{Ti6}/{Ti10} Wheel Cluster Substituted Silicotungstate Aggregates

Two novel Ti-oxo wheel cluster substituted silicotung-states (STs) [H2N(CH3)(2)](9)H-9[Ti6O6(SiW10O37)(3)]center dot 11H(2)O (1) and [H2N(CH3)(2)](16)H-10[Ti10O11(SiW10O37)(2)(SiW9O35)(2)]center dot 14H(2)O (2) have been made by hydrothermal reactions. The polyoxoanion of 1 is a ringshaped trimer where a Ti6O6 ({Ti-6}) wheel cluster is encapsulated by three divacant [SiW10O37](10-) (SiW10O37) fragments. However, 2 is built by two divacant SiW10O37 units and two rare trivacant [SiW9O35](12-)(SiW9O35) fragments and further installs an unprecedented Ti10O11 ({Ti-10}) double-wheel cluster. To the best of our knowledge, 2 is rare in POM chemistry. Studies on the catalytic oxidation properties reveal that 1 exhibits high catalytic activity toward the oxidation of various sulfides using H2O2 as an oxidant. Furthermore, 1 can be facilely recycled and reused for at least five cycles without obvious loss of catalytic activity.

Automated summary

Two novel Ti-oxo wheel cluster substituted silicotung-states exhibit high catalytic activity and good recyclability in catalyzing oxidation reactions.