Cover Picture

Abstract

The cover picture shows the arrangement of the 3-D [Hg 7 As 4 ] 4ϩ host framework and the AgI 3 2Ϫ guest anions in a novel supramolecular architecture [Hg 7 As 4 ](AgI 3 ) 2 , selfassembled from a heterogeneous system at high temperature. Although the hostϪguest interaction is weak, it governs both the geometry of the host framework (mercury atoms, blue; arsenic atoms, pink) and guest anions (silver atoms, red; iodine atoms, violet) and the positioning of the guest in the framework cavities. A mutual adjustment of the host and guests results is the unusual off-plane geometry of the AgI 3 2Ϫ anion. Details are discussed in the article of A. V. Shevelkov et al. on p. 1053 ff. MICROREVIEW Contents M. Vallet-Regí,* C. V. Ragel, 1029 A. J. Salinas Glasses with Medical Applications

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

“…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.…”

“…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. Rather, there are 2 1 ½Hg 6 As 4 layers with Hg 6 As 6 rings that are interconnected in the [001] direction alternately by Hg 2 2+ and Hg 3 2+ units.…”

“…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 ].…”

From Discrete to Extended Guests: A Novel Supramolecular [Hg6As4](AgCl3)2 Assembly Featuring One‐Dimensional (AgCl3)2− Anions

“…The guests that take their ''assigned'' positions within the cavities of the framework have been represented so far by discrete anions only. Octahedral, [5] tetrahedral, [6] pyramidal, [7] and triangular [2] anions have been successfully embedded into closed cavities of host frameworks of complementary topology. We therefore tried to find out if infinite anions could be accommodated by a mercuryϪpnicogen cationic matrix.…”