Structure of the ambient temperature alkali metal molten salt AlCl3/LiSCN

The structure of the ambient temperature alkali metal molten salt system Li SCN/AlCl3 1:1 adduct was investigated by neutron diffraction, which demonst rates that the aluminum atom is surrounded by three chlorine atoms and one nitrogen atom, indicating the existence of the AlCl3NCS- anion, in which th e NCS- coordinates to the Al center through nitrogen. Molecular orbital cal culations using ab initio methods are also performed to study the optimized structures of the AlCl3NCS- and its isomer, AlCl3SCN-. The results are con sistent with the neutron diffraction data and indicate that AlCl3NCS- is th e major anionic complex in the 1:1 LiSCN/AlCl3 adduct. (C) 2001 American In stitute of Physics.