at 180°C decomposes to KI, Au and I2. LiAuI4 forms black, moisture sensitive needles, decomposing in the absence of iodine at 20°C to LiI, Au and I2. It crystallizes in a variant of the RbAuBr4 type structure with the space group P21/a and a = 1511.7(4); b = 433.9(4); c = 710.0(2) pm; β = 121.50(2)°; Z = 2. The crystal chemical relationship between the structures of RbAuCl4, RbAuBr4, AgAuCl4 and LiAuI4 is discussed.
