Novel oligomeric titanasiloxanes have been synthesized in good yields by reaction ofsterically demanding organosilanetriols with titanium alkoxides. The silanetriols
tBu
2(Me
3Si)FlSi(OH)
3 (
5), (Me
3Si)FlSi(OH)
3 (
6), and MeFlSi(OH)
3 (
7) and the titanium alkoxides Ti(OEt)
4, Ti(O
iPr)
4, and Ti(O
iPr)
2(acac)
2 have been used as starting materials (Fl = fluorenyl).Quite different structures are obtained by only small modifications of the organic substituentsof the substrates. Thus, the condensation reactions result in the formation of the polyhedraltitanasiloxanes [
tBu
2(Me
3Si)FlSi]
4O
12[TiOEt]
4 (
8), [(Me
3Si)FlSi]
2O
5[Ti(OEt)]
4[
2-OEt]
6[
4-O](
9), ([
tBu
2(Me
3Si)FlSi]
3O
10[Ti(O
iPr)]
4[
2-O
iPr]
2[
3-O]Ti)
2O (
10), and [MeFlSi]
2O
8[Ti(O
iPr)]
6[
2-O
iPr]
4[
3-O]
2[PhNH
2]
2 (
11) and the cyclic titanasiloxane [MeFlSi(O
iPr)]
2O
4[Ti(acac)
2]
2 (
12).A 1:1 stoichiometry of the starting materials leads to
8 and
12 in quantitative yield, while
9-
11 are isolated in minor quantities. If the appropriate substrate ratio is used, the lattercompounds can also be obtained in high yields. All titanasiloxanes have been characterizedby X-ray crystallography, NMR, IR, and elemental analysis.