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By a condensation reaction of 'Bu,Si(OH),(L) with titanium and germanium tetrahalides, several eight-membered titanium and germanium cyclosiloxane compounds were prepared in polar solvents. These were crystallized and identified by the usual physical techniques ('H, 13C and 29Si NMR spectroscopy, x-ray dimaction and mass spectrometry). Raman and IR spectra were also recorded, which confirmed the structure obtained by x-ray dimaction. The rings are well characterized by breathing modes which appear around 620-660 cm-' and Si-0-M stretching-bending modes which appear around 950-1000 cm-'. The vibrational modes characterizing the teributyl group are weakly coupled with those of the heterocycles. The corresponding observed bands are close to those observed for (L).

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