Allyl And Vinyl Halides

An allylic halide is an alkyl halide in whose molecule there are one or more halogen atoms on allylic carbons.

Allyl and vinyl halides. Vinyl chloride h 2c ch cl is an example. For 3º halides a very slow s n 2 substitution or if the nucleophile is moderately basic e2 elimination. The general molecular formula for allyl is rch 2 ch ch 2 whereas the general molecular formula for vinyl is rch ch 2. Key difference allyl vs vinyl both allyl and vinyl groups have slightly similar structures with a small variation.

Rapid s n 2 substitution for 1º. From the perspective of applications the dominant member of this class of compounds is vinyl chloride which is produced on the scale of millions of tons per year as a precursor to polyvinyl chloride. Iitian faculty explains the above concept in entertaining and conceptual manner. Likewise phenyl cations are unstable thus making s n 1 reactions impossible.

It consists of a methylene bridge ch 2 attached to a vinyl group ch ch 2. In addition the carbon halogen bond is shorter and therefore stronger in aryl halides than in alkyl halides. Allyl group holds three carbon atoms and five hydrogen atoms on the other hand vinyl group has two carbon atoms and three hydrogen atoms. Polyvinyl fluoride is another commercial product.

The key difference between these two structural components is the number of carbon and hydrogen atoms. Steric hindrance caused by the benzene ring of the aryl halide prevents s n 2 reactions. Aryl halides or haloarenes in aryl halides the halogen atom is directly bonded to an sp2hybridised carbon of benzene. For this reason alkenyl halides with the formula rch chx are sometimes called vinyl halides.

The carbon halogen bond is shortened in aryl halides for two. In high dielectric ionizing solvents such as water dimethyl sulfoxide acetonitrile s n 1 and e1 products may be observed. An aryl halide has general formula c6h 5x in which an halide group x has substituted the aryl ring. Allyl h 2 c chch 2 rapid s n 2 substitution for 1º and 2º halides.

The simplest examples of an aryl halides are bromobenzene or chlorobenzene c6h 5x.