Transition metal alkoxides are important with respect to their chemistry and applications. For example, titanium tetraisopropoxide, Ti(OiPr)4, is used extensively as a catalyst in synthetic reactions, as well as a precursor for electronic ceramic thin-films and high temperature materials. Metal complexes containing chiral ligands are of even greater interest due to their mediation of asymmetric catalytic reactions and their potential use in the formation of functional chiral nanoporous materials. The synthesis and characterization of a series of chiral transition metal alkoxides will be reported. The reactions of Ti(NMe2)4 with excess (6 equiv) S-(+)-2-butanol or R-(-)-2-butanol yielded the S-(+) and R-(-) isomers of Ti[O-2-Bu]4, respectively. These chiral alkoxides were obtained cleanly in good yield after distillation and have been characterized by 1H and 13C NMR, and elemental analysis. The zirconium and hafnium analogues have also been prepared; differences in the synthetic procedures will be discussed. Characterization of the alkoxide complexes by polarimetry revealed a trend in optical activity. The specific rotation, [a]lT (in units of 10-1•deg•cm2•g-1), decreases in the order Ti[O-2-Bu]4: +90.045 (S), -85.561 (R); Zr[O-2-Bu]4: +23.157 (S), -18.840 (R); Hf[O-2-Bu]4: +17.153 (S). The results will be discussed in relation to the complex size, mass and density.
Back to Undergraduate Research (Posters)
Back to The 34th Northeast Regional Meeting (October 5-7 2006)