Efficient catalysis of Knoevenagel condensation by 1D copper-containing heteropolyoxoniobate at room temperature

Abstract

A 1D copper-containing organic-inorganic hybrid heterpolyoxoniobate, H3[K(H2O)6][K2(H2O)10]2[Cu(en)2(H2O)2][Cu(en)2(Nb6O19Cu(en))2]·24H2O (HPONb 1), has been synthesized to heterogeneously catalyze Knoevenagel condensation at room temperature with high yields and cyclic stability. The catalyst represents the...

Two resistance-switchable hybrid polyoxotantalates based on {Co2Ta12} clusters

“…29–31 To date, only a tiny number of POTas have been discovered. 32–47 The reasons for the limited development of POTas include the chemical inertness of the tantalite species, the lack of soluble POTa precursors, the narrow reaction pH range (10–12), the low aqueous solubility of the common [Ta 6 O 19 ] 8− precursor, and the chemical incompatibility between POTas and other metal cations. It is worth noting that POTas have been shown to have significant application value in the fields of virology, photocatalysis, proton conductivity and base catalysis.…”

Solvent-Free Carboxylative Cyclization of CO2 with Alkynol Catalyzed by Ag(I)-Functionalized Polyoxoniobate-Based Coordination Polymer at Room Temperature

“…Bearing these parameters in mind, we intend to design a crystalline catalyst that integrates both Lewis base sites for activating the hydroxyl group and π-Lewis acid sites for activating the CC bond. As a subfamily of polyoxometalates, polyoxoniobates (PONbs) have proven effective in catalyzing the Knoevenagel condensation and the hydrolysis of nerve agent simulant organophosphates, owing to their excellent Lewis base activity. − However, such applications are generally hampered by the high solubility of the original PONbs and their decomposition during the reaction process. A feasible approach to achieving the heterogenization of molecular PONbs and improving their stability is to construct PONb-based inorganic–organic crystalline hybrids.…”