Four New Terpyridine Complexes Based Polyoxometalates with [W₁₀O₃₂]^4- Anions as High-Efficiency Dual-Site Catalysis for Thioether Oxidation Reaction

Polyoxometalates modified with complex cations have attracted increasing attention because of the fascinating properties and the controllable structures. By adjusting the synthesis conditions, four new terpyridine complexes based hybrid POMs, [(TPY-H)CuCl](4) [W10O32]2DMF2H(2)O (1), [(TPY-H)Cu(DMSO)(H2O)](2)[W10O32]2H(2)O (2), [(TPY-H)(2)Cu](2)[W10O32]6DMSO8H(2)O (3) and [(TPY-Br)CuCl (DMSO)(H2O)](2)[(TPY-Br)CuCl](2)[W10O32]2DMSO4H(2)O (4), were prepared by using 'one-pot' method. Sing-crystal X-ray diffraction analyses, infrared radiation, etc., revealed the structural composition of compounds 1-4, which indicates that synthesis conditions have a directional regulatory effect on the compounds synthesis. Thioether oxidation catalytic reactions show 1-4 have good catalytic activities, and powder X-ray diffraction and thermogravimetry analysis show 1-4 have superduper catalytic stability. Moreover, 4 has better catalytic activity because of the different structure of terpyridine complexes. Therefore, a possible mechanism of dual-site catalysis by both cations and anions is proposed.