Letter | Published:

Structures of Polymeric Titanium Ethoxide and Titanium Oxide Ethoxides

Naturevolume 191pages273274 (1961) | Download Citation

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Abstract

RECENTLY, Martin and Winter1 suggested two new structures for trimeric titanium (IV) alkoxides. Their suggestion that Ti3(OR)12 may involve 6-co-ordinated titanium in a trigonal prismatic rather than an octahedral configuration is interesting but a decision on this must await the results of X-ray diffraction analysis. Besides providing a more symmetrical structure for the trimeric titanium chloride tributoxide they claimed that the trigonal prismatic structure also alleviates certain difficulties concerning the structures we proposed2 for the polymeric titanium oxide ethoxides, which were based on the octahedral trimer structural unit. There are two points at issue. First, they consider on mechanistic grounds that the formation of the trilinear polymer species Ti3(x + 1)O4x(OEt)4(x + 3) “requires statistically unfavourable mutual orientation of two Ti3(OR)8(OH)4 units before effective collision and expulsion of four water molecules could occur, etc.”. Secondly, they mention that our structure for Ti3(x + 1)O4x(OEt)4(x + 3) involves an unknown 4-covalent bonding arrangement between oxygen and its four nearest neighbours. Concerning the first point it must be emphasized that our structure was developed to account for the variation of the number average degree of polymerization as a function of the degree of hydrolysis for a whole series of titanium oxide ethoxides. The mechanism of the hydrolysis was not considered, it is indeed unknown, and it is of no significance provided that a rapid rearrangement of the initial hydrolysis products occurs, thus resulting in the formation of the most stable structure. Moreover, we reported evidence which suggested that disproportionation takes place and this involves rapid structural rearrangements between members of the polymer series :

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References

  1. 1

    Martin, R. L., and Winter, G., Nature, 188, 313 (1960).

  2. 2

    Bradley, D. C., Gaze, R., and Wardlaw, W., J. Chem. Soc., 3977 (1955).

  3. 3

    Barraclough, C. G., Lewis, J., and Nyholm, R. S., J. Chem. Soc., 3552 (1959).

  4. 4

    Zeitler, V. A., and Brown, C. A., J. Phys. Chem., 61, 1174 (1957).

  5. 5

    J. Chem. Soc., 4270 (1960).

  6. 6

    Bradley, D. C., Mehrotra, R. C., Swanwick, J. D., and Wardlaw, W., J. Chem. Soc., 2025 (1953).

  7. 7

    Barraclough, C. G., Bradley, D. C., Lewis, J., and Thomas, I. M., J. Chem. Soc. (in the press).

  8. 8

    Bains, M. S., Bradley, D. C., and Stothers, J. B. (unpublished results).

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Affiliations

  1. Department of Chemistry, University of Western Ontario, London, Ontario

    • D. C. BRADLEY
    •  & A. H. WESTLAKE

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https://doi.org/10.1038/191273a0

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