Synthesis and structural characterization of novel tetranuclear organotitanoxane derivatives

摘要

Synthesis of the novel titanoxane compounds, [(TiCl)(TiOH){(Ti)[μ- (η~5-C_5Me_4SiMe_2O-κO)] _2(μ-O)}_2(μ-O)] (4) and [{Ti[μ-(η~5- C_5Me_4SiMe_2O-κO)](μ-O)}_4] (5) by controlled reaction of the dinuclear titanium oxo complex [{Ti{μ-(η~5-C_5Me_4SiMe_2O- 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-(η~5-C_5Me_4SiMe_2O- 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.