Oxovanadium(IV) and dioxomolybdenum(VI) salen complexes tethered onto amino-functionalized SBA-15 for the epoxidation of cyclooctene

摘要

Oxovanadium(IV) and dioxomolybdenum(VI) salen complexes were firstly tethered onto amino-functionalized mesoporous SBA-15 materials by a stepwise procedure and were screened as catalysts for the epoxidation of cyclooctene. The mesoporous structural integrity throughout the tethering procedure, the successful tethering of the organometallic complexes, the loadings of metal ions and organic ligands as well as the catalyst surface constitution and location of active organometallic species on the SBA-15 support were determined by comprehensive characterization techniques such as XRD, N_2 adsorption/desorption, FT-IR, UV-vis spectroscopy, ICP-AES, XPS and TG/DTA. Catalytic properties in the epoxidation of cyclooctene demonstrate that both tethered oxovanadium(IV) and dioxomoIybdenum(VI) catalysts were more active than their respective homogeneous analogue, and the tethered oxovana-dium(lV) complex showed the best activity (64.3%) with H_2O_2 as the oxidant and CH3CN as the solvent.