CS6RE6SE15, SYNTHESIS, ATOMIC ARRANGEMENT , AND THE CLASSIFICATION INA SYSTEM OF STRUCTURAL DESIGN OF TERNARY RHENIUM-CHALCOGENIDES 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 d egrees C. The X-ray single crystal structure determination revealed an atomic arrangement in which, isotypic to the already described compou nd Cs6Re6S15, [Re6Se8] units are linked by diselenide bridges to a thr ee-dimensional framework corresponding to the scheme {[Re6Se8](Se-2)(6 /2)}(4-). In this framework six Cs+ ions and one Se2--ion are inserted with respect to the complete formula Cs6Se{[Re6Se8](Se-2)(6/2)}. The classification of this atomic arrangement in a system of structural de sign of all so far known chalcogenides of rhenium and technetium A(x)M (6)X(z) with A (sic) alkaline- or alkaline earth metal and X (sic) sul phur or selenium is demonstrated in this paper.