Preparation,Characterization,and Condensation of Copper Tellurolate Clusters in the Pores of Periodic Mesoporous Silica MCM-41

摘要

The copper-tellurolate cluster [(Cu_6(tEpH)_6(PPh_2Et)-5] has been loaded into the pores of MCM-41 by solid-state impregnation techniqus.It was found that the best loading conditions are 110 deg C and 10~(-3) Torr static vacuum.The resulting material was analyzed by powder X-ray diffraction (PXRD0,nitrogen adsorption isotherms,thermogravimetric analysis (TGA),~31P CP MAS NMR spectroscopy,and TEM.It was observed that loading is accompanied by loss of the phosphine shell,with retention of the copper-tellurium core.Condensation of the impregnated matrial may proceed thermally or photochemically.Thermal condensation results in the formation of Cu_2tE nanoparticls as demonstrated by PXRD,and TEM data suggests that the process has taken place inside the pores of MCM-41.Photochemical condensation yields larger metal-chalcogen clusters in the pores as suggested by the result of UV-Vis diffuse reflectance spectroscopy and TEM measurements.