Synthesis of cationic cerium compounds [Cp*2Ce(L)2][BPh4] (L = tetrahydrofuran or tetrahydrothiophene) and the crystal structure of the tetrahydrothiophene derivative

Protolysis of the cerium alkyl Cp*2CeCH(SiMe3)2 (1) by triethylammoniumtetraphenylborate provides a useful route to cationic cerium compounds [Cp*2Ce(L)2][BPh4] (2, L = tetrahydrofuran; 3, L = tetrahydrothiophene). The crystal structure of the tetrahydrothiophene derivative was determined by X-ray diffraction, which showed it to consist of discrete [Cp*2Ce(THT)2]+ and BPh4- ions. The Cp* ring-centroids (Cent) and the sulphur atoms in the cation form a distorted tetrahedron with a Cent-Ce-Cent angle of 134.57(6)° and Ce-S distances of 3.058(1) and 3.072(1) Å.