Abstract
Hydrolysis and polymerization of dimethyldiethoxysilane (DMDE), methyltrimethoxysilane (MTMS) and tetramethoxysilane (TMOS) in the presence of aluminum acetylacetonate (Al(acac)3) have been investigated by infrared and NMR spectroscopy. In the absence of acidic catalyst, Al(acac)3 catalyzes the hydrolysis of all the silanes. The catalytic activity of Al(acac)3 is less than that of HNO3, but larger than that of NH3. The hydrolysis rate increases with increasing concentration of Al(acac)3 in DMDE. The hydrolysis of TMOS occurs rapidly after an inductive period, which becomes longer with addition of Al(acac)3. The results are explained by assuming an Al(acac)3 catalyzed hydrolysis and a silanol catalyzed hydrolysis. The addition of Al(acac)3 causes changes in polymerization of the resultant silanols. In DMDE and MTMS, it stabilizes the silanols at the early stage, and then enhances their polymerization. The polymerization in TMOS leads to the formation of precipitates that have a high degree of polymerization. The polymerization appears to proceed via a deprotonation mechanism including transfer of protons from silanols to Al(acac)3. The present results strongly suggest that, besides acids and bases, metal complexes can be used as catalysts for the formation of siloxanes under ambient conditions.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Sol-Gel Technology for Thin Films, Fibers, Preforms, Electronic,and Specialty Shapes, edited by L.C. Klein (Noyes, Park Ridge, NJ, 1988). C.J. Brinker and G.W. Scherer, Sol-Gel Science: The Physics and Chemistry of Sol-Gel Processing (Academic Press, New York, 1990). S. Sakka, in Treatise on Materials Science and Technology, edited by M. Tomozawa and R.H. Doremus (Academic Press, New York, 1982).
E.J.A. Pope and J.D. Mackenzie, J. Non-Cryst. Solids 87, 185(1986).
R.K. Iler, The Chemistry of Silica (Wiley, New York, 1979).
M. Yamane, S. Inoue, and A. Yasumori, J. Non-Cryst. Solids 63, 13 (1984). S. Sakka, H. Kozuka, and S. Kim, in Ultrastructure Processing of Advanced Ceramics, edited by J.D. Mackenzie and D.R. Ulrich (Wiley, New York, 1988), p. 159.
D.W. Schaefer and K.D. Keefer, in Better Ceramics Through Chemistry, editedby C.J. Brinker, D.E. Clark, and D.R. Ulrich (Elsevier, New York, 1984), p. 1.
S. Sakka, in Better Ceramics Through Chemistry, C.J. Brinker, D.E.Clark, and D.R. Ulrich (Elsevier, New York, 1984), p. 91.
J. Sol-GelSci. Technol. 7 (1996) (Special Issue: Biochemical Aspects).
B.C. Dave, J.M. Miller, B. Dunn, J.S. Valentine, and J.I. Zink, J. Sol-Gel Sci.Technol. 8, 629 (1997).
K.J. McNeil, J.A. DiCaprio, D.A. Walsh, and R.F. Pratt, J. Am. Chem. Soc. 102, 1859 (1980).
A.A. Humffrayand J.J. Ryan, J. Chem. Soc. B 1138 (1969).
E.R. Pohl and F.D. Osterholtz, in Molecular Characterization of Composite Interfaces, edited by H. Ishida and G. Kumar (Plenum, New York, 1985), p. 157.
Z. Zhang, Y. Tanigami, and R. Terai, J. Non-Cyst. Solids 191, 304(1995). Z. Zhang, Langmuir 13, 473 (1997).
U. Jäqlid and O. Lindqvist, Acta Chem. Scand. 44, 765 (1990). Acta Chem. Scand. 45, 887 (1991).
S.C. Deshmukh and E.S. Aydil, J. Vac. Sci. Technol. A 13,2355 (1995).
R.M. Silverstein, G.C. Bassler, and T.C. Morrill,Spectrometric Identification of Organic Compounds (Wiley, New York, 1981).
N. Wright and M.J. Hunter, J. Am. Chem. Soc. 69, 803 (1947). J.F.Brown, Jr., J. Am. Chem. Soc. 87, 4317 (1965). R. Konopka and B. Stojczyk, Acta Phys. Polon. A40, 537 (1971).
C.J. Brinker and D.M. Haaland, J. Am. Ceram. Soc.66, 758 (1983). A. Duran, J.M. Fernandez-Navarro, P. Casariego, and A. Joglar, J. Non-Cryst. Solids 85, 69 (1986).
L.W. Kelts, N.J. Effinger, and S.M. Melpolder,J. Non-Cryst. Solids 83, 353 (1986).
A.R. Siedle, inComprehensive Coordination Chemistry, edited by S.G. Wilkinson (Pergamon, Oxford, 1987), Vol. 2, chapt. 15.4.
M. Sedlar and M. Sayer, J. Sol-Gel Sci. Technol. 5, 27 (1995).
L.L. Funck and T.R. Ortolano, Inorg. Chem. 6, 567 (1967).W.R. May and M.M. Jones, J. Inorg. Nucl. Chem. 25, 507 (1963).
Nuclear Magnetic Shift Reagents, edited byR.E. Sievers (Academic Press, New York, 1973).
T.S. Davis and J.P. Fackler, Jr., Inorg. Chem. 5, 242 (1966). G.S. Vigee and C.L. Watkins, Inorg. Chem. 16, 709 (1977).
M.J. Van Bommel, T.N.M. Bernards, and A.H. Boonstra, J. Non-Cryst. Solids 128, 231 (1991).
C.J. Brinker,J. Non-Cryst. Solids 100, 30 (1988).
F.D. Osterholtz and E.R. Pohl,in Silane and Other Coupling Agents, edited by K.L. Mittal (VSP, The Netherlands, 1992).
J. Chojnowski, S. Rubinsztajn, and L. Wilczek,Macromolecules 20, 2345 (1987).
H. Imura, A. Oshiro, and R. Shiga, Solvent Extr. Ion Exch. 13, 1009 (1995). C. Corvaja and G. Ciacometti, J. Mol. Struct. 2, 239 (1968).
J.F. Brown, Jr., J. Am. Chem. Soc.87, 4217 (1965).
A.J. Barry, W.H. Daudt, J.J. Domicone, and J.W. Gilkey, J. Am. Chem. Soc. 77, 4248 (1955). L.H. Vogt, Jr. and J.F. Brown, Jr., Inorg. Chem. 2, 189 (1963).
Z. Zhang, Y. Tanigami, R. Terai, H. Wakabayashi, and S. Sakka, J. Phys. Chem. B 101, 1328 (1997).
R.K. Iler, The Chemistry of Silica (Wiley, New York, 1979), p. 174.
W. Stöber, A. Fink, and E. Bohn, J. Colloid Interface Sci. 26, 62 (1968).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Zhang, Z., Sakka, S. Hydrolysis and Polymerization of Dimethyldiethoxysilane, Methyltrimethoxysilane and Tetramethoxysilane in Presence of Aluminum Acetylacetonate. A Complex Catalyst for the Formation of Siloxanes. Journal of Sol-Gel Science and Technology 16, 209–220 (1999). https://doi.org/10.1023/A:1008761002205
Issue Date:
DOI: https://doi.org/10.1023/A:1008761002205