Variety, structures, GC properties, and persistence of compounds of technical toxaphene (CTTs)

General limitations on the variety of chlorinated bornanes due to steric and energetic aspects are presented. The empirical rules were supported by spectroscopic and semiempirical calculations. It was found that a dichloromethyl substituent on C8 requires a 6-exo chlorine atom and a dichloromethyl group on C9 requires a 2-exo chlorine atom. The relevance of energetically optimal conformations on C8, C9, and C10 is discussed. It was shown that the different conformations are not relevant for the nomenclature of polychlorinated bornanes and that atropisomers are not likely to exist at physiological temperatures. On the other hand, the optimal conformers discussed earlier by Parlar seems to be one of the key factors that lead to persistence.