Mercury complexes 1.4- dioxane

Chlorophenyl Tellurium Trichloride1 A 100 ml one-necked flask is fitted with a reflux condenser carrying a calcium chloride drying tube and charged with 2.7 g (10 mmol) of tellurium tetrachloride, 3.5 g (10 mmol) of 4-chlorophenyl mercury chloride, and 30 ml of dry dioxane. The mixture is heated under reflux for 4 h, cooled to 20 , the mercury dichloride/dioxane complex is filtered off, and the filtrate is distilled under vacuum. The residue is recryslallized from glacial acetic acid yield 3.3 g (96%) m.p. 225°... 

Silylation of Salts of AN a-Functionalized AN 52a-c (trinitro-methane, dinitroethane, dimethyl nitromalonate, nitroacetates, etc.) can form salts, which are quite stable. It should be noted that stability of silver and mercury salts can be increased by complexation with neutral molecules (e.g., with dioxane). Hence, for these AN it is advantageous to prepare salts A, which react with halosilanes to smoothly form the corresponding SENAs 51a—C (Scheme 3.51) (174-177). 

The formed mercury dichloride is separated as a crystalline complex with dioxane. Since the starting arylmercury chlorides are easily prepared from diazonium salts, this method allows the conversion of anilines into aryltellurium trichlorides. 

No phenotellurazine was obtained when the reaction was carried out with dioxane as the solvent. The complex of tellurium tetrachloride with diphenylamine was not converted to phenotellurazine when refluxed in dioxane in the presence of catalytic amounts of mercury(II) acetate1. 

Diverse chemicals have been reported to affect measured endpoints of fish thyroidal status. These chemicals include aromatic hydrocarbons, planar halogenated aromatic hydrocarbons (dioxans, furans, coplanar PCBs), organochlorine, organophosphorus and carbamate pesticides, chlorinated paraffins, cyanide compounds, methyl bromide, phenol, ammonia, metals (aluminum, arsenic, cadmium, lead and mercury), low pH conditions, environmental steroids and a variety of pharmaceutical agents. For the following reasons their modes of action appear complex and are poorly understood16. 

Jordan and coworkers have recently prepared several ansa-bis(indenyl) compounds (AlMe2L)indenyl 2SiMe2 and 1,2- (AlMe2L)indenyl 2C2H4 (L = THF, Et20, 1,4-dioxane) by a salt metathesis route. These were reacted with M(NMe2)4 (M = Zr, Hf) to eliminate [Me2AlNMe2]2 and form ansa-metallocene complexes of bis(dimethylamido)zirconium and bis(dimethylamido)hafnium. A simple tris(indenyl)aluminum compound has been prepared by reaction of bis(indenyl) mercury with aluminum metal. ... 

Chlorination of fiiran at -40°C yields 2-chlorofuran and 2,5-dichlorofuran. Bromination with the di-oxane-Br2 complex at -5°C gives 2-bromofuran. Nitration is best carried out with fuming nitric acid in acetic anhydride at -10° to -20°C, and yields 2-nitrofuran. Pyridine-S03 or dioxane-S03 complex converts furan into furan-2-sulfonic acid and then further into furan-2,5-disulfonic acid. Alkylation and acylation are also possible. The action of mercury(II) chloride and sodium acetate in aqueous ethanol brings about mercuration of furan ... 

Fig. 7.2. Formation and dissociation rate constants of the mixed complex mercury(II) cyanide bromide as a function of the molar fraction of dioxane in a water-dioxane solvent mixture [Be 74]...

It is well known that charge-transfer complexes are excited by irradiation with UV or visible light. Since the charge-transfer complex formed during the polycondensation had an absorption maximum at 393 nm, the polycondensation of DEC with HMD in the presence or the absence of PVK was carried out in dioxane at 9 C with irradiation of UV light at a distance of 55 cm from a high pressure mercury... 

The separation of solvent effects on reactivities into constituent initial-state and transition-state effects by the use of appropriate kinetic and thermodynamic data has been successfully carried out for several organic reactions. Thus, for example, the solvolysis of t-butyl chloride and the Menschutkin reaction were treated in this manner some time ago a recent organic example is afforded by the solvolysis of isopropyl bromide in aqueous ethanol. For inorganic reactions, this approach was early used for reactions of tetra-alkyltin(iv) compounds with mercury(ii) halides. A more recent analysis of reactions of low-spin iron(n) complexes with hydroxide and with cyanide in binary aqueous mixtures was complicated by the need to make assumptions about single-ion values in such ion+ion reactions. Recent estimates of thermodynamic parameters for solvation of complexes of the [Fe(phen)3] + type are helpful in this connection. However, it is more satisfactory to work with uncharged reactants when trying to undertake this type of analysis of reactivity trends. A suitable system is provided by the reaction of [PtClaCbipy)] with thiourea. In dioxan-and tetrahydrofuran-water solvent mixtures, reactivity is controlled almost entirely... 

A more difficult situation exists when, in the free compounds, there are strong intermolecular interactions the perturbation of these interactions by complex formation can result in an increased NQI in a complex which contradicts the usual, simple prediction of an NQI reduction upon transition to a complex. Such situations are met in complexes of mercury halogenides such as HgBr2-dioxan and Hgl2-dioxan. More complete interpretation of the experimental results can be achieved if in a complex there is present a number of quadrupole nuclei this allows a comparison of shifts for each of them. In addition, there is often useful structural data available from X-ray diffraction. Finally for an estimation of a relative role of the various contributions to observable NQR frequency shifts, one can resort to theoretical calculations. 

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