The reaction of Na2Te4 with K2S5 in dimethylformamide in the presence of Ph4PCl gave (Ph4P)2[Te(S5)2] (1). Under the same conditions, the reaction of elemental tellurium with Na2Se5 afforded (Ph4P)2[Te(Se5)2] (II), while β-(Ph4P)2[Se(Se5)2] (III) was made by reacting Na2Se5 with I2. The X-ray powder diffraction studies showed that I, II and III are isostructural. The structures of I and III were determined by X-ray single crystal analysis. The [A(Q5)2]2- anions in the two compounds contain either a square-planar Te2+ in I or Se2+ centre in III, which is situated on an inversion centre and chelated by two S52- or Se52- ligands. The bond distances between the central A2+ and its surrounding four Q atoms are TeS(1) = 2.699(2) Å and TeS(5) = 2.752(2) Å, or SeSe(1) = 2.653(2) Å and SeSe(5) = 2.693(2) Å. SS bond distances [av. SS = 2.075(12) Å] or SeSe bond distances [av. SeSe = 2.314(13) Å] are normal and in good agreement with those found in other polysulphide or polyselenide compounds. The conformation of each AQ5 ring in I and III is very close to a "chair". The solution UV-vis spectra of DMF solutions for all three compounds are reported.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry
- Materials Chemistry