Organometallic compounds, also from alkyl halides

It might be mentioned that matters are much simpler for organometallic compounds with less-polar bonds. Thus Et2Hg and EtHgCl are both definite compounds, the former is a liquid and the latter is a solid. Organocalcium reagents are also known, and they are formed from alkyl halides via a single electron transfer (SET) mechanism with free-radical intermediates. "... 

Carbanions can also be formed from alkyl halides with metals or organometallic compounds. 

Numerous transient paramagnetic compounds are known and some of these are also shown in Table IV there is an overlap with Section V, and Table IV does not duplicate material which is more conveniently treated later. The distinction is arbitrary, but we shall defer consideration of transient transition metal-centered radicals, e.g., Pt(I), if their formation is primarily of interest in connection with an organometallic mechanistic study, e.g., the oxidative addition of an alkyl halide to a Pt(0) substrate. The designation of metal oxidation state in Table IV is somewhat formal in many cases it might be more appropriate to describe a complex as derived from a paramagnetic ligand, such as a nitroxide or ketyl. 

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