A vinylic halide from an aryl halide?
A vinyl halide is clearly a species with a formula ##H_2C=C(X)H##, in which a halide is directly bound to an olefinic bond. Formally, this is ethylene, ##H_2C=CH_2##, with one of the hydrogens substituted by a heteroatom. Vinyl chloride, ##H_2C=CHCl## is an example. An aryl halide has general formula ##C_6H_5X##, in which an halide group ##X## has substituted the aryl ring. The simplest examples of an aryl halides are bromobenzene or chlorobenzene, ##C_6H_5X##.
Of course, we often represent benzene with a formula of ##”1,3,5-cyclohexatriene”##, but this is a representation rather than an actuality. In an aromatic ring, the ##pi## electrons are conceived to be delocalized around the ring.
