The types of organozinc compounds are introduced as follows:
1. Hydrocarbyl zinc
Alkyl zinc includes dihydrocarbyl zinc R2Zn and monohydrocarbyl zinc RZnX (X=halogen, H, OR, SR, NR2, etc.)
1. Preparation: The product dialkyl zinc can be distilled out by reacting iodinated hydrocarbons with zinc metal. Diarylzinc Ar2Zn can be prepared by reacting Grignard reagent and anhydrous zinc chloride in diethyl ether.
2. Physical properties: Dihydrocarbyl zinc is a linear molecule. The hydrocarbyl group and zinc are combined with σ bonds, and zinc hybridizes with carbon atoms in sp hybrid orbitals. Tracks overlap.
3. Chemical properties:
①Dialkyl zinc: chemical properties are relatively different It is stable, relatively lively, and can spontaneously ignite in the air.
If the dialkyl zinc reacts with an alcohol containing active hydrogen, a hydrocarbyl zinc alkoxide will be generated, which is generally a colorless solid and can be dissolved in polar and non-polar solvents. It is associated either in the crystal or in the liquid state, which is a classic structure of a cube.
②Zinc Grignard reagent: If compared with the typical Grignard reagent organomagnesium, it can be found that organic zinc Under normal circumstances, it does not react with carbon dioxide, but organomagnesium does. This is the difference in activity between the two. Speaking of Grignard reagents, perhaps Organozinc is most noteworthy for the reactions it participates in Rivermarski reaction.
③Alkyl zinc iodide: Alkyl zinc iodide is relatively stable and does not spontaneously ignite in the air, so alkyl zinc iodide can be stored for a short period of time. In addition to being a Grignard reagent, Another wonderful reaction of organozinc is the Simmons-Smith reagent appeared at the time. Simmons-Smith reagent is a reagent in which the methyl hydrogen of methyl zinc iodide is replaced by I, namely ICH2ZnI. It is synthesized from diiodomethane and Cu-Zn alloy in diethyl ether. Cu among them is considered as activator. Copper-zinc alloy is prepared directly when used. It is prepared from zinc powder and CuCl in ether under nitrogen protection. After preparation, CH2I2 is directly added in situ to generate ICH2ZnI.
