Supramolecular Assembly Based on Octamolybdate and Triazole Derivative: Crystal Structure and Catalytic Application in Olefin Epoxidation

A novel polyoxometalate-based compound, [H(atrz)] 4 [(atrz) 2 (Mo 8 O 26 )]·2H 2 O ( 1 ) (atrz = 3-amino-1,2,4-triazole), has been synthesized by traditional hydrothermal method, and characterized by means of elemental analysis, FT-IR spectroscopy, Powder X-ray diffraction and single-crystal X-ray. The compound 1 contains a 2D supramolecualr layer which is constructed from [(atrz) 2 (γ-Mo 8 O 26 )] 4− units via intermolecular hydrogen-bonding interactions. Furthermore, the adjacent 2D layers are packed together through the aromatic π⋯π stacking interactions and exhibits a 3D supramolecular structure. The catalytic properties of 1 were investigated in olefin epoxidation with tert -butylhydroperoxide ( t -BuOOH) as the oxidant. It was found that compound 1 could serve as active and stable heterogeneous catalyst for the epoxidation of cyclooctene and 1-octence. Besides, introducing copper ions into compound 1 could further improve the catalytic activity for olefin epoxidation.