Synthesis in molten alkali metal polythiophosphate fluxes. The new quaternary bismuth and antimony thiophosphates ABiP(2)S(7) (A=K, Rb), A(3)M(PS4)(2) (A=K, Rb, Cs; M=Sb, Bi), Cs3Bi2(PS4)(3), and Na0.16Bi1.28P2S6

We used the molten alkali metal polychalcogenide flux method to prepare the new compounds ABiP,S, (A=K, Rb), A(3)M(PS4)(2) (A = K, Rb, Cs; M= Sb, Bi), Cs3Bi2(PS4)(3), and Na0.16Bi1.28P2S6. KBiP2S7 crystallizes in the monoclinic space group P2(1)/c with a = 9.500(3) Angstrom, b = 12.303(4) Angstrom, c = 9.097(3) Angstrom, beta = 90.59(3)degrees, V = 1063 Angstrom, at 23 degrees C. D-calc = 3.34 g cm(-3) mu = 184.85 cm(-1), 2 theta(max) = 50 degrees Mo K alpha. Data with I > 3 sigma(I) 1672, R/Rw(%) = 2.8/3.1. K3Bi(PS4)(2) crystallizes in the orthorhombic space group P2(1)2(1)2(1) with a = 23.894(8)(3) Angstrom, b = 6.799(3) Angstrom, c = 9.049(2) Angstrom, V = 1470 Angstrom(3), at -60 degrees C. D-calc = 2.91 g cm(-3), mu = 140.8 cm(-1), 2 theta(max) = 50 degrees. Data with I > 3 sigma(I) 1745, R/Rw(%) = 5.5/6.0. Cs3Bi2(PS4)(3) crystallizes in the monoclinic space group P2(1)/c with a = 18.091(5) Angstrom, b = 6.791(2) Angstrom, c = 18.723(3) Angstrom, beta = 97.95(2)degrees V = 2278 Angstrom(3), at 23 degrees C. D-calc = 3.77 g cm(-3), mu = 213.3 cm(-1), 2 theta(max) = 50 degrees. Data with I > 3 sigma(I) 2623, R/Rw(%) = 7.0/9.0. Na0.16B1.28P2S6 crystallizes in the monoclinic space group P2(1)/n with a = 6.554(2) Angstrom, b = 7.297(2) Angstrom, c = 9.371(1) Angstrom, beta = 92.04(2)degrees, V = 447.8 Angstrom(3), at 23 degrees C. D-calc = 3.73 g cm(-3), mu = 236.2 cm(-1), 2 theta(max) = 50 degrees. Data with I > 3 sigma(I) 892, R/Rw(%) = 7.7/8.5. The structural diversity in this family of compounds ranges from the one-dimensional non-centrosymmetric chains of A(3)M(PS4)(2) and the layered compounds, ABiP(2)S(7) and Cs3Bi2(PS4)(2), to the dense three-dimensional framework of Na0.16Bi1.28P2S6. KBiP2S7 is a layered solid with a complex new structure type, where corrugated layers are separated by eight-coordinate K+ ions. It contains a [P2S7](4-) ligand in a complicated coordination mode. The structure of K3Bi(PS4)(2) is assembled from one-dimensional, helical [Bi(PS4)(2)](3n-)(n) chains running along the crystallographic b-axis. The chain structure features two interesting binding modes for a tetrahedral [PS4](3-) ligand. The structure of Cs3Bi2(PS4)(3) has layers containing the same one-dimensional helical chains observed in K3Bi(PS4)(2). However, the PS4 unit acts as a bridge to a Bi-2(PS4)(2) dimeric unit. This unit is linked to another chain via a second bridging PS4 ligand to form sheets that are parallel to the [101] crystallographic plane. The structure of Na0.16Bi1.28P2S6 is three dimensional but consists of layers of P2S6 groups in the a-b plane separated by a single layer of Bi3+ ions. The ethane-like [P2S6](4-) ligand chelates to eight Bi atoms in a very convoluted fashion. Positional disorder was found between Na and Pi ions in one crystallographic site. Their synthesis, structural characterization, optical absorption and thermal properties are reported.