文摘
[WOCl4] was grafted on silica dehydroxylated at 200 掳C, and the structure of the surface species was elucidated by a combination of spectroscopic and theoretical methods, demonstrating the formation of [(鈮iO)2WOCl2] (1a) as the major species accompanied by minor monopodal species [(鈮iO)WOCl3] (1b). Most noteworthy, EXAFS and 17O NMR combined to DFT calculations helped elucidate the structure of the surface species. Alkylation was performed using SnMe4, affording methyl species that were also precisely characterized. The alkylated species achieved excellent performances in isobutene metathesis to 2,3-dimethylbutene.
Keywords:
metathesis; surface chemistry; tungsten; tin; alkylation