Der Ligandenaustausch im Kristallgitter von (PyH)2[Ta6Br12]Cl6

Ligand Replacement in the Crystal Lattice of (PyH)₂[Ta₆Br₁₂]Cl₆ Solid (PyH)₂[Ta₆Br₁₂ⁱ]Cl₆^a transforms exothermically at 210°C. In this way the Cl^a atoms outside of the complex are going instead of Brⁱ into the inside position; e.g. [Ta₆Br₁₂]Cl₆^2? → [Ta₆Br₆Cl₆]Br₆^2?. After each transformation Cl is brought in the outside position of the complex by recrystallization from a solution containing HCl. One gets in the following transformation step [Ta₆Br₃Cl₉]⁴⁺ and finally in the third step [Ta₆Br_1.5Cl_10.5]⁴⁺. Both formula are empirical formula. They consist of [Ta₆Br₆Cl₆]⁴⁺ and [Ta₆Br₂Cl₁₀]⁴⁺; and [Ta₆Br₆Cl₆]⁴⁺, [Ta₆Br₂Cl₁₀]⁴⁺ and [Ta₆Cl₁₂]⁴⁺, respectively. This result is in agreement with the theory.