Structure and physical properties of ternary uranium transition-metal antimonides U3MSb5 (M=Zr, Hf, Nb)

Syntheses, structures, and magnetic and optical properties of the compounds [Hg3Te2][UCl6] and [Hg4As2][UCl6]

“…DC magnetic measurements of [Hg 3 Te 2 ][UCl 6 ] were carried out with the use of a Quantum Design MPMS5 SQUID magnetometer. Twenty-seven milligrams of ground single crystals were loaded into a gelatin capsule.…”

“…Previous compounds have most commonly contained the [Hg 6 As 4 ] moiety, but other known structural fragments include [Hg 7 As 4 ], [HgAs 2 ], [Hg 3 As 2 ], [Hg 11 As 4 ], [Hg 23 As 12 ], and [Hg 13 As 8 ]. All examples of the [Hg 6 As 4 ] structural moiety contain As-As bonding in the form of As framework.…”

“…[Hg 6 As 4 ][AgCl 3 ] 2 [34] has a different arrangement in which the cavities are filled by an infinite chain of corner-sharing [AgCl 3 ] À tetrahedral anions. Both the [Hg 7 As 4 ] [11] and [Hg 3 As 2 ] [12] moieties also contain As 2 4À dumbbells, but in structures containing these species the cavities in the framework are of equal size. There is no As-As bonding in the [Hg 11 As 4 ] 4+ cation of [Hg 11 As 4 ][GaBr 4 ] 4 [14] so all As atoms may be assigned an oxidation state of À3.…”

“…The few with 5d transition metals that have been studied by single-crystal X-ray diffraction methods include Cs 8 Hf 5 UTe 30.6 [1], Ir 2 U 6 Se 15.5 [2], HfU 3 Sb 5 [3], and AuUSb 2 [4]. To probe 5d/5f systems, we have chosen the Hg/U system for which the binary phase diagram [5] reveals only the phases Hg 45 U 11 , Hg 3 U, Hg 2 U, and HgU.…”

“…These reagents have been shown to react with metals and chalcogens or pnictogens to produce quaternary compounds, most of which are nothing more than salts but most of which have been described as ''supramolecular compounds''. The chemistry of such compounds is rich and includes [Hg 3 Q 2 ][SiF 6 ] (Q ¼ S, Se, Te) [6], [Hg 3 Q 2 ][MX 6 ] (Q ¼ S, Se; M ¼ Zr, Hf; X ¼ Cl, Br) [7], [Hg 3 Se 2 ] [Se 2 O 5 ] [8], [Hg 6 T 4 ][MX 6 ]X (T ¼ P, As; M ¼ Mo, Ti; X ¼ Cl, Br) [9,10], [Hg 7 As 4 ][AgI 3 ] 2 [11], [Hg 3 T 2 ][TlX 3 ] (T ¼ As, Sb; X ¼ Cl, Br) [12], [Hg 6 As 4 ][YbBr 6 ]Br [13], [Hg 11 As 4 ][GaBr 4 ] 4 [14], and [Hg 2 As] 2 [CdI 4 ] [15]. Here we report the syntheses, crystal structures, optical properties, and magnetic properties of the first Hg/U chalcogenides or pnictides, namely [Hg 3 Te 2 ][UCl 6 ] and [Hg 4 As 2 ][UCl 6 ].…”