Olefin complexes of rhodium

Todd et al. (24) measured Jwrh-c of 10 to 16 Hz and substantial upheld shifts (50 to 115 ppm) of the olefinic carbons in a series of rhodium-olefin complexes. A value of 15% character in the rhodium-olefinic carbon bond was calculated from the Rh-C coupling constants. The estimate of 15%. s character implied approximately 60% contribution of the bonding form in which there is a ct bond between an sp rehybridized olefinic carbon and a dsp rhodium orbital. 

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