2 Homometallic Alkoxides

86 Alkoxo and Aryloxo Derivatives of Metals
23°C 37°C
50°C 60°C
Figure 2.5 Variable temperature 1 H NMR spectra
of Ta2⊲OPr i ⊳10 ⇀↽ Ta⊲OPr i ⊳5.
0.44 M 0.25 M
0.13 M 0.04 M
Figure 2.6 1 H NMR spectra of Ta2⊲OPr i ⊳10 ⇀↽
2Ta⊲OPr i ⊳5.
other two signals whereas decreasing the temperature had the reverse effect on the
spectrum. 562 On adding isopropyl alcohol to the pentaisopropoxide, the high field septet
was shifted to still higher field by coalescence with the isopropyl alcohol signal and
the intensities of the two low-field septets was diminished. On this basis the high-field