Halogen-aromatic complexes

In agreement with Dewar s proposal (Dewar and Leplay, 1961) and by analogy with the long-established halogen-aromatic molecular complexes... 

Clearly, humans are exposed to a complex mixture of CDDs and other halogenated aromatic hydrocarbons such as chlorinated diben-zofurans (CDF) and polychlorinated biphenyls (PCBs). The toxicological concerns resulting from exposure to mixtures, as well as the gaps... 

PBPK models for 2,3,7,8-TCDD are discussed below. The pharmacokinetic behavior of 2,3,7,8-TCDD, especially distribution, has been shown to be dose-dependent and involves protein binding and enzyme induction in hepatic tissue. Thus, terms describing these interactions have been included in the animal models described below. Furthermore, since induction of these dioxin-binding proteins is a process mediated by the interaction of a dioxin-receptor (the Ah receptor) complex with specific binding sites on DNA additional terms were included in the models. For a detailed explanation regarding the Ah receptor and its involvement in the mechanism of action of 2,3,7,8-TCDD and structurally related halogenated aromatic hydrocarbons, see Section 2.4.2. 

Toxic Equivalency Factors (TEFs) and Toxic Equivalents (TEQs). Humans are exposed to complex mixtures of CDDs and other halogenated aromatic hydrocarbons such as CDFs and PCBs which... 

Henrici-Olive and Olive were the first to put forward the hypothesis that complexes are sometimes formed between the active centre and the monomer and or/solvent [45], As only the complex with monomer is capable of propagation, part of the centres is inhibited and the polymerization rate is reduced. This theory was found to be valid with styrene [46], but not with MMA [47]. Burnett called attention to the important circumstance that radicals solvated in various ways may react differently, or at least at different rates [47]. His conclusions were based on kinetic studies of MMA polymerization in various halogenated aromatics. In the copolymerization of butyl vinyl ether with methacrylates, complex formation between the active centre and condensed aromatics prior to monomer addition was observed by Shaik-hudinov et al. [48], The growing polymer forms a stable donor-acceptor complex with naphthalene, described by the formula. 

Diverse chemicals have been reported to affect measured endpoints of fish thyroidal status. These chemicals include aromatic hydrocarbons, planar halogenated aromatic hydrocarbons (dioxans, furans, coplanar PCBs), organochlorine, organophosphorus and carbamate pesticides, chlorinated paraffins, cyanide compounds, methyl bromide, phenol, ammonia, metals (aluminum, arsenic, cadmium, lead and mercury), low pH conditions, environmental steroids and a variety of pharmaceutical agents. For the following reasons their modes of action appear complex and are poorly understood16. 

LjPt(CF3)X complexes (with L = tetraaryldiphosphines and X = CH CIj, OH, OPh) are hydroxylation catalysts of phenol and phenol ethers, with 70% HjO [46]. In all cases, high ortho-selectivity (up to 95%) is observed. Phenylalanine is hydroxylated by a water-soluble iron porphyrin complex to tyrosine and dihydroxy phenylalanine (DOPA) in good yields [47]. Other hydroxylation catalysts of various aromatic substrates are halogenated porphyrin complexes of Fe and Mn [48-49],... 

A comprehensive ab initio study of geometric and energetic properties of halogen-bonded complexes between two aromatic moieties (pyridine and... 

---