Electronic factors affecting receptor binding of dibenzo‐p‐dioxins and dibenzofurans

The electronic structure of a series of 25 chlorinated dibenzo‐p‐dioxins and dibenzofurans has been characterized by means of the ab initio molecular fragment technique. This information has been employed to investigate some of the factors affecting the affinity of the molecules for the hepatic cytosol binding species described by Poland, Glover, and Kende. A quantitative structure–activity relationship involving electronic and steric parameters could be established from the data. It appears that the toxins act as electron acceptors in a charge‐transfer complex with the receptor.