Andrej Pevec, Alojz Demsar, Volker Gramlich, Sasa Petricek and Herbert W. Roesky
The reaction between [(C5Me5)TiF3] or [(C5Me4Et)TiF3] respectively in the presence of CaF2 (prepared in situ) resulted in the formation of [{(C5Me5)TiF3}4 CaF2] 1 or [{(C5Me4Et)TiF3}4 CaF2] 2, an X-ray study of compound 2 showed it to possess a core analogous to a crown ether.