Two sandwich‐type uranyl‐containing polytungstates catalyze aerobic synthesis of benzimidazoles
Yufeng Liu, Qi-Long Hu, Xue‐Jiao Chen, Ke Li, Pei Luo, Guo‐Ping Yang
Abstract
Diversified synthetic strategies are extremely important for the structural diversity of uranium‐containing polyoxometalates (U‐POMs) and their functional expansion. Herein, two sandwich‐type U‐POMs were reported, which are Na 5.6 K 6.4 [(UO 2 )(H 2 O)(TeW 9 O 33 )] 2 ·21H 2 O (UTeW 9 ) and Na 8.9 K 2.7 H 1.19 [K 0.79 (UO 2 ) 2.21 (PW 9 O 34 ) 2 ]·12H 2 O (UPW 9 ) using in‐situ strategy and lacunary precursor strategy, respectively. UTeW 9 shows a typical Keggin‐type open or half‐sandwich configuration. UPW 9 shows a typical Keggin‐type sandwiched structure containing significant disorders of K(I) and uranyl ions with a triangular configuration. In addition, UTeW 9 exhibits high efficiency in the catalyzed condensation of various o ‐arylenediamines and aldehydes for the aerobic synthesis of benzimidazoles with excellent yield.