Reaction of perfluoro carbanions with mercury trifluoroacetate and trifluoromethylmercury trifluoroacetate

Conclusions The reaction of fluoroolefins and alkali metal fluorides with mercury trifluoroacetate and trifluoromethylmercury trifluoroacetate in polar aprotic solvents is a convenient method for the preparation of symmetrical and unsymmetrical bis(perfluoroalkyl)mercury compounds.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1642–1643, July, 1974.     

Promoting effect of ionic liquids on ligand substitution reactions

Ionic liquid solvents N-hexylpyridinium bistrifylimide ([C₆pyr][Tf₂N]] and 1-butyl-3-methylimidazolium hexafluorophosphate ([C₄mim][PF₆]) promoted the displacement of anionic ligands by pyridine derivatives in trans-(Ph₃P)₂Rh(CO)NO₃ to a much greater extent than did dichloromethane. Thus, addition of a slight excess of 2-fluoropyridine to trans-(Ph₃P)₂Rh(CO)NO₃ in [C₄mim][PF₆] gave a 29:71 product mixture of trans-(Ph₃P)₂Rh(CO)NO₃:[trans-(Ph₃P)₂Rh(CO)(2-fluoropyridine)][NO₃], while the ratio was 91:9 in dichloromethane.     

High-temperature transnitrilation of 2-bromocaproic acid

Chromato-mass spectrometry and IR and PMR spectroscopy were used to study the high-temperature reaction of 2-bromocaproic, 2-iodocaproic, and 2-bromo-2-phenylacetic acids with acetonitrile. The formation of anomalous transnitrilation products (capronitrile and benzyl cyanide) is a consequence of the initial conversion of 2-halo-substituted caproic and phenylacetic acids to caproic and phenylacetic acids, respectively.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1682–1684, July, 1990.     

Interaction of bis(trimethylsilyl)acetylene complex of titanocene with mercury trifluoroacetate

The reaction of the bis(trimethylsilyl)acetylene complex of titanocene Cp₂Ti(Me₃SiC₂SiMe₃) with mercury trifluoroacetate (NF₃COO)₂Hg at 20 °C in a THF medium affords titanocene bis(trifluoroacetate) Cp₂Ti(OCOCF₃)₂ and metallic mercury. The structure of Cp₂Ti(OCOCF₃)₂ was established by the analytical and spectroscopic methods and X-ray diffraction analysis.     

Electrophilic cyclization of α- and β-geranyl acetates by mercury(II) trifluoroacetate

Electrophilic cyclization of β-geranyl acetate promoted by mercury(II) trifluoroacetate leads to mixtures of α- and γ-5αH-cyclogeranyl acetate derivatives and 6α-hydroxy-5αH-and 6α-hydroxy-5βH-cyclogeranyl acetate derivatives mercurated at the C-3 atom. The ratio of the unsaturated and hydroxymercurated products depends on the reaction conditions. α-Geranyl acetate reacts with mercury(II) trifluoroacetate to give a mixture of 6α-hydroxy-5αH-and 6α-hydroxy-5βH-geranyl acetates, mercurated at C-9, with an equatorial mercurated methylene group at C-4. The mercury-containing groups in mercurated cyclogeranyl derivatives can easily be reduced or replaced by an oxygen-containing functional group; this constitutes a convenient route to polyfunctional cyclogeranyl derivatives that are difficult to obtain. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1320–1324, July, 1997.     

Rearrangement and degradation of cephalosporins and penicillins in the presence of mercury(II) trifluoroacetate

[reaction: see text] Cephalosporins and penicillins rearrange under the influence of mercury(II) trifluoroacetate in methanol to non-beta-lactam products. The mechanisms of the rearrangements are different in the two cases. Whereas the open-chain aminoacrylic acid derivative 4 is produced from cephalosporins, the oxazole 7 and the propionamide 6 derivatives are the products from penicillins.     

Promoting effect of benzene on reduction of mercury(II) salts by carbon monoxide in aqueous media

The promoting effect of benzene on the reduction of HgX₂ (where X = NO₃^? , CH₃COO^?,SO₄^2?) by carbon monoxide in aqueous media at 298 K, is demonstrated.     

Studies of transnitrilation mechanism in the presence of trifluoroacetic acid

A non-cyclic imide, an intermediate of transnitrilation, is shown to be formed through the step of unstable isoimide isomerization. The addition of a carboxy group of the acid to the cyano group has been studied. Interaction of acetonitrile with aliphatic carboxylic acids is suggested to follow a concerted but not a synchronous mechanism with prior formation of the N–H bond.

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, — — . . , , N–H.

     

Synthesis and reactions of bis(benzylchromiumtricarbonyl)mercury

Conclusion Bis(benzylchromiumtricarbonyl)mercury was synthesized by the reaction of dibenzylmercury with (NH₃)₃Cr(CO)₃inboilingdioxane. Its reaction was studied with iodine, LiAlH₄, HgCl₂, and CuCl₂.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1131–1134, May, 1982.     

Solvent effect on complexation reactions

The inclusion complexation of aromatic amines with cucurbit[6]uril (CB[6]) capped with alkali metal cations was studied spectrophotometrically. We showed that CB[6] capped with alkali metal cations forms a 1:1 inclusion complex with the aromatic amine guests (neutral organic molecules), independent of the length of guest molecules. The effects of salts on the inclusion constants of CB[6] in the presence of different alkali salts were examined and it was found that the inclusion constants increased in the order of alkali cation Cs⁺ < Na⁺ < K⁺, suggesting the interaction of amine guests with the capped alkali metal cation. Further, the structures of the inclusion complexation of aromatic amines with CB[6] were characterized by ¹H NMR measurements. Based on the results, the inclusion abilities of CB[6] capped with alkali metal cations are discussed.     

Solid state reactions in the platinum–mercury system

Thermogravimetry, Differential Scanning Calorimetry and other analytical techniques (Energy Dispersive X-ray Analysis; Scanning Electron Microscopy; Mapping Surface; X-ray Diffraction; Inductively Coupled Plasma Atomic Emission Spectroscopy and Cold Vapor Generation Atomic Absorption Spectroscopy) have been used to study the reaction of mercury with platinum foils. The results suggest that, when heated, the electrodeposited Hg film reacts with Pt to form intermetallic compounds each having a different stability, indicated by at least three mass loss steps. Intermetallic compounds such as PtHg₄, PtHg and PtHg₂ were characterized by XRD. These intermetallic compounds were the main products formed on the surface of the samples after partial removal of bulk mercury via thermal desorption. The Pt(Hg) solid solution formation caused great surface instability, attributed to the atomic size factor between Hg and Pt, facilitating the acid solution’s attack to the surface.     

Titrimetric microdetermination of inorganic or organic mercury by amplification reactions

A simple titrimetric method for estimation of 0.05-7 mg of Hg(II) is presented. The acidic sample solution is treated with a measured and excessive amount of iodide, then mercuric iodide is extracted at ph 2-3.5, and the unreacted iodide is determined iodometrically after 6- or 36-fold amplification by use of bromine water for oxidation of iodide to iodate. Periodate oxidation of excess of iodide gives 24-fold amplification. The coefficient of variation does not usually exceed 1% for above 1 mg of mercury but increases to 4% at the 0.05-mg level. The 6-fold amplification method is used for microdetermination of organically bound mercury following oxygen-flask combustion. The average absolute error for 10 determinations (3 compounds) amounted to +/-0.6%; one determination takes less than one hour.     

Transmetallation reactions of planar chiral cyclopalladated ferrocenylimines with metallic mercury

A series of optically active 2-chloromercurio-1-[1-(arylimino)ethyl] ferrocenes was synthesized by transmetallation of optically active cyclopalladated ferrocene derivatives with metallic mercury. The structure and absolute configuration of complexes Rp-4b were determined by X-ray diffraction, on the basis of which and the CD spectra the absolute configuration of other optically active compounds was ascertained.     

Solvents effect on SN2 reactions

We attempt to find out the origin of rate difference of the S_N2 reaction in the gas phase and in the aqueous solution which is about twenty orders of magnitude. To do this, we calculate the interaction energies of both reactant-complex and activated-complex of the S_N2 reaction with the hydrated water molecules and their interaction energy differences, varying the number of hydrated water molecules step by step. The calculated results show that the rate of the S_N2 reaction decreases with an increase of the number of hydrated water molecules due to the increase of the reaction barrier height and also about sixty or more water molecules are needed to explain the rate difference of the S_N2 reaction in the gas phase and solution.