Ce(III)-Containing tungstotellurate(VI) with a sandwich structure: an efficient Lewis acid-base catalyst for the condensation cyclization of 1,3-diketones with hydrazines/hydrazides or diamines

A new Ce3+ modified Dawson-like polyoxometalate cluster (C2H8N)(12)Na-2[H-10{Ce(H2O)(5)}(2)(Te2W37O132)]39H(2)O was synthesized using pH and temperature-controlled one-pot strategy. The compound was characterized by single-crystal X-ray structure analysis, IR spectroscopy, thermogravimetric (TG) analysis, X-ray photoelectron spectroscopy (XPS), and electrospray ionization mass spectrometry (ESI-MS). Single-crystal X-ray structure analysis revealed that there was a new {Te2W37O132} structure and two Ce3+ in this compound. Moreover, it is notable that this compound presents excellent Lewis acid- and Lewis base activities in the condensation cyclization of 1,3-diketones with hydrazines/hydrazides or diamines. All the desired products were obtained in moderate to good yields (up to 99%) and with a high turnover number (up to 4347).