Inorganic-organic hybrid polyoxovanadates based on [VO] or [VO] clusters: controllable synthesis, crystal structures and catalytic properties in selective oxidation of sulfides

By rationally controlling hydrothermal conditions, three new inorganic-organic hybrid polyoxovanadates (POVs) [Ni 2 (1-vIM) 7 H 2 O][V 4 O 12 ]·H 2 O ( 1 ), [Cu 2 (1-vIM) 8 ][V 4 O 12 ]·H 2 O ( 2 ) and [Co(1-vIM)H 2 O][VO 3 ] 2 ( 3 ) (1-vIM = 1-vinylimidazole) have been synthesized and thoroughly characterized by single X-ray diffraction (SXRD), powder X-ray diffraction (PXRD), infrared spectroscopy (FT-IR), and elemental analyses (EA). Interestingly, complexes 1 and 2 have similar structures including [V 4 O 12 ] 4− clusters; complex 3 , however, was isolated as a structure by including the [VO 3 ] 2 2− cluster under a different synthetic condition compared with those of 1 and 2 . Both complexes 1 and 2 display an interesting 3D supramolecular structure, and complex 3 shows a 2D two parallel networks supramolecular structure linked by a [Co 2 O 2 ] unit due to the different coordination environments of the central metals. Three inorganic-organic hybrid POVs as heterogeneous catalysts are active in the selective oxidation of sulfides to produce sulfoxides or sulfones with high conversion and high selectivity (up to 99.5% for sulfoxides and 98.5% for sulfones respectively catalyzed by 1 ). Complex 1 is also used as catalyst in the oxidative CEES (2-chloroethyl ethyl sulfide, a sulfur mustard simulant) abatement with high activity and selectivity toward the corresponding sulfoxide. Moreover, complex 1 can be reused at least three times in sulfoxidation reactions without losing its activity. Three inorganic-organic hybrid polyoxovanadates have been synthesized. Among them, complex [Ni 2 (1-vIM) 7 H 2 O][V 4 O 12 ]·H 2 O ( 1 ) exhibits extraordinary heterogeneous catalytic performance in the selective oxidation of sulfides using H 2 O 2 as the oxidant.