Syntheses, structures, and properties of new quaternary gold-chalcogenides:: K2Au2Ge2S6, K2Au2Sn2Se6, and Cs2Au2SnS4

The new compounds K2Au2Ge2S6 (1), K2Au2Sn2Se6 (2), and Cs2Au2SnS4 (3) have been synthesized through direct reaction of the elements with a molten polyalkalithiogermanate(stannate) flux; at 650, 550, and 400 degrees C, respectively. Their crystal structures have been determined by single crystal X-ray diffraction techniques. 1 crystallizes in the monoclinic space group P2(1)/n with a=10.633(2) Angstrom, b=11.127(2) Angstrom, c=11.303(2) Angstrom: beta=115,37(3)degrees, V= 1208,2(3) Angstrom(3) and Z = 4, final R(Rw) = 0.045(0.106). 2 crystallizes in the tetragonal space group P4/mcc with a= 8.251(1) Angstrom, c=19.961(4) Angstrom, V=1358:9(4)Angstrom(3) and Z=4, final R(Rw) = 0.040(0.076)1 3 crystallizes in the orthorhombic space group Fddd with a=6.143(1)Angstrom, b=14.296(3)Angstrom, c = 24.578(5) Angstrom, V = 2158.4(7) Angstrom(3) and Z = 4, final R(R IV) = 0.039(0.095). The structures of 1, 2, and 3 consist of infinite, one-dimensional anionic chains containing X(2)Q(6)(4-) units linked by Au+ ions and charge balancing K+/Cs+ ions situated between the chains. All compounds were investigated with differential thermal analysis, FT-IR, and solid stale UV/VIS diffuse reflectance spectroscopy.