Structural assignment of a molybdenum-containing silsesquioxane which catalyzes the metathesis of olefins: DPFGSE-NOE and x-ray diffraction studies.

Frank J. Feher, Tsang-Lin Hwang, Joseph J. Schwab, A. J. Shaka, Joseph W. Ziller.

Department of Chemistry, University of California, Irvine, California 92697, USA.


The reaction of [(c-C6H11)7Si7O9(OSiMe3)(OTl)2] with [Mo(CHCMe2Ph)(NAr)(OSO2CF3)2(dme)] (Ar=2,6-diisopropylphenyl) affords 4a as the predominant (>99%) molybdenum-containing product. Assignment of 4a as the syn-isomer with juxtaposed arylimido and Me3Si groups was made on the basis of double pulsed field gradient spin echo (DPFGSE) NOE experiments and confirmed by a single-crystal x-ray diffraction study.