Chemistry of Gold in Molten Alkali Metal Polychalcophosphate Fluxes. Synthesis and Characterization of the Low-Dimensional Compounds A₃AuP₂Se₈ (A = K, Rb, Cs), A₂Au₂P₂Se₆ (A = K, Rb), A₂AuPS₄ (A = K, Rb, Cs), and AAuP₂S₇ (A = K, Rb)

Abstract

The reaction of Au with a molten mixture of A 2 Q/P 2 Q 5 /Q (Q ) S, Se) produced the quaternary compounds A 3 AuP 2 Se 8 (A ) K, Rb, Cs) (I-III), A 2 Au 2 P 2 Se 6 (A ) K, Rb) (IV, V), A 2 AuPS 4 (A ) K, Rb, Cs) (VI-VIII), and AAuP 2 S 7 (A ) K, Rb) (IX, X). I-III crystallize in the acentric space group Cc (No. 9): I, a ) 7.122( 2) Å, b ) 12.527(3) Å, c ) 18.666(4) Å, β ) 96.06(2)°, Z ) 4. IV and V crystallize in the space group C2/m (No. 12): IV, a ) 12.289(2) Å, b ) 7.210(1) Å, c ) 8.107(1) Å, β ) 115.13(1)°, Z ) 2. VI and VII crystallize in the space group P2 1 /m (No. 11): VI, a ) 6.518(2) Å, b ) 6.747(2) Å, c ) 9.468(3) Å, β ) 92.98(2)°, Z ) 2. VIII crystallizes in the space group Pbcm (No. 57) with a ) 6.904(3) Å, b ) 20.093(6) Å, c ) 7.025(5) Å, and Z ) 4. IX and X crystallize in the space group C2/c (No. 15): IX, a ) 7.917(3) Å, b ) 9.247(2) Å, c ) 14.968(3) Å, β ) 91.84(9)°, Z ) 4. Compounds I-III have a one-dimensional structure with [AuP 2 Se 8 ] n 3nchains separated by A + cations. The monovalent Au cation is linearly coordinated to the new ligand [P 2 Se 8 ] 4-.IV and V possess a one-dimensional structure with [Au 2 P 2 Se 6 ] n 2nchains separated by A + ions. The monovalent Au cation is linearly coordinated to ethane like [P 2 Se 6 ] 4ligands. VI and VII have a one-dimensional structure with [AuPS 4 ] n 2nchains separated by A + cations. The Au + cation is linearly coordinated to alternating [PS 4 ] 3tetrahedra. The structure of VIII is related to that of I-III with [AuPS 4 ] n 2nchains. The diselenide of the [P 2 Se 8 ] 4unit is replaced by a second, essentially linear, S-Au-S linkage leaving the structure of the chain unchanged. IX and X have the [AuP 2 S 7 ] nchains with square planar Au 3+ centers. The compounds were characterized with differential thermal analysis, far-IR, Raman spectroscopy, solid-state UV/vis diffuse reflectance spectroscopy, and single-crystal optical spectroscopy. Cs 2 AuPS 4 , at T > 375 °C, converts to β-Cs 2 AuPS 4 , which is isostructural to K 2 AuPS 4 .

Synthesis and Characterization of the Rubidium Thiophosphate Rb6(PS5)(P2S10) and the Rubidium Silver Thiophosphates Rb2AgPS4, RbAg5(PS4)2 and Rb3Ag9(PS4)4

“…In contrast, the chemistry of silver in molten alkali metal polythiophosphate fluxes has not been investigated extensively compared to the other group 10 elements. Several alkali metal copper and gold thiophosphates have been reported: A 2 CuP 3 S 9 ( A = K, Rb), Cs 2 Cu 2 P 2 S 6 , K 3 CuP 2 S 7 , and A 2 AuPS 4 ( A = K, Rb, Cs), KAu 5 (PS 4 ) 2 , and A AuP 2 S 7 ( A = K, Rb) 1g,7,18. However, KAg 2 PS 4 is the only reported alkali metal silver thiophosphate up to date 1a.…”

K2AuPS4, Tl2AuPS4, K2AuAsS4, and KAu5P2S8: Syntheses, Structures, and Properties of Quaternary Gold Thiophosphate and Thioarsenate Compounds

“…During the preparation of this manuscript, one of the compounds presented here, K 2 AuPS 4 , was reported in the Compounds 1, 2, and 3 are isostructural. Their structures consist of anionic columns separated by potassium cations, literature [18] . The compounds were prepared from Au, A 2 S, S, and P 2 S 5 or As 2 S 3 .…”

First Examples of Gold Thiocadmates: A2Au2Cd2S4 (A=Rb, Cs) and K2Au4CdS4: Bright Photoluminescence from New Alkali Metal/Gold Thiocadmates

“…An example of this type of gold coordination and linking can be found in K 2 Au 2 SnS 4 and K 2 Au 2 Sn 2 S 6 , [3] A 3 AuP 2 Se 8 (A K, Rb, Cs), A 2 Au 2 P 2 Se 6 (A K, Rb), A 2 AuPS 4 (A K, Rb, Cs), and AAuP 2 S 7 (A K, Rb). [4] The coordination of flux-stabilized thioanions to metals is a rational and systematic route to quaternary chalcogenides. [5] This approach applied to the A/Cd/Au/Q system produced the first solid-state chalcogenides to contain both gold and cadmium.…”