Alkylation of tellurium tetrachloride by trimethylaluminum. Synthesis and molecular structure of [Te(CH3)3][Al(CH3)2Cl2]: A novel organotelluronium-aluminum oligomer

Reaction of TeCl₄ with A1(CH₃)₃ in toluene affords the crystalline product [Te(CH₃)₃][Al(CH₃)₂Cl₂]. The title compound crystallized in the monoclinic space group P2₁/n with unit cell parametersa=11.630(3),b=12.595(4),c=8.409(2) Å,=89.97(2)°, andD_c=1.62 g cm^–3 forZ=4. Least-squares refinement based on 1354 observed reflectionsI3 (I) in the range 3.5<2<45.0° led to a finalR factor of 0.046 (R_w=0.067). The compound does not exist as discrete cations and anions but may be described as an organotelluronium-aluminum oligomer. The mean Te-C bond distance is 2.130(11) Å while the mean Al-Cl bond distance is 2.221(4) Å.