Photo-redox reactivity of titanium-oxo clusters: mechanistic insight into a two-electron intramolecular process, and structural characterisation of mixed-valent Ti(iii)/Ti(iv) products.

ABSTRACT: Small titanium-oxo-alkoxide clusters, [TiO(OR)(O₂PR'₂)]₄, synthesised by the stoichiometric reaction of Ti(OⁱPr)₄, phosphinic acid and water, undergo a photo-redox transformation under long-wave UV light. The photo-reaction generates blue coloured, mixed-valence Ti(iii)/Ti(iv)-oxo clusters alongside acetone and isopropanol by-products. This reactivity indicates the ability for photoactivated charge separation to occur in even the smallest of Ti-oxo clusters. EPR and NMR spectroscopic studies support a photo-redox mechanism that occurs via an intramolecular, two-electron pathway, directly relating to current doubling effects observed at TiO₂ photoanodes in the presence of alcohols. The rate of photo-reaction is solvent

SUBMITTER: Kramer T 

PROVIDER: S-EPMC6640198 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature