Alkaline Earth-Tuned Polyoxometalate Frameworks: Enhanced Selectivity in Styrene Epoxidation

Two novel compounds based on high-nuclear metal-oxygen clusters, copper-amine complexes and alkaline earth metals were successfully synthesized under hydrothermal conditions, with chemical formulae [Cu(en)2]3.5Ba2[H2K0.5SiNb18O54]‧18H2O (1) and [Cu(en)2]5Ba2K2[H13K2Nb31O93]‧24.5H2O (2) (en=ethylenediamine), respectively....