COMPLEX FORMATION BETWEEN PROPARGYL CHLORIDE AND BENZENE

Publisher Website
Google Scholar
Abstract
The proton resonance signals of the methylene and ethynyl hydrogens in propargyl chloride shift upfield in going from cyclohexane to benzene as solvent. This is interpreted as being due to complex formation between propargyl chloride and benzene. Though the methylene proton resonance signal shifts farther upfield than does the ethynyl proton resonance signal, it is found that only a 1:1 complex exists between the two molecules. The complex is considered to be one in which the methylene protons "bond" to the π-electron system of the benzene ring. The ethynyl proton of the propargyl chloride is thought to lie close enough to the ring to interact with the "ring current", but not close enough to be a prime agent in complex formation.