A₆U₃Sb₂P₈S₃₂ (A = Rb, Cs): Quinary Uranium(IV) Thiophosphates Containing the [Sb(PS₄)₃]^6– Anion

Abstract

The reaction of A2S3/U/P2S5/S at 500 °C affords the quinary U(IV) thiophosphates A6U3Sb2P8S32 (A = Rb, Cs). These compounds contain {U3(PS4)2[Sb(PS4)3]2}(6-) layers separated by alkali metal cations. The layers are composed of trimeric uranium units connected to each other by the thiophosphato-antimonite anion, [Sb(PS4)3](6-). This unit contains a central Sb(III) cation bound by three [PS4](3-) anions, creating a trigonal pyramidal environment around Sb(III). Each uranium cation is surrounded by eight sulfides in a distorted square antiprism that shares two edges with two other US8 units to form a trimeric [U3S18](24-) cluster. Magnetic susceptibility measurements indicate that the close proximity of the U(IV) within these clusters leads to antiferromagnetic ordering at 53 K. Reflectance spectroscopy indicates that these compounds are semiconductors with a band gap of 1.48 eV.

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 …”

The First Quinary Rare Earth Thiophosphates: Cs5Ln3X3(P2S6)2(PS4) (Ln = La, Ce, X = Br, Cl) and the Quasi‐Quaternary Cs10Y4Cl10(P2S6)3

“…While a total of ten quasi‐quaternary or quinary thiophosphates are known in the literature, none are containing rare earths or halides, and all exclusively contain [PS 4 ] 3– anions: CsLiU(PS 4 ) 2 , A 6 U 3 Sb 2 (PS 4 ) 8 ( A = Rb, Cs), Ag 2 NbTi 3 (PS 4 ) 6 S, KNb 1.75 V 0.25 (PS 4 )S 6 , KNb 1.77 Ta 0.23 (PS 4 )S 6 , K 0.34 Cu 0.5 Nb 2 (PS 4 )S 6 , K 0.5 Ag 0.5 Nb 2 (PS 4 )S 6 , Cs 0.5 Ag 0.5 Nb 2 P(PS 4 )S 6 , and Rb 0.38 Ag 0.5 Nb 2 (PS 4 )S 6 . Surprisingly, only one quasi‐quaternary selenophosphate Rb 4 Sn 2 Ag 4 (P 2 Se 6 ) 3 is reported to date.…”

Targeted Synthesis of Uranium(IV) Thiosilicates

“…The UV−vis spectrum of 1 has some features in common with the spectra of the previously reported uranium(IV) thiophosphate compounds. 18,42 An absorption band at ∼715 nm is associated with ligand-to-metal charge transfer, which was observed at wavenumbers of ∼730 nm in the thiophosphates. 1 absorbs light in the visible region; the absorption slightly decreases at longer wavelengths, which is consistent with the brown/almost black color of the crystals.…”

“…Numerous uranium chalcogenide compounds exhibiting complex structures, promising magnetic and electronic properties, and rare oxidation states − have been obtained from sulfide, halide, and other fluxes. − Driven by interest in the magnetic properties of uranium­(IV) compounds that offer a convenient probe for the magnetic behavior of 5f electrons, we have applied the iodide flux crystal growth approach to uranium­(IV) thiophosphates and obtained a new family of compounds with complex topologies . Extending this approach to new families of uranium compounds, we performed several syntheses involving silicon sulfide in an attempt to increase the content of positively charged countercations and extend the uranium thioanion framework by replacing PS 4 3– anions with SiS 4 4– .…”