The binding of two organohalogen substances, pentabromophenol (PBP) and 2,4,6-tribromophenol (TBP), to human transthyretin (TTR), a thyroid hormone transport protein, has been studied by in vitro competitive binding assays and by X-ray crystallography. Both compounds bind to TTR with high affinity, in competition with the natural ligand thyroxine (T(4)). The crystal structures of the TTR-PBP an...

Sudden depletions of tropospheric ozone during spring were reported from the Arctic and also from Antarctic coastal sites. Field studies showed that those depletion events are caused by reactive halogen species, especially bromine compounds. However the source and seasonal variation of reactive halogen species is still not completely understood. There are several indications that the halogen mo...

Halogens in the troposphere are increasingly recognized as playing an important role for atmospheric chemistry, and possibly climate. Bromine and iodine react catalytically to destroy ozone (O3), oxidize mercury, and modify oxidative capacity that is relevant for the lifetime of greenhouse gases. Most of the tropospheric O3 and methane (CH4) loss occurs at tropical latitudes. Here we report sim...

Five halogen substituted pyrazolates, 4-chloro-3,5-diisopropylpyrazole (4-Cl-3,5-iPr2pzH), 4-bromo-3,5-diisopropylpyrazole (4-Br-3,5-iPr2pzH), 4-iodo-3,5-diisopropylpyrazole (4-I-3,5-iPr2pzH), 4-chloro-3,5-diphenylpyrazole (4-Cl-3,5-Ph2pzH), and 4-bromo-3,5-diphenylpyrazole (4-Br-3,5-Ph2pzH), were conveniently prepared by halogenation of the appropriate pyrazoles with N-halosuccinimides (NXS) (...

Thirty-six halogenated Me Et ethers have been synthesized for evaluation as volatile anesthetics. Eleven of the ethers were too unstable to test, and, of the remaining 25, 13 had promising anesthetic properties in mice and are suitable for study in larger animals. Those ethers having one H with at least 2 halogens other than F or 2 or more H with at least one Br or Cl were the best anesthetics.

The first total synthesis of (+/-)-chartelline C in a concise 10-step sequence is reported. Highlights of the completion of this decades-old puzzle include (1) chemo- and position-selective installation of the heteroaromatic halogens, (2) halogen-sparing monoreduction of an alkyne linker, (3) a simple strategy for placement of the sensitive beta-chloroenamide, (4) an unusually facile thermolysi...

A. Organic Analyses 218 1. General Organic Analyses 218 2. Pesticides 219 3. PAHs and PCBs 221 4. Dioxin 222 5. VOCs 223 6. Textile Dyes 223 7. Surfactants 223 8. Disinfection Byproducts 224 9. Taste and Odor Compounds 226 10. Algal and Bacterial Toxins 226 11. Other Organic Pollutants 227 B. Inorganic Analyses 229 1. Disinfection Byproducts 229 2. Perchlorate and Dissolved Gases 230 3. Multipl...

Chlorella pyrenoidosa was found to grow rapidly in tap water. Peak growth was reached after 2 to 3 days. Chlorine and bromine, added to such water, were shown to be effective inhibitors of algal growth. Bromine and bromamine were primarily algicidal, whereas chlorine and chloramines were mainly algistatic. It is assumed that the mechanisms of action of these halogens on Chlorella are not the same.

Volatile emissions to the atmosphere associated with Siberian Traps eruptions at Permian-Triassic boundary were sourced from outgassing of primary magmas and sedimentary host rocks into which they intruded. Halogens in volcanic gases may have played an important role environmental degradation stratospheric ozone destruction. Here we investigate how halogens behave during interaction between sal...

Addition of ammonium acetate fo llowed by commerc ial zinc dust to the solution of azo compounds in methanol appcars to o ffer a general and convenient mea ns for reducing bot h sym metri ca l and unsymmetrical azo compounds to the corresponding amine/s at ambient temperature. Many other reducible and hydrogenolysable groups like -OCH1. -OH. -COOH, -CH1• -COCH) and halogens are to lerated. The ...