The conversion of multinuclear μ-oxo titanium(iv) species in the reaction of Ti(OiBu)4 with branched organic acids; results of structural and spectroscopic studies

Abstract

Crystalline materials have been synthesized in reactions of titanium(IV) tetraisobutoxide with branched organic acids (HOOCR′, R′ = CMe₂Et, ^tBu, CH₂^tBu) in the molar ratio 1 : 1 at room temperature under Ar atmosphere. Particular attention has been paid to the structural and spectral characterization of metastable intermediate complexes of general formula [Ti₇O₉(OⁱBu)₄(HOⁱBu)(OOCCMe₂Et)₆]₂ (1) and [Ti₆O₅(OⁱBu)₆(OOC^tBu)₈] (3), and their conversion towards more structurally stable compounds [Ti₆O₆(OⁱBu)₆(OOCC(Me)₂Et)₆] (2) and [Ti₆O₆(H₂O)₂(OⁱBu)₆(OOC^tBu)₆] (4). The hexanuclear structure of (5) ([Ti₆O₆(OⁱBu)₆(OOCCH₂^tBu)₆]) has been postulated on the basis of IR and ¹³C NMR spectroscopic data analysis. The possible reaction pathways which may occur during the formation of the above mentioned compounds are also discussed.