Methyltrioxorhenium Encapsulated in Zeolite Y:  Tunable Olefin Metathesis Catalyst

Methyltrioxorhenium (MTO) was encapsulated in different forms of zeolite Y having a range of acidity levels. EXAFS and vibrational studies show that at room temperature, the complex maintains its integrity in the hosts. The MTO−zeolite adducts are active in the metathesis of 1-hexene at room temperature, in competition with double-bond isomerization and secondary metathesis products. Strong acidity of the host favors isomerization. The MTO molecule is activated by the intrazeolite protons and simultaneously blocks their isomerization activity.