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Abstract:
Polychalcogenides REX2-δ (X=S, Se, Te; 0≤δ≤0.2) of trivalent rare earth metals RE have been investigated in recent years to shed light on the structural diversity as a function of compositional, metric, thermodynamic, and electronic situation. Whereas the former aspects have comparable influence on the structures of all polychalcogenides REX2-δ, the bonding situation was assumed different for tellurides due to tellurium's higher tendency to delocalize electrons. The crystal structures generally contain puckered [REX] double slabs and planar [X] layers, the latter hosting different distortions from a square-like arrangement. The distortion patterns of sulfides and selenides can be understood by a Zintl-type approach; they are dominated by localization of valence electrons in mono- (X2−) or dinuclear (X22−) anions only. This review discusses crystal structures of some rare-earth metal polytellurides RETe2-δ (0≤δ≤0.2) and bonding features in the chalcogenide layers and relates them to their sulfide and selenide counterparts. © 2023 The Authors. Zeitschrift für anorganische und allgemeine Chemie published by Wiley-VCH GmbH.
