Preparation and Reaction of Lanthanide(II) Trifluoromethanesulfonates

Samarium(II) trifluoromethanesulfonate (triflate) and ytterbium(II) triflate are conveniently and cleanly prepared as a tetrahydrofuran solution from samarium(III) triflate and ytterbium(III) triflate, respectively, by treating them with ethylmagnesium bromide at room temperature.