Methanolothermale Synthese und Kristallstruktur von Tetraselenidoarsenaten( V) und -antimonaten(V) des Rubidiums und Cäsiums / Methanolothermal Synthesis and Crystal Structure of Tetraselenidoarsenates(V) and -antimonates(V) of Rubidium and Cesium

Abstract

Abstract Tetraselenidoarsenates(V) and -antimonates(V), Rubidium, Cesium, Methanolothermal Synthesis, Crystal Structure Methanolothermal reaction of M2CO3 (M = Rb, Cs) with E2Se3 (E = As, Sb) and Se at temperatures in the range 180 -200°C leads to the formation of tetraselenidoarsenates(V) and -antimonates(V) M3ESe4 in moderate to quantitative yields. All four compounds crystallize in the (NH4)3AsS4 structure type (space group Pnma) and contain isolated slightly distorted tetrahedral ESe3- 4 anions with crystallographic CS symmetry. Both of the independent cations are coordinated in an irregular manner by seven Se atoms.