Liliane G. Hubert-Pfalzgraf, Valérie Abada and Jacqueline Vaissermann
The reaction between the cerium isopropoxide [Ce2(OPri)8(PriOH)2] and hexafluoroisopropyl alcohol (Hhfip) in THF at room temperature resulted in the formation of [Ce(hfip)4(THF)2(PriOH)x]. More stable compounds namely [Ce(hfip)4(diglyme)], [Ce(hfip)4(bipy)2] and [Ce(hfip)4(tmen)] were obtained if the alcoholysis was achieved in the presence of a Lewis base (diglyme = 2,5,8-trioxanonane, bipy = 2,2′-bipyridine, tmen = N,N,N
′,N
′-tetramethylethane-1,2-diamine). The use of N,N,N
′,N
″,N
″-pentamethyldiethylenetriamine (pmdien) afforded [Hpmdien]2[Ce(hfip)6] and [Ce(hfip)3(OPri)(pmdien)]. All compounds were volatile and characterized by elemental analyses, FT-IR, 1H and 19F NMR. The pmdien salt was also characterized by X-ray diffraction. The cerium atom is six-co-ordinated [Ce–O 2.183(5)–2.208(5) Å] with the CF3 groups forming nearly a crown (Ce
· · ·
F 4.06–4.32 Å). The metallic anion [Ce(hfip)6]2– and the [Hpmdien]+ cations are associated by a short F
· · ·
C contact (3.15 Å). The interactions are retained in solution as evidenced by 1H and 19F NMR.