A mixed halothallate

Abstract

The stoichiometry of the reaction between Br₂(vapour) and TlCl(solid) has been established. The solid reaction product has been characterised to be Tl(I)[Tl(III)Cl₂Br₂] by chemical analysis, magnetic measurement, conductivity studies, i.r. and laser Raman spectroscopy. The crystal structure of Tl(I)[Tl(III)Cl₂Br₂] has been determined by X-ray diffraction method (powder pattern). The crystal lattice belongs to orthorhombic type with a_o = 8.513 Å, b_o = 6.983 Å, c_o = 5.880 Å, and cell volume = 349.5 ų. The unit cell contains 2 molecules of Tl(I)[Tl(III)Cl₂Br₂]. The pycnometric density, using cyclohexane as displacing liquid, has been found to be 5.544 g/cm³, whereas the X-ray density is 6.078 g/cm³. The kinetics and mechanism of reaction between Br₂ vapour and solid thallous chloride has also been investigated.