Mercury complex compounds

Due to the relatively high acidities of their hydroxy groups, hydroxyazoles readily exchange their protons with metal ions, which leads to stabilization of metal derivatives of the hydroxy tautomeric forms in metal coordination compounds of 2(5)-oxoazoles [97UK434 98AHC(72)1]. A typical example is the mercury complex 361 [93JCS(D)1003]. 

In a first part, experimental methods for studying formation, properties, structures and bonding in complex compounds of cadmium and mercury are briefly surveyed, usually with hints to reviews of the respective field and to examples of recent applications. 

In the main part, dealing with complex compounds of cadmium and mercury, those with complicated organic ligands are not considered, neither are complexes with bio-relevance systematically described. However, it is unavoidable to address the formation of frameworks with the metals and certain organic ligands, and even seemingly simple compounds like Cd(CN)2, especially in the presence of appropriate guest molecules, tend to form wide-pore host frameworks. 

STRUCTURES AND BONDING IN COMPLEX COMPOUNDS OF CADMIUM AND MERCURY... 

Herrmann has reported the reaction of the mercury diazo compound Hg(CN2C02Et)2 with Mn(CO)sBr to afford the biscarbyne-bridged dimer 90 (128). The intermediacy of a terminal mononuclear carbyne complex 89 is strongly implicated here ... 

Organic compounds such as terminal alkynes can undergo direct mercuration using various mercury salts. For instance, alkyne 61 has been shown to react with Hg(OAc)2 to form the symmetrical bis-alkyl-mercury complex 62 (Equation (21)).73... 

These reactions are compared with those of the equivalent 1-alkenyl HgCl compounds. Some differences are observed, notably that the mercury complexes will react with PhSe—SePh, while the tin complexes undergo no reaction at all. The reactions with ChHg, QHgCl and RHgCl, however, are broadly similar to that shown in reaction 26. 

Kouwenhoven (6) sjmthesised two bis-olefinic ligands related to the simple pent-4-enyl compounds mentioned above. These were of the general formula PhD[(CH2)aCH =CH2]2 (D = P, As) and formed platinum(II) and mercury(II) complexes. The platinum complexes LPtCla (L = PhD[(CH2)3 CH=CH2]2) were found to be monomeric species containing, as shown by their i. r. spectra, one coordinated and one free double bond. The two mercury complexes [LHgClaJs did not contain coordinated olefinic groups. 

Organolithium compounds, 2 69 ring stacking, 37 82-92 systems capable of, 37 82-83 uncomplexed, structure, 37 53-54 X-ray crystal structure, 37 48 Organomagnesium halides, 2 71 Organomercury compounds, see Mercury, -carbon compounds Organometallic complexes... 

Mercuric chloride in methanol also reacts with compounds 8 (in dichloro-methane), forming colorless mercury complexes, which can in turn be reconverted to the cyanines 8. Such addition compounds are stable only as solids, decomposing rather quickly in solution. Mercuric acetate in methanol reacts rapidly with the formation of elemental mercury, where by the phosphamethin-cyanines are destroyed uniform products from this reaction have not as yet been isolated. 

Azoalkanes have also been produced by oxidation with mercuric oxide. This reagent is considered the reagent of choice for azoalkanes [76, 87, 93], as well as for the preparation of cyclic azo compounds [94], and 1-pyrazolines [95a]. When used in the preparation of a-carbonyl azo compounds, evidently mercury complexes are formed with the diacylhydrazine starting materials. These complexes are then treated with halogens (iodine or chlorine) to produce the azo compounds [92]. 

The ammonium salts seem to form a special series of a different type to most of the other salts. This is connected with the general tendency of ammonium salts to form complex compounds, which in turn depends upon the peculiar properties of nitrogen—the mercury-ammonia compounds can be cited in illustration. Similar remarks apply to the ferro- and ferri-cyanides, etc. 

Figure 13 Structure of the mercury(II) complex compound Hg2(PPh3)2(0H)(C104)3-egdm...

Nearly all nitrogen donor compounds form complexes of variable composition with mercury(II) compounds of all kinds. Since the literature of these coordination compounds of mercury(II) is listed up to May 1975 in McAuliffe s book,7 only some new complexes will be mentioned here. +... 

The preparations given below are representative examples of the synthesis of mercury chalcogenolato compounds by several different routes and apply particularly to the preparation of monomeric, sterically highly hindered complexes. 

Mercury fulminate dissolves readily in an aqueous solution of potassium cyanide to form a complex compound from which it is reprecipitated by the addition of strong acid. It dissolves in pyridine and precipitates again if the solution is poured into water. A sodium thiosulfate solution dissolves mercury fulminate with the formation of mercury tetrathionate and other inert compounds, and this reagent is used both for the destruction of fulminate and for its analysis.10 The first reaction appears to be as follows. 

Following the preparation of 4.79, a number of other cyclic mercury crown compounds have been synthesised, which do exhibit halide complexation behaviour. Compound 4.80, forms a 1 1 polymer with bromide in the solid state in which the Hr anions perch above the Hg3 plane. The Hg—Br distances of 3.07-3.39A are considerably longer than normal Hg—Br covalent bonds (about 2.54A).61 The compound also binds SCN- with similarly long bonds as shown in Figure 4.34.60 The analogous chloride complex has a 3 2 stoichiometry suggesting a triple-decker sandwich of type [4.80 Cl 4.80 Cl 4.80]2. ... 

Mercury(II) sulfide, red, 1 19 Metal complex compounds with diolefins, 6 216... 

As mentioned earlier, the carbene ligand in our complexes shows nucleophilic character with respect to the metal fragment. Therefore, we decided to combine it with an electrophilic carbene. For this purpose we treated pentacarbonyl[methoxy(phenyl)carbene]chromium(0) with phenyl(tri-chloromethyl) mercury (85). Compounds of this kind have been studied intensively by Seyferth et al. (86) and are known as a source of dihalogeno-carbenes. The carbene complex reacted with the carbenoid compound at... 

Dithiocarbamates and thioureas are included in this section because of their useful electrochemical behavior at mercury and mercury amalgam electrodes. The formation of mercury complexes results in an easy oxidation at the mercury electrode. On the other hand, carbon electrodes are not well suited for the detection of these compounds because the oxidation occurs beyond the usual scope of carbon detector cells. 

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. 

June 24, 1922, Pfsek, then Czechoslovakia - May 30, 1994, Prague, Czech Republic) Professor of physical chemistry at Charles University, leading scientific worker of the Polarographic Institute, Prague. Koryta studied processes at the mercury jet electrode [i-ii], the electrochemical behavior of complex compounds [iii], and the effect of adsorption of electroinactive compounds on electrode processes [iv]. Later he concentrated on processes at the interface of immiscible electrolyte solutions (- interface between two immiscible electrolyte solutions, ion transfer at liquid-liquid interfaces) [v, vi]. He co-authored a textbook on electrochemistry ([vii]), which was translated into several languages. 

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