Polychalcogenoaurates(I) with pseudo-onedimensional structures: Preparation and crystal structure of Cs2Au2Se3

Article abstract of DOI:10.1016/S0992-4361(98)80189-6

Cs₂Au₂Se₃ was obtained as red platelike crystals by reacting a stoichiometric mixture of Cs₂Se, Au and Se at 670K. It crystallizes in space group C2/c, Z = 4 with a = 9.769(5) A, b = 13.44(1) A, c = 7.178(3) A, β = 90.69(1)°. The crystal structure was determined from single crystal data and refined to a conventional R of 0.042 for 674 Fo's and 34 variables. The characteristic structural feature of this new selenoaurate is the formation of infinite helical anionic chains, _∞¹-[AuSeAuSe₂]^2- which run parallel to [001] and are separated by the alkali cations. The average Au-Se bond length is 2.402 A, the bond length in the Sea-unit is 2.436 A. Au...Au contacts of 3.200 A are formed within the anionic chains. The cesium atoms are coordinated to seven Se in an irregular configuration. Elsevier,.