Sulphuryl chloride as an electrophile

Abstract

The reaction of sulphuryl chloride with a number of anilides in nitromethane at 25 C has been studied kinetically. It was concluded that although molecular sulphuryl chloride, is the major electrophile molecular chlorine also contributes as the attacking electrophile. [equation] was found; the reaction is kinetically first order with respect to each of the reactants. The effect of the substituents, (p=-5) shows that a heterolyticelectrophilic process is involved. The effect of solvents, which increase the rate of the reaction in the order nitromethane > o-dichlorobenzene> chlorobenzene > benzene, is also evidence for a heterolytic process.The reaction of sulphuryl chloride with anthracene and some of its derivatives, and also with some derivatives of pyrene in chlorobenzene at 25°C has been studied. The stoichiometry of the reaction is [equation]. The only effective electrophile was found to be molecular sulphurylchloride which attacks the ring in the rate determining step. This step is second order, first order with respect to each of the reactants. The magnitude of reaction constant (p -1.73) for anthracenes and p= about -2 for pyrenes indicates that the transition states in these heterolytic processes have acquired some positive charge. The effect of solvent on the rate (o-dichlorobenzene faster than chlorobenzene, which is faster than benzene) also confirms this deduction. The substituent effects show an electrophilic process in which electronic effects appear to be propogated by -electron interactions.