Alkoxysilanes. IV. Preparation of Alkoxysiloxy Derivatives of Titanium

Abstract

Alkoxysiloxy derivatives of titanium and polymeric substances with Ti–O–Si bonds were prepared. The reaction of titanium tetra-isopropoxide or bis (acetylacetonato)di-isopropoxytitanium with tri-t-butoxysilanol led to the formation of the derivatives of [(ButO)3SiO]nTi(OPri)4−n (n=2 and 3) and those of [(ButO)3SiO]2Ti(AcAc)2 respectively. In both of these series, the absorption peak of the Ti–O–Si bond in the IR spectrum shifted toward a lower wave number from the compounds of n=2 to those of n=3. The reaction of titanium tetra-isopropoxide with di-t-butoxysilanediol, as expected, gave a polymeric substance. In the reaction with bis(tri-t-butoxysiloxy)-silanediol, however, an unexpected cyclic compound consisting of the Ti–O–Si bond was obtained; its presence was confirmed by a study of the IR and NMR spectra, by elemental analysis, and by molecular-weight determination. In order to obtain a linear polymer, the reaction of the titanium acetylacetonato chelate with the silanediols was carried out to give a reddish-brown, highly viscous liquid or solid. These polymeric substances were soluble in common organic solvents and have an appreciable hydrolytic stability, but only a moderate thermal stability.