The reaction of Cu with a molten mixture of A2S/P2S5 (A = K, Rb, Cs) produced the quaternary compounds A2CuP3S9 (A = K, Rb) and Cs2Cu2P2S6. The reaction of Cu with a molten mixture of K2S/P2S5/S produced the quaternary compound K3CuP2S7. A2CuP3S9 (A = K, Rb); I, II, respectively) crystallizes in the space group P21/n (no. 14) for I: a = 6.8331-(6) Å, b = 23.562(2) Å, c = 9.5415(7) Å, β = 100.242(7)°, Z = 4, V = 1511.8(4) Å3, ρcalc = 2.298 g/cm3. Cs2Cu2P2S6 (III) crystallizes in the space group P21/c (no. 14) with a = 9.538-(3) Å, b = 12.793(4) Å, c = 10.429(4) Å, β = 103.76(2)°, Z = 4, V = 1236.1(7) Å3, ρcalc = 3.478 g/cm3. K3CuP2S7 (IV) crystallizes in the space group P21/a (no. 14) with a = 13.113(5) Å, b = 6.702(3) Å, c = 15.141(7) Å, β = 115.13(1)°, Z = 4, V = 1315(1) Å3, ρcalc = 2.35 g/cm3. The structure of I-II consists of novel one-dimensional [CuP3S9]n2n- chains separated by A+ cations. The chains run along the crystallographic b-axis. The Cu+ cation is in tetrahedral coordination with the cyclic [P3S9]3- anion, a new polythiophosphate unit. The structure of III has one-dimensional [Cu2P2S6]n2n- chains separated by Cs+ cations. The chains consists of alternating [Cu2]2+ dimers linked by the ethane-like [P2S6]4- units. The structure of IV is also one-dimensional, with [CuP2S7]n3n- chains separated by K+ ions. The Cu+ ions are in a slightly distorted trigonal planar environment with the [P2S7]4- units. Differential thermal analysis, far-IR, Raman spectroscopy, and optical spectroscopic data are reported. The results of a band structure calculation at the DFT-LMTO level for K2CuP3S9 are also discussed.
|Number of pages||10|
|Journal||Chemistry of Materials|
|Publication status||Published - Oct 1 1998|
ASJC Scopus subject areas
- Chemical Engineering(all)
- Materials Chemistry