Synthesis and characterisation of four new heterometal alkoxides: potential precursors for the MOCVD of ferroelectric oxides

Abstract

The new strontium–niobium heterometal complexes [SrNb2(OEt)8(μ2-OEt)2(μ2-O- dmae)2] 1, [SrNb2(OEt)8(μ2-OEt)2(μ2-O-dmae)2(EtOH)2] 2, and [SrNb2(OEt)6(μ2-OEt)4(μ2-O-bis-dmap)2] 3, and have been prepared from the reaction between [SrNb2(OEt)12] and the donor-functionalised alcohols dmaeH (dmaeH = N,N-dimethylaminoethanol) and bis-dmap [bis-dmapH = 1,3-bis(dimethylamino)propan-2-ol]. The new strontium–tantalum complex [SrTa2(OPri)8(μ2-OPri)2(μ2-O-dmae)2] 4, has been prepared from [SrTa2(OPri)8(μ2-OPri)4(PriOH)2] and dmaeH in an analogous manner. The complexes 2, 3, and 4 have been structurally characterised by single crystal X-ray diffraction, and are shown to be discrete alkoxide-bridged trinuclear molecules. The complexes are potential ‘single-source’ Sr–Nb and Sr–Ta precursors for the MOCVD of SrBi2Ta2O9 and SrBi2(TaxNb1−x)2O9, illustrated by the successful use of 1 for the MOCVD of strontium niobate, SrNb2O6.