Stepwise azido transfer to cerous tris(tert-butoxy)siloxide via trans-silylation with Me3SiN3

Abstract

Trimethylsilylhalogenides and -pseudohalogenides are frequently used reactants for (pseudo)halogen transfer, including derivatizations of cerium compounds. The present study describes the facile ligand exchange of cerium(III) complex [Ce{OSi(OtBu)₃}₃]₂ with Me₃SiN₃ generating the mixed azido/siloxy Ce^III complexes Ce₂[OSi(OtBu)₃]₅(N₃) and [Ce{OSi(OtBu)₃}₂(N₃)]₄. Although cerium siloxide complexes are a topical research field, thermal or photolytic ligand degradation as described in Ce^IV alkoxide chemistry has not been described. The activation of the azide complexes by irradiation with UV-visible light is easily achieved for such mixed azido/siloxy cerous complexes, as revealed by the identification of the homoleptic ceric complex Ce[OSi(OtBu)₃]₄.