Notes. Thallium thioether chemistry. Synthesis and crystal structure of [Tl([9]aneS3)]PF6([9]aneS3= 1,4,7-trithiacyclononane), showing infinite helices of [Tl([9]aneS3)]+ fragments

Abstract

Treatment of TINO₃ with an excess of 1,4,7-trithiacyclononane ([9]aneS₃) in MeCN followed by addition of NH₄PF₆ affords the 1 : 1 complex [Tl([9]aneS₃)]PF₆, which crystallises in the orthorhombic space group P2₁2₁2₁ with a= 7.7655(11), b= 8.3767(18), c= 20.838(4)Å and Z= 4 as determined by X-ray crystallography. The structure shows the trithia ligand bound facially to the Tl^I centre, Tl–S(1) 3.114(3), Tl–S(4) 3.092(3) and Tl–S(7) 3.110(3)Å. A secondary interaction between the thallium and S(7′){in a neighbouring [Tl([9]aneS₃)]⁺ unit at (½+x, ½–y, ½–z)}, Tl–S(7′) 3.431(3)Å, gives overall [3 + 1] thioether co-ordination at Tl^I. These contacts between cations related by the 2₁ screw axis parallel to a link [Tl([9]aneS₃)]⁺ fragments to form infinite helices running in that direction. Further secondary interactions occur between the Tl^I centre and the fluorines of three different PF₆^– counter ions, Tl ⋯ F(2) 3.228(8), Tl ⋯ F(4) 3.389(8), Tl ⋯ F(3) 3.246(8) and Tl ⋯ F(5) 3.272(9)Å, to give formally an eight-co-ordinate metal complex.