. Can. J. Chem. 70, 726 (1992). Addition of B(OTeF,), to TIOTeF, in the weakly coordinating solvents dichloromethane, 1,2-dichloroethane, and 1,1,2-trichlorotrifluoroethane produces solutions of M(solv).,+B(OTeF,),-. When the solvent was 1,2-dichloroethane, the crystalline compound TI( 1 ,2-C2H,Cl2)B(OTeF5), was isolated and studied by X-ray crystallography: triclinic, space group p i , a = 9.221 (4), b = 11.396 (S), c = 12.538 (4) A, cx = 110.75 (3)", P = 101.72 (3)", y = 99.74(3)",Z = 2, T = -116°C. The Tl(1 ,2-C2H,C12)+ cation contains a five-membered chelate ring with T I 4 1 distances of 3.138 (4) and 3.179