CRYSTAL-STRUCTURE DETERMINATION AND VIBRATIONAL-SPECTRA OF (T-BUNH(3))(2)[TEBR6] AND COMPARISONS WITH OTHER SOLIDS CONTAINING [TECL6](2-) OR [TEBR6](2-) IONS

The structure of(t-BuNH(3))(2)[TeBr6] determined by X-ray crystallography reveals the [TeBr6](2-) ion to be trigonally distorted with three long bonds of 2.761, 2.735 and 2,780 Angstrom and three short bonds of 2.609, 2.594 and 2.632 Angstrom. The longer set are involved in hydrogen bonds to the t-BuNH(3)(+) cation. The symmetry of [TeBr6](2-) is close to C-3v and this model fits the vibrational spectrum which contains Te-Br stretching frequencies of 148, 163, 180 and 201 cm(-1) active in both IR and Raman spectra. Solutions of TeCl4 in HCl yield, with t-BuNH(2), the double salt (t-BuNH(3))(2)[TeCl6]. 4t-BuNH(3)Cl in which the [TeCl6](2-) ion is shown by the vibrational spectrum to have a regular octahedral (O-h) structure exhibiting the frequencies v(1) 287, v(2) 247, v(3) 230, v(4) 158 and v(5) 131 cm(-1). The spectra of (dapH(2))[TeX(6)] (dap = 1,3-diaminopropane; X = Cl or Br) are reported and examined in relation to known structures.