The synthesis of Cs2Au2Cd2S4, Rb2Au2Cd2S4, and K2Au4CdS4 in reactive A2S(r) (A=K, Rb, Cs) fluxes at 550°C is reported. Cs2Au2Cd2S4 crystallizes in space group Cmma (no. 67), with a=6.5833(9), b= 14.055(3), c=6.0369(8) Å, Z=2, ρ(calcd)=6.02 gcm-3, μ((Moka))=368.96 cm-1, 2Θ(max)=80°, reflections with F0/2> 3σ(F0/2)=473, R = 0.036, R(w)=0.039. Rb2Au2Cd2S4 crystallizes in space group Pcca (no. 54), with a=13.930(8), b=5.757(3), c=6.742(1) Å, Z=2, P(calcd)= 5.64 gcm-3, μ((MoKa))=402.31 cm-1, 2Θ(max)=50°, reflections with F0/2> 3σ(F0/2)=179, R=0.063, R(w)=0.071. K2Au4CdS4 crystallizes in the space group Ibam (no. 72), with a=10.568(3), b=6.973(2), c=14.690(5) Å, Z=4; P(calcd)=6.79 g cm-3; μ((MoKa))=572.44 cm-1; 2Θ(max)=70°; reflections with F0/2> 3σ(F0/2)=335, R=0.052, R(w)=0.054. Cs2Au2Cd2S4, and Rb2Au2Cd2S4 are new layered compounds which feature the linear [Cd2S4](n)/(4n-) fragment, connected in layers by linearly coordinated Au atoms. K2Au4CdS4 is assembled from single [CdS4]6- tetrahedra which are arranged in a rectangular lattice and linked by four linearly coordinated gold(I) atoms. There are two sets of one-dimensional (AuS)(n)/(n-) chains in K2Au4CdS4, running in the (110) and (-110) directions and stitched together with tetrahedrally coordinated Cd atoms. The A2Au2CD2S4 compounds and K2Au4CDS4 are wide band-gap semiconductors and photoluminescence strongly. The optical absorption and photoluminescence properties are reported.
|Original language||English (US)|
|Number of pages||7|
|Journal||Chemistry - A European Journal|
|State||Published - Jan 1 1998|
- Solid-state structures
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