Comprehensive Uranium Thiophosphate Chemistry: Framework Compounds Based on Pseudotetrahedrally Coordinated Central Metal Atoms

Abstract

Abstract. The new ternary compounds UP 2 S 6 , UP 2 S 7 , U(P 2 S 6 ) 2 , and U 3 (PS 4 ) 4 were prepared from uranium metal, phosphorus pentasulfide, and sulfur at 700°C. The crystal structures were determined by singlecrystal X-ray diffraction methods. UP 2 S 6 (I) crystallizes in the ZrP 2 S 6 structure type [tetragonal, P4 2 /m, a = 6.8058(7) Å, c = 9.7597(14) Å, Z = 2], which consists of central uranium(IV) atoms coordinated by P 2 S 6 4-anions (staggered conformation). The anions are two-dimensional connectors for four uranium cations arranged in one plane. The structure of UP 2 S 7 (II) [orthorhombic, Fddd, a = 8.9966 (15) ligands, the resulting 3D network contains large pores (diameter approx. 3.5 ϫ 16.7 Å). In the previously reported compound U(P 2 S 6 ) 2 (III) [I4 1 /a, a = 12.8776(9) Å, c = 9.8367(10) Å, Z = 2], the

Synthesis and Crystal Structure of Cs2U2(P2Se9)(Se2)2

“…Reported examples include the ternaries ThP 2 S 6 , UP 2 S 6 , U(P 2 S 6 ) 2 , UP 2 S 7 ,, UP 2 S 9 , and U 3 (PS 4 ) 4 ; the quaternaries Cs 4 Th 4 P 4 Se 26 , Rb 4 U 2 P 5 Se 17 , Rb 4 U 4 P 4 Se 26 , A 2 ThP 3 Se 9 ( A = K, Rb), Cs 4 Th 2 P 5 Se 17 , A 11 U 7 (PS 4 ) 13 ( A = K, Rb), CsLiU(PS 4 ) 2 , Cs 8 U 5 (P 3 S 10 ) 2 (PS 4 ) 6 , A 5 An (PS 4 ) 3 ( A = K, Rb, Cs and An = U, Th), Cs 4 Th 2 P 6 S 18 ; AkAn (PS 4 ) 2 ( Ak = Sr, Ba and An = U, Th); and the quintary A 6 U 3 Sb 2 P 8 S 32 …”

Ag5U(PS4)3: A Transition-Metal Actinide Phosphochalcogenide

“…Small blocks of a size suitable for single-crystal structure determination showed a composition Ag/U/P/S ≈ 5:1:3:12. Some of the larger crystals were analyzed consistent with UP 2 S 6 …”

“…The greater diversity of stoichiometries among the phosphochalcogens arises from their ability to form Q−Q bonds that leads to polymeric substructures such as PQ3, P2Q6, P2Q10, P4Q13, P6Q12, and PQ6. [6][7][8][9][10] Known phosphosulfides include ternaries such as UP1-xSx, 11 UPS, 12 ThP2S6, 13 UP2S6, 14 U(P2S6)2, 14 UP2S7, 14,15 UP2S9, 15 and U3(PS4)4; 14 quaternaries such as A11U7(PS4)13 (A = K, Rb), 16 CsLiU(PS4)2, 17 Cs8U5(P3S10)2(PS4)6, 8 A5An(PS4)3 (A = K, Rb, Cs; An = U, Th), 8 AkAn(PS4)2 (Ak = Sr, Ba; An = Th, U), 18 and Cs4Th2P6S18; 19 Rb4U2(P2Se6)2.5(Se2), 25 Cs2An2(P2Se9)(Se2)2 (An = U, Th), 26,27 Rb7Th2(PSe4)3(P2Se6)1.5, 19…”

“…The greater diversity of stoichiometries among the phosphochalcogens arises from their ability to form Q−Q bonds that leads to polymeric substructures such as PQ 3 , P 2 Q 6 , P 2 Q 10 , P 4 Q 13 , P 6 Q 12 , and PQ 6 . 6−10 Known phosphosulfides include ternaries such as UP 1−x S x , 11 UPS, 12 ThP 2 S 6 , 13 UP 2 S 6 , 14 U(P 2 S 6 ) 2 , 14 UP 2 S 7 , 14,15 UP 2 S 9 , 15 and U 3 (PS 4 ) 4 ; 14 quaternaries such as A 11 U 7 (PS 4 ) 13 (A = K, Rb), 16 CsLiU(PS 4 ) 2 , 17 Cs 8 U 5 (P 3 S 10 ) 2 (PS 4 ) 6 , 8 A 5 An(PS 4 ) 3 (A = K, Rb, Cs; An = U, Th), 8 AkAn(PS 4 ) 2 (Ak = Sr, Ba; An = Th, U), 18 and Cs 4 Th 2 P 6 S 18 ; 19 and the quintaries or greater such as A 6 U 3 Sb 2 P 8 S 32 , 20 Cs 5 Na 6 [U(PS 4 ) 4 ](PS 4 ), 21 Rb 5 Na 3 [U-(PS 4 ) 4 ], 21 CsNa[U(PS 4 ) 2 ], 21 Cs 1.67 Na 0.52 I 0.19 [U(PS 4 ) 2 ], 21 Cs 1.033 Na 1.343 I 0.376 [U(PS 4 ) 2 ], 21 and Rb 1.35 Na 0.93 I 0.28 [U-(PS 4 ) 2 ]. 21 However, there are also examples of phosphoselenides and less so of phosphotellurides.…”

Facile Oxide to Chalcogenide Conversion for Actinides Using the Boron–Chalcogen Mixture Method

“…Actinide chalcogenides adopt diverse structure types with distinct chemical compositions and specific actinide oxidation states, − which offer unique opportunities for studying 5f electron properties. − The synthesis of these materials can be achieved by a limited set of synthetic routes that include the traditional solid-state approach, − chemical vapor transport, − and the molten flux technique. − Regardless of the method chosen, there are two general actinide precursors that are consistently usedthe actinide metals and binary actinide chalcogenides. ,− One of the main obstacles faced when synthesizing the actinide chalcogenides are actinide oxide and oxychalcogenide impurities that often contaminate the resulting products and interfere with their property measurements. − Due to the high oxygen affinity of the actinides, even trace amounts of oxygen in the system will inevitably result in formation of these impurities. Although careful oxygen exclusion from the reaction media is an intuitive and straightforward approach for avoiding oxide impurities, it is unfortunately often nearly impossible to completely eliminate oxide contamination present in the reagents themselves. , This difficulty of needing to effectively deal with oxide or oxychalcogenide impurities in the starting materials motivated us to explore different synthetic approaches that would allow for the use of oxygen-contaminated reagents, or even oxides themselves, as the starting materials for the synthesis of oxygen-free actinide chalcogenides.…”