Mercury compounds except

Seyferth, D. 1972. Phenyl(trihalomethyl)mercury compounds. Exceptionally versatile dihalocarbene precursors. Acc Chem Res 5, 65-74. 

Mercury compounds [except (organo) alkyls] (as Hg) Formula Hg (metal) CAS 7439-97-6 (metal) RTECS OV4550000 (metal) IDLH 10 mg/m (as Hg)... 

CH3 -Zn with superstoichiometric (defect) zinc atoms (Zn -impurity centres of conductivity). The larger is the electric positivity of the metal in these complexes, the larger is the ionicity of the carbon-metal bond, carbon being at the negative end of the dipole. Thus, in the case of C - K bond, ionicity amounts to 51%, whereas for C - Mg and C - Zn bonds ionicity amounts to 35% and 18%, respectively [55]. Consequently, metalloorganic compounds are characterized by only partially covalent metal-carbon bonds (except for mercury compounds). 

Phosphoryl radicals [10, 18, 38-42] tend to add to double bonds. Owing to the exceptionally high constants of hyperfine coupling of the unpaired electron with the phosphorus nucleus, phosphoryl radicals can be utilized as paramagnetic reporters [10]. Phosphoryl radicals have been prepared by photolysis of diphosphoryl mercury compounds (Scheme 6.5). 

The - electrochemical window of polished solid silver amalgam electrode (p-AgSAE) as for an electrode which does not contain liquid mercury is exceptionally broad. This fact allows the application of p-MeSAE for determination of species at rather negative potentials. An important advantage is that the electrodes from solid amalgams of different metals can be prepared in a relatively simple way, and that in their applications specific interactions between these metals and the studied compounds can be utilized. 

In alkaline media all the above compounds, except for Ar4Pb or Ar2PbCl2, formed ArjHg almost instantaneously when treated with mercury dichloride (or mercuric oxide) (54). The compound ArB(OH)2 behaved similarly. RHgOri could be arylated in alkaline media in the same fashion thus a new synthesis of unsymmetric RHgAr compounds was ready for use (Freidlina, Kocheshkov, Nesmeyanov) (55). 

The fact that irradiation of disilanes la - 3a did not produce detectable products other than the corresponding silyl radicals indicates that the radicals produced photochemically undergo clean recombination to produce the starting silane, as shown in Scheme 5 path (b). An exception is the photochemical reaction of silyl mercurial compounds 4c, which produce the hydrosilane 6 [Scheme 5, path (c)], while the corresponding dimer 4a [Scheme 5, path (b)] is not detected. Apparently, for radical 4b, hydrogen abstraction to produce silane 6 occurs significantly faster than its dimerization to 4a. 

Inorganic mercury compounds occur when mercury combines with elements such as chlorine, sulfur, or oxygen. These mercury compounds are also called mercury salts. Most inorganic mercury compounds are white powders or crystals, except for mercuric sulfide (also known as cinnabar) which is red and turns black after exposure to light. 

Studies of the kinetics of methylmercury after ingestion showed that its distribution in the tissues is more homogenous than that of other mercury compounds, with the exception of elemental mercury. 

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. 

Well defined higher metallated organomagne-siuni compounds are not known with two remarkable exceptions the dimeric pentamagnesiaied ru-thenoeene 154 and the deeamagnesiated rutheno-ecne 155. both obtained from the corresponding mercury compounds by treatment with meihylmag-nesium chloride 1105] (Scheme 1.40). 

Mercury Species in the Environment Most of the mercury encountered in water/ soil/sediments/biota (all environmental media except the atmosphere) is in the form of inorganic mercuric salts and orga-nomercurics. The presence of a covalent C—Hg bond differentiates organomercurics from inorganic mercury compounds that merely associate with the organic material in the environment but do not have the C—... 

Note All values, except for the L/C ratios, are the yields of products given in millimoles. In runs 1-4, 2.50 mmol of Th +Cl()4 reacted with 1.00 mmol of (5-hexenyl)2Hg in run 5, 0.5 mL of 12 N HC1 reacted with 1.0 mmol of (5-hexenyl)2Hg. The mixture of isomers of (5-hexenyl)2Hg is described in the Experimental Details. After reaction with the mercurial compound was finished in runs 1-4, the products were treated with LiCl (see Experimental Details). This reaction converted ions such as ThR+ into Th and RC1, and RHg+ into RHgCl. This situation accounts for such halides being listed in column 1. aSum of isomeric compounds having M+ (GC-MS) of 298. feSum of isomeric compounds having M + (GC-MS) of 380. 

Mercury compounds, as Hg [except (organo) alkyls] Hg Vapor TWA 0.05 mg/m [skin] Non-alkyl compounds C 0.1 mg/m [skin]... 

The first in situ Raman spectroscopic study on electrochemical systems was reported on thin metal oxide and metal hahde film electrodes by Fleischmann etal. in 1973 [1]. The Raman spectroelectrochemi-cal measurements were made on thin films of Hg2Cl2, Hg2Br2, and HgO formed on droplets of mercury electrodeposited onto platinum electrodes. These mercury compounds have exceptionally high Raman scattering cross sections (very good Raman scatterers) so that the spectra of species as little as a few monolayers could be recorded on these high-surface-area electrodes. These experiments proved the viability of Raman spectroscopic measurements of... 

CELLULOID, in blocks, rods, rolls, sheets, tubes, etc except celluloid scrap 2025 53 MERCURY COMPOUNDS, sdid. n.o.s. 

Mercury compounds are more soluble in concentrated HNO3 than in water or the dilute acid. Nitric acid dissolves all common insoluble compounds of mercuiy except HgS, which, however, may be converted to the more soluble complex Hg3S2(N03)2, white, by boiling with concentrated acid. All dimercury(I) salts are oxidized to mercury(II) compounds by excess of HNO3. 

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