Organozinc Compound

Organozinc Compound

Organozinc compounds in organic chemistry contain carbon to zinc chemical bonds. Organozinc chemistry is the science of organozinc compounds describing their physical properties, synthesis and reactions.

The first organozinc compound ever prepared, diethylzinc (by Edward Frankland in 1849), was also the first compound discovered with a metal-to-carbon sigma bond. Many organozinc compounds are pyrophoric and therefore difficult to handle. Organozinc compounds in general are sensitive to oxidation, dissolve in a wide variety of solvents where protic solvents cause decomposition. In many reactions they are prepared in situ, not isolated and reacted further. All reactions require a protective gas (nitrogen or argon) blanket.

The most common oxidation state is +2. The three main classes of organozincs are: organozinc halides R-Zn-X with X a halogen atom, diorganozincs R-Zn-R with R an alkyl or aryl group and lithium zincates or magnesium zincates M+R₃Zn- with M lithium or magnesium.

The carbon zinc bond is polarized towards carbon due to the differences in electronegativity (carbon:2.55 and zinc: 1.65). Diorganozincs are always monomeric, the organozinc halides form aggregates through halogen bridges very much like Grignard reagents and also like Grignards they display a Schlenk equilibrium.