Mass spectroscopic observations and chemical transport experiments with the systems VCl3/Al2Cl6 and VCl2/Al2Cl6

By mass spectrometry the equilibrium VClsub(3,s) + 0.5 Al2Clsub(6,g) = VAlClsub(6,g) has been determined: ΔH0(298) = 25.6(+- 0.5) kcal; ΔS0(298) = 23.0(+- 3) cal/K, ΔCp (assumed) = -4 cal/K. This is approximately in agreement with results determined by ligand field spectroscopy. For the dimerization of VClsub(3,g) values for ΔH and ΔS have been derived. For the VCl2/Al2Cl6 complex, observed by chemical transport, the formula VAl3Cl11 was given. The chemical transport of VCl2 wigh Al2Cl6 needs relatively high temperatures (973 → 873 K). In this case the addition of SiCl4 hinders the attack of the quartz ampoule by Al2Cl6. Using a VCl3 + VCl2 mixture, VCl3 is transported by Al2Cl6 (673 → 623 K) into the colder region. If afterwords the ampoule is reversed, VCl3 again moves into the colder region, but the thermal decomposition of VCl3 at the same time causes that a VCl2-residue remains in the hot region. (author)