Abstract
A study has been made of the photochemical reactions of titanium(IV) peroxo complexes formed in the reaction of titanium tetrachloride with hydrogen peroxide in alcoholic solutions and which are characterized by intense charge transfer bands at 360–425 nm. Irradiation of the solutions with light of λ = 254 nm leads to the decomposition of the titanium(IV) peroxo complexes, the formation of titanium(III) compounds, as well as the oxidation of the alcohol to aldehyde. In the irradiated frozen solutions associated complexes of titanium(III), organic free radicals formed from the alcohol molecule, as well as peroxy radicals have been identified by EPR. Irradiation with light corresponding to the longwave band of the peroxo complexes leads to their decomposition but titanium(III) compounds and alcohol oxidation products are not formed in this case. In irradiated frozen solutions the formation of paramagnetic titanium(IV) complexes containing the fragment Ti...O ∸2 has been established, as well as other paramagnetic particles identified tentatively as coordinated Ti...O ·2 radicals or radical pairs. It is shown that the decomposition of hydrogen peroxide in the presence of titanium(IV) compounds is photocatalytic.
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Translated from Teoreticheskaya i éksperimental'naya Khimiya, Vol. 24, No. 1, pp. 67–74, January–February, 1988.
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Kuchmii, S.Y., Korzhak, A.V. & Kryukov, A.I. Photochemical properties of peroxo complexes of titanium, intermediate products in the photocatalytic liquid-phase oxidation of alcohols. Theor Exp Chem 24, 62–68 (1988). https://doi.org/10.1007/BF01392192
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DOI: https://doi.org/10.1007/BF01392192