Aryl mercury compounds

Toxicity. Inorganic mercury compounds, aryl mercury compounds, and alkoxy mercurials are generahy considered to be quite similar in their toxicity. Alkyl mercury compounds are considered to be substantiahy more toxic and hazardous. Mercury and its compounds can be absorbed by ingestion, absorption through the skin, or by inhalation of the vapor. The metal itself, however, rarely produces any harmful effects when ingested (16). 

The exchange of mercury between alkyl and aryl mercury compounds equilibria (282)-(284)... 

Warfarin, diphenacoum, bromodiolone, flocoumafen, and brodiphacoum are examples Both alkyl and aryl mercury compounds can bind to sulfhydryl groups Have caused population declines in certain mollusks... 

Cappon and Crispin-Smith [59] have described a method for the extraction, clean-up and gas chromatographic determination of alkyl and aryl mercury compounds in sediments. The organomercury compounds are converted to their chloroderivatives and solvent extracted. Inorganic mercury is then isolated as methylmercury upon reaction with tetramethyltin. The initial extract is subjected to a thiosulphate clean-up and the organomercury species are isolated as their bromoderivatives. Total mercury recovery was in the range 75-90% and down to lpg kg-1 of specific compounds can be determined. 

The 2003 ACGIH threshold limit valuetime-weighted average (TLV-TWA) for elemental and inorganic mercury is 0.025mg/m as Hg, and for aryl mercury compounds is... 

The use of mercury has the merit of easy preparation of the aryl mercury compounds directly from the aromatic compound and an inorganic mercury salt, sometimes in complete regioselective manner. Preparation of the other metallated species generally involves more synthetic steps. An example of a radiofluorode-mercuration reaction (Scheme 29) is the synthesis of 6-p F]fluorometaraminol... 

As illustrated in Schemes 4.1.4 through 4.1.9, the use of pyrimidinyl mercuric acetates have been instrumental in the development of C-nucleosides. Although the comparison in Scheme 4.1.9 illustrates the utility of aryl iodides in addition to aryl mercury compounds, the nature of the specific reagents were quite different. As shown in Scheme 4.1.11, Zhang, etal.,10 utilized pyrimidinyl iodides in the preparation of C-nucleosides from furanose glycals. As illustrated, the product mixture composition was highly susceptible to the specific reaction conditions used. Thus, of the two products shown, either is available in comparable yields. 

The sensitivity of plants to mercury compounds are different. In general, the fungitoxic concentration does not harm the seeds and bulbs of the plants the therapeutic index of mercury compounds for seed treatment is therefore satisfactory. Potato seed is an exception because it is susceptible to many species. However, only aryl mercury compounds are suitable for foliage application, and these only in the case of certain plants or in certain stages of development. Thus, phenylmercury acetate or chloride are not phytotoxic to apple trees in the prebloom period. Arylmercury compounds are not phytotoxic to the rice plant at all. Phytotoxicity is mainly caused primarily by mercury vapours formed on the reduction of mercury compounds (Hitchcock and Zimmermann, 1957). According to Lee et at. (1973), mercury compounds inhibit the biochemical reactions of the electron transport of photosynthesis, depending on the pH value and on the concentration. 

Unsymmetrical diaryl-, dialkyl-, and alkyl(aryl)-mercury compounds are conveniently prepared by reaction of organomercuric halides with the necessary Grignard reagent 170... 

Alkoxyalkyl and aryl mercury compounds appear to be quickly metabolized to inorganic mercury by biological systems. As a result, symptoms of intoxication are similar to those associated with inorganic mercury salts (Roberts et al. 1979, Pfab et al. 1996, Graeme and Pollack 1998). 

A study of the effect of halide ions on the oxidative addition of Phi to electrogenerated Pd(PPh3)2 showed that three halide complexes were present in equilibrium. xhe addition of Phi to [PdL4] [L = PPh3, P(2-furyl)3] has been studied by 3lp NMR, and the rate of oxidadve addition of aryl mercury compounds to [Pd(PPh3)4] has been measured electrochemically. ... 

DIALKYL AND ARYL MERCURY COMPOUNDS AND ALKYL AND ARYL MERCURY HALIDES... 

Lithium reagents can trace their roots back almost 100 years to the pioneering work of Wilhelm Schlenk [2, 3], who initially prepared ethyllithium, propylUthium and phenyUithium from the corresponding alkyl/aryl mercury compound and lithium metal (Fig. 1.) [4]. 

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