Synthesis and structural characterization of novel tetranuclear organotitanoxane derivatives

Abstract

Synthesis of the novel titanoxane compounds, [(TiCl)(TiOH){(Ti)[μ-(η⁵-C₅Me₄SiMe₂O-κO)]₂(μ-O)}₂(μ-O)] (4) and [{Ti[μ-(η⁵-C₅Me₄SiMe₂O-κO)](μ-O)}₄] (5) by controlled reaction of the dinuclear titanium oxo complex [{Ti{μ-(η⁵-C₅Me₄SiMe₂O-κO)}Cl]₂(μ-O)] (1) with 2 equiv of LiOH is reported. Complex 4 is innovative and remarkable. It is one of the rare known examples of tetranuclear stable terminal hydroxo titanium complexes, with an open-chained structure, which coincides with the transient metal monohydroxo proposed in the stepwise pathway employed to justify the formation of the hexanuclear complex [{Ti[μ-(η⁵-C₅Me₄SiMe₂O-κO)](μ-O)}₆] (3) from 1. ¹H DOSY experiments were used to characterize complex 4. In addition, the structures of compound 5 and of precursor 1 were determined by single-crystal X-ray diffraction studies.