Exhaustive chlorination as a technique in the analysis of aromatic hydrocarbons

Perchlorination reactions of aromatic compounds have been further investigated. The preparation and properties of decachlorodiphenyl ether and the isomeric o-, m-, and p- tetradecachloroterphenyls are described. Anthracene, as an example of a polycyclic aromatic hydrocarbone, gave octachloranthraquinone when treated with the antimony pentachloride iodine reagent, but quantitative conversion to decachloranthracene could not be obtained with reagent BMC (sulfuryl chloride aluminum chloride sulfur monochloride). A new reagent, trichlorosulfur tetrachloraluminate (SCl₃⁺ AlCl₄^-), was shown to convert Aroclor 1254 to decachlorobiphenyl. As an application of the perchlorination technique it was shown that polychlorodibenzofurans (dibenzofuran) are not present at 0.5 μg/g in samples of Halowax 1014 and technical naphthalene, respectively. Well defined derivatives could not be obtained when phthalate esters or 'hexabromobiphenyl' (fireMaster BP 6) were treated with BMC or SbCl₅ I₂ reagents.