According to XRF analysis, the dried product oxidized in
air contained 17.9% Ca, 35.1% Al, 3.4% Cl, 4.3% Na, and
0.2% Si. Calculation was based on an oxidic matrix. Hence,
the Al:Ca ratio was 1.96.
With THF. The same synthesis procedure was used as
described in section a, except for the solvent, which was
THF in this case. The product was a dry white, voluminous
powder. Soxhlet extraction with THF as solvent was applied
to separate the tetrahydroaluminate from the byproduct NaCl.
Due to the good solubility of the THF adduct obtained,
however, it is also possible to digest the raw product with
warm THF and separate the dissolved tetrahydroaluminate
by filtering. The solvent was removed using the drying
procedure described in section 3.1.2. After drying, the yield
was 70%, relating to Ca(AlH4)2.