Discovery of a new family member of arsenic–vanadium polyoxometalates with high catalytic performance for one-pot coupling of CO₂, epoxides and amines

Arsenic–vanadium polyoxometalates (POMs) represent a family of tremendous potential catalysts owing to their peculiar physical and chemical properties. Especially in CO₂ conversion, using POMs to catalyze the conversion of CO₂ and epoxide into chemical intermediates is the research hotspot. Here, A new family number of arsenic–vanadium POMs, [N(CH₃)₄]₄[As₈V₁₂O₃₈(H₂O)]·2H₂O ({As₈V₁₂O₃₈}), was reported and characterized by single-crystal X-ray diffraction, fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, etc. Different from other allotropicity, {As₈V₁₂O₃₈} shows a different structure pattern with an I-43d symmetry. The obtained {As₈V₁₂O₃₈} was employed as a catalyst for the CO₂ cycloaddition. The initial catalytic reaction confirmed that {As₈V₁₂O₃₈} can catalyze the formation of epoxy carbonate by using 1.01 kPa CO₂ and epoxide at 70 °C. Furtherly, when added amine in the catalytic system, oxazolidinone could be obtained by high yields, which provides an efficient way to convert CO₂ into profitable chemicals. Last, a possible catalytic reaction mechanism was proposed by using different characterization analyses. {As₈V₁₂O₃₈} first catalyzes the epoxide and CO₂ to form an epoxy carbonate and then catalyzes epoxy carbonate and benzylamine into oxazolidinone.