Mercury compounds, aromatic

The conversion may consist simply in oxidation or be the result of a more complex reaction. For example, nitrosotoluene can be converted into diazonium nitrate under the influence of nitrous acid. Bamberger [132] found in 1918 that nitrosobenzene could be converted into benzenediazonium nitrate under the influence of nitrous acid. According to Bamberger [133] and Nesmeyanov [134], mercury-aromatic compounds also give nitrates of corresponding diazonium compounds under the influence of N203, presumably also through nitroso compounds. 

Mercury, aromatic compounds of types, R Hg, BHgR, RHgX, 69,... 

The dosimeter can detect various polynuclear aromatics at the pph level after 1 hour of exposure. It has been shown that the RTF of aza-arenes can he enhanced by using mercury(II) chloride as a heavy atom (21). Also, sensitized fluorescence spectrometry with a solid organic substrate can be used to detect trace amounts of polynuclear aromatic compounds (22). 

Photolytic. Synthetic air containing gaseous nitrous acid and toluene exposed to artificial sunlight (Z = 300-450 nm) yielded methyl nitrate, peroxyacetal nitrate, and a nitro aromatic compound tentatively identified as a nitrophenol or nitrocresol (Cox et al., 1980). A n-hexane solution containing toluene and spread as a thin film (4 mm) on cold water (10 °C) was irradiated by a mercury medium pressure lamp. In 3 h, 26% of the toluene photooxidized into benzaldehyde. 

The electron spin resonance spectra were run in nitrogen-saturated solutions of aromatic compound ca. 10" m) and nucleophile (0-05-0-1 M) in the solvent(s) indicated. Irradiation in the cavity was effected with a high pressure mercury arc. Electrolysis was performed with the platinum cathode in the cavity, tetraethyl-ammonium perchlorate as electrolyte and electric currents of 10-250 /lA. 

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... 

Recently, Japaridze etal. [170] have investigated adsorption of some aromatic compounds, including naphthalene, naphthonitrile, naphthylamine, anthracene, and phenathrene at the mercury electrode I ethylene glycol solution interface. The analysis of the differential capacity data obtained at the HMDE has revealed that adsorption of the above-mentioned compounds obeys the Frumkin model, with attractive interactions of the particles in the adsorption layer. The results for ethylene glycol were compared with those for other nonaqueous solvents and their role in determining the adsorption mode was discussed. 

WOLFFENSTEIN-BOTERS REACTION. Simultaneous oxidation and nitration of aromatic compounds to nitrophcnols with nitric acid or the higher oxides of nitrogen in the presence of a mercury salt as catalyst. Hydroxynitration of benzene yields picric acid. 

Nitric acid and organic and inorganic nitrates, and in general all substances which contain free nitric acid or yield nitric acid when they are treated with concentrated sulfuric acid, are analyzed by means of the nitrometer. The method depends upon the measurement of the volume of the nitric oxide which is produced when concentrated sulfuric acid acts upon the sample in the presence of mercury. It is satisfactory also for the determination of nitro group nitrogen in certain nitroamines, in nitro-guanidine and in tetryl but not in methylnitramine. It is not satisfactory in the presence of mononitro aromatic compounds or of other substances which are nitrated readily by a solution of nitric acid in concentrated sulfuric acid. 

Electrochemical studies are usually performed with compounds which are reactive at potentials within the potential window of the chosen medium i.e. a system is selected so that the compound can be reduced at potentials where the electrolyte, solvent and electrode are inert. The reactions described here are distinctive in that they occur at very negative potentials at the limit of the cathodic potential window . We have focused here on preparative reductions at mercury cathodes in media containing tetraalkylammonium (TAA+) electrolytes. Using these conditions the cathodic reduction of functional groups which are electroinactive within the accessible potential window has been achieved and several simple, but selective organic syntheses were performed. Quite a number of functional groups are reduced at this limit of the cathodic potential window . They include a variety of benzenoid aromatic compounds, heteroaromatics, alkynes, 1,3-dienes, certain alkyl halides, and aliphatic ketones. It seems likely that the list will be increased to include examples of other aliphatic functional groups. 

Classes of organic compounds analysed by this technique include non ionic surfactants, fatty acids, hydrocarbons (all types), organochlorine compounds, organosulphur and phosphorus compounds, substituted aromatic compounds, NT A, EDTA and insecticides and herbicides. Organometallic compounds studied include those of arsenic, lead, germanium, mercury and tin. 

The preparation of organopalladium compounds by exchange reactions of palladium salts and organo-lead, -tin, or -mercury compounds is apparently not the only way that they can be obtained but it does seem to be the most useful way. Convincing evidence is now available to show that direct metalation of aromatic compounds with palladium salts (palladation) can occur. Since the initial report of Cope and Siekman 32> that palladium chloride reacted readily with azobenzene to form an isolable chelated, sigma-bonded arylpalladium compound, several additional chelated arylpalladium compounds have been prepared. 

Acetyl hypofluorite also cleaves the carbon-mercury bond which provides an easy entry to many fluoroethers. Since the electrophilic fluorine attacks the electrons of the C—Hg bond, the reaction proceeds with a full retention of configuration. Several l-fluoro-2-methoxy derivatives were prepared from the corresponding olefins271, formally accomplishing the addition of the elements of MeOF across a double bond (equation 153)272. Such reactions were also used for the fluorination of very activated aromatic compounds (equation 154)273. 

Mercury to carbon bonds can be formed by the reaction of certain mercury(II) compounds, especially the acetate, trifluoroacetate, or nitrate, with olefinic or aromatic organic molecules. 

Mercury Derivatives of Aromatic Compounds containing Halogen, Nitro, or Sulphonic Acid Groups. 

Another study assessed immunological effects in juvenile C57B1/6 mice that were fed diets containing no fish or 33% coho salmon from Lake Ontario or the Pacific Ocean for 2-A months (Cleland et al. 1989). Intakes of persistent toxic substances were not reported although the halogenated aromatic hydrocarbons with the highest concentrations in the control chow. Pacific salmon diet, and Lake Ontario salmon diet were total PCBs (0.4, 20, and 2,900 ppb, respectively) and p,p-DT)C (0.1, 10, and 670 ppb, respectively). Levels of PCDDs and PCDFs, mercury, tin compounds, and other metals were not examined. 

The threshold density is that density of solvent gas at which a solute begins to dissolve in a supercritical fluid (or dense gas) at levels that are detectable (11). In Bowman s work it was UV detection using a mercury lamp for aromatic compounds the solute solubilities corresponding to threshold densities of carbon dioxide were on the order of micrograms-to-nanograms per milliliter of carbon dioxide. 

Corrections for the (j)2 effect can be made most readily for the mercury electrode, since the variation of with E and electrolyte concentration can be obtained from electrocapillary curves, as discussed in Section 13.2. In the absence of specific adsorption of electrolyte, (f)2 can then be calculated by assuming that the GCS model applies [from (13.3.26)]. Such corrections are less frequently attempted at solid electrodes because data about the doublelayer structure at them is often lacking. Typical results showing such corrections for the reduction of Zn(II) at a Zn(Hg) electrode in aqueous solution (58) and for the reduction of several aromatic compounds in MA -dimethylformamide solution (65) are given in Table... 

---