With neutral complex 4 in hand, we evaluated its capabilities for fluoride uptake, on the basis of its likely higher Lewis acidity compared to anionic precursor 2. In our previous work, we obtained [Ln(X)2CaF] -systems using a method initially described by Roesky et al., in which a calcium amido complex (either isolated or generated in situ) undergoes metathesis with Me3SnF to generate a Ca-F bond. In the case of 4, no reaction is observed with K[HMDS], although the combination of K[HMDS]/2.2.2-cryptand in benzene leads to the formation of a single new species. However, NMR spectroscopy shows the new complex to possess C3-symmetry on the NMR timescale and single crystal X-ray diffraction revealed it simply to be [K(2.2.2crypt)][(t-BuTACN)Ca] (5) formed by nucleophilic demethylation.