[Tc₆X₈] Clusters in ternary Technetium Chalcogenides

Abstract

Almost regular Tc6 octahedrons inside cubes constructed of chalcogen atoms X (X = S, Se) form the characteristic structural element in ternary alkali metal technetium chalcogenides. The Tc6X8 units are linked through X or X2 bridges (in the picture on the right the bridging X atoms are included with the central unit) to give three‐dimensional frameworks, and the alkali metal ions are inserted into suitable interstices.

Metal Halide Analogues of Chalcogenides: A Building Block Approach to the Rational Synthesis of Solid-State Materials

“…Only selected cluster phases are reported here to highlight the relationship between the halides and chalcogenides, since numerous reviews discuss such cluster phases. [99][100][101][102][103][104] Two basic cluster units are observed consisting of either an M 6 X 8 core in which the ligands cap the faces of the octahedral cluster, or with an M 6 X 12 core where the ligands bridge the edges of the cluster (Figure 7). [99][100][101][102][103][104] In both cases, these bridging ligands are designated as inner ligands, X i .…”

“…[99][100][101][102][103][104] Two basic cluster units are observed consisting of either an M 6 X 8 core in which the ligands cap the faces of the octahedral cluster, or with an M 6 X 12 core where the ligands bridge the edges of the cluster (Figure 7). [99][100][101][102][103][104] In both cases, these bridging ligands are designated as inner ligands, X i . Six terminal ligands attach to each type of cluster in apical positions and are designated as outer ligands, X a .…”

“…Nevertheless, slight compositional variations in the M/X ratio for both halides and chalcogenides and/or the inclusion of interstitial atoms or extracluster cations while maintaining a d-electron count of between d 2.5 and d 4 results in the formation of a large variety of octahedral cluster phases as summarized in Table . Only selected cluster phases are reported here to highlight the relationship between the halides and chalcogenides, since numerous reviews discuss such cluster phases. − …”

Synthesis, Structures, and Properties of New Chalcogenide‐Capped Octahedral Hexatechnetium(III) Complexes [Tc6S8X6]4– (X = Br, I), [Tc6Se8I2], and [Tc6Te15]

“…Se, x = 12-13), were firstly reported by Bronger et al [16,17] Kryutchkov et al reported a bromide-capped cluster [Tc 6 (µ 3 -Br) 5 Br 6 ] 2-in which the eight capping sites were not fully occupied. [18][19][20] In this study, we report on several new chalcogenide-capped hexatechnetium(III) complexes that are expected to be the precursors for the synthesis of various hexatechnetium(III) complexes.…”