Efficient Catalytic Oxidative Desulfurization toward Thioether and Sulfur Mustard Stimulant by...

The design and synthesis of effective and recyclable oxidative desulfurization catalysts is of great importance in view of environmental protection and human health. Herein, a family of polyoxomolybdate-based inorganic-organic hybrid materials, namely, [Mn(TMR4A)(H₂O)₄][Mo₆O₁₉]·0.5CH₃CH₂OH·H₂O (1), [Ni(TMR4A)(H₂O)₄][Mo₆O₁₉]·0.5CH₃CH₂OH·H₂O (2), [Zn(TMR4A)(H₂O)₄][Mo₆O₁₉]·0.5CH₃CH₂OH·H₂O (3), and [Co₂(TMR4A)₂(H₂O)₄(β-Mo₈O₂₆)]·CH₃CN·12H₂O (4), were assembled by the functionalized resorcin[4]arene ligand (TMR4A) with polyoxomolybdate and metal ions under solvothermal conditions. In isostructural 1-3, the [M(TMR4A)(H₂O)₄]²⁺ species (M = Mn^II, Ni^II, Zn^II) and [Mo₆O₁₉]^2- anions are held together via C-H···O hydrogen bonds to give a 3D supramolecular architecture. In 4, two [Co(TMR4A)(H₂O)₂]²⁺ cations were linked by one [β-Mo₈O₂₆]^4- anion to produce an attractive molecular dimer. Remarkably, 1-4, as recyclable heterogeneous catalysts, exhibit efficient catalytic oxidation desulfurization activities toward thioethers. Particularly, 1, as a representative example, features selective catalytic oxidation for sulfur mustard simulant. Moreover, their electrochemical properties were also studied.