The first ligands to be discovered were synthetic and members of the halogenated aromatic hydrocarbons (polychlorinated dibenzodioxins, dibenzofurans and biphenyls) and polycyclic aromatic hydrocarbons (3-methylcholanthrene, benzo(a)pyrene, benzanthracenes and benzoflavones).
Polychlorinated biphenyl | Polychlorinated dibenzodioxins | Polychlorinated naphthalene | Polychlorinated dibenzofurans | polychlorinated biphenyl |