Cs6Re6Se15, synthesis, atomic arrangement, and the classification in a system of structural design of ternary rhenium- and technetium chalcogenides

The ternary selenide Cs6Re6Se15 was prepared via a reaction of caesium carbonate with rhenium in a selenium-charged hydrogen stream at 850 C. The X-ray single crystal structure determination revealed an atomic arrangement in which, isotypic to the already described compound Cs6Re6S15, [Re6Se8] units are linked by diselenide bridges to a three-dimensional framework corresponding to the scheme {[Re6Se8](Se2)6/2}±. In this framework six Cs+ ions and one Se2--ion are inserted with respect to the complete formula Cs6Se{[Re6Se8](Se2)6/2}. The classification of this atomic arrangement in a system of structural design of all so far known chalcogenides of rhenium and technetium AxM6Xz with A alkaline- or alkaline Earth metal and X = sulphur or selenium is demonstrated in this paper. (orig.)