Organomercurials cadmium metal

In this section, we will discuss organometallics in which the metal is cadmium, mercury, or zinc. Grignard reagents and organolithium compounds can be converted to heavy-metal derivatives by reaction with salts of these metals. The reaction is driven forward by the tendency for formation of the ionic salt of the more electropositive metal. This reaction is well documented for organocadmium compounds and organomercurials ... 

Linear organomercurials provide a convenient basis for the investigation of the effect of susbstitution in the organic moiety on the metal chemical shift. Increase in the shielding of 150 ppm are observed for each substitution of Me for a H in Hg-CH3 derivatives, while smaller decreases in shielding ( 30 ppm) occur on substitution of )S-Hs. Cadmium alkyls show a similar behavior, but for silyl mercury compormds, replacements at both a and position results in deshielding. 

---