PREPARATION AND CRYSTAL-STRUCTURE OF SNTL 4SE3 WITH A NOTE ON TLSE

We describe the preparation and crystal structure of SnTl4Se3. It crys tallizes as a low symmetric distorted derivative with the In5Bi3 type of structure, which itself should be considered as a subfamily of the Cr5B3 type of structure: a = 852.2(2) pm, c = 1 272.2(6) pm, c/a = 1.4 9, Z = 4. Short Sn-Se distances of 311 pm, and 326 pm, respectively, a re obtained in 1infinity[SnSe2/2] chains running along [001]. Furtherm ore, short TI-Se distances are found in quasimolecular bent moieties T 12Se: 300 pm, 313 pm, and 347 pm, respectively. SnTl4Se, is a semicond uctor. The conductivity of some closely related phases are also report ed. Finally, the structure of the well known compound TlSe has been re fined for the first time, in order to get some more information about Tl1+-Se distances for square-antiprismatic coordinated Tl1+ ions.