Data for Photoactivation of titanium-oxo cluster [Ti 6 O 6 (OR) 6 (O 2 C t Bu) 6 ] : mechanism, photoactivated structures, and onward reactivity with O 2 to a peroxide complex

Mechanistic studies indicate that a two-electron (not free-radical) mechanism occurs in this process, which utilises the cluster structure to facilitate multielectron reactions. The photoreduced products [Ti6O6(OiPr)4(O2CtBu)6(sol)2], sol = iPrOH (2) or pyridine (3), can be isolated in good yield and are structurally characterized, each with two, uniquely arranged, antiferromagnetically coupled d-electrons. 2 and 3 undergo onward oxidation under air, with 3 cleanly transforming into peroxide complex, [Ti6O6(OiPr)4(O2CtBu)6(py)(O2)] (5). 5 reacts with isopropanol to regenerate the initial cluster (1) completing a closed cycle, and suggesting opportunities for the deployment of these easily made and tuneable clusters for sustainable photocatalytic processes using air and light.

The redox reactivity described here is only possible in a cluster with multiple Ti sites, which can perform multi-electron processes and can adjust its shape to accommodate changes in electron density.<br><br>Data to support article published in Chemical Science