Solid State Polyselenides and Polytellurides: A Large Variety of Se–Se and Te–Te Interactions

Abstract

A large variety of different interactions between the chalcogen atoms, Q, occur in the solid state structures of polyselenides and polytellurides, including both molecular and infinite units. The simplest motifs are classical Q22– dumbbells and nonlinear Qn2– chains (n = 3, 4, 5, ..), e.g. found in alkali metal polychalcogenides. In addition, nonclassical so-called hypervalent motifs exist in the form of linear Q34– units or within larger units such as Q44– and Q54–. Infinitely extended Q units include zigzag, cis/trans and linear chains, as well as planar and slightly puckered layers. Several of those are susceptible to Peierls distortions, leading to the formation of both commensurate and incommensurate superstructures and anomalies in transport properties, including metal-nonmetal transitions.

The Origin of Isotope Effects in Sonoluminescence Spectra of Heavy and Light Water

“…The Se 4 2– anion has a zigzag chain conformation and sits on an inversion center. The two terminal Se–Se bonds [2.330(1) Å] are significantly shorter than the middle Se–Se bond [2.399(1) Å], and the Se–Se–Se angles are 98.28(2)° (Figure 3), similar to the values found in other polyselenides 4. The Se 4 2– anion is flat with a torsion angle 0.00(3)° and almost parallel to the (001) plane.…”

Crystal structures of the four new quaternary copper(I)-selenides A0.5CuZrSe3 and ACuYSe3(A=Sr, Ba)

“…[5][6][7][8][9][10][11] Combining strong cations such as Ba with a CuQ network (Q = Se, Te) led towards a variety of new compounds with intriguing crystal structures containing Cu clusters and polychalcogen units such as hypervalent chains and square nets. [12][13][14][15] The open, layered crystal structure of the ACuMQ 3 (Q = S, Se, Te; M = Zr, Hf, U and lanthanides) family with its first member KCuZrQ 3 [16] has a remarkable flexibility towards element substitution resulting in the same or a similar structure types with the group subgroup relationship Cmcm-Pnma. [17] Up to now members of this family were obtained by combining di-(A 2+ ) and trivalent (M 3+ ) or mono-(A + ) and tetravalent (M 4+ ) cations with a [CuSe 3 ] 5 network.…”

Ein Iridium‐stabilisiertes, formal neutrales Te10‐Molekül mit Drei‐Zentren‐vier‐Elektronen‐Bindung

“…Mit Cs 3 Te 6 (Te 8 ) 2 [1] und Cs 4 Te 20 (Te 8 ) [2] wurde erstmals gezeigt, dass kronenfçrmige Te 8 -Ringe durch Einbettung in Kristallstrukturen stabilisiert werden kçnnen. Nachfolgend wurden homonukleare Spezies, wie Te 4 in [Te 4 {Cr(CO) 5 } 4 ] [3] oder Te 6 in Re 6 Te 10 Cl 6 (Te 6 ) [4] und (AgI) 2 (Te 6 ), [5] [6] Eine mannigfaltige Strukturchemie entwickelt Tellur in seinen polyanionischen [7] und polykationischen [8] Formen, in denen die Telluratome die Fähigkeit zur Ausbildung von 3-Zentren-4-Elektronen(3z-4e)-Bindungen demonstrieren. Solche "hypervalenten" Atome finden sich z.…”