Cholic acid-based fluorescent sensor for mercuric and methyl mercuric ion in aqueous solutions

Cholic acid-based fluorescent PET sensor probe 1, bearing a pair of dithiocarbamate pendants as the receptive site and anthracene moiety as the signal displaying unit, was designed and synthesized. The sensor probe not only shows high selectivity and sensitivity to Hg²⁺ in aqueous acetonitrile solution, but also responds moderately to MeHg⁺. A distinctive OFF-ON type signaling of up to 10-fold enhancement was observed for this new sensor probe toward Hg²⁺.     

Heterogeneous colorimetric sensor for mercuric salts

A novel chemical sensor for the colorimetric detection of mercuric salts is described. The sensor is based on a mesoporous nanocrystalline TiO2 film sensitised with a ruthenium dye; immersion of this film in an aqueous solution of Hg2+ results in a rapid colorimetric response, with both a high selectivity and a sub-micromolar sensitivity.     

Oxidation of 3-carene with mercuric acetate

Summary The oxidation of 3-carene with mercuric acetate was studied. The oxidative acetylation of 3-carene with mercuric acetate leads to a less complex mixture of products than oxidation with lead tetraacetate. The main products are p-mentha-l,5-dien-8-ol and, in smaller amount, p-isopropenyltoluene.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 466–475, March, 1965     

BackTitration with mercuric nitrate in alkaline medium

Summary Potentiometric back titration of excess EDTA than required to chelate with lanthanum using mercuric nitrate as the back titrant provides an excellent method for the estimation of this metal. By aid of the method amounts of lanthanum in the order of 50 g up to 60 mg were determined with high accuracy in most cases. The method is further successfully applied for analysis of pairs of La with Th, Ba, Hg^II, Mn^II, Cu, Zn, Cd, Ni, Co or Bi using a suitable precipitant or masking agent or selective P_H. NH₄F has proved to be a suitable masking agent for small amounts of lanthanum.See also Z. analyt. Chem. 169, 109 (1959).     

Reaction of 2-cyclopropylthiophenes with mercuric acetate

The reaction of 2-cyclopropylthiophene with mercuric acetate in methanol takes place only in the thiophene ring. 5-Methyl-2-cyclopropylthiophene undergoes mercuration in both the heterocyclic ring and in the three-carbon ring (the Levina reaction).Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 175–179, February, 1984.     

Formation of Liesegang rings of mercuric chromate and the effect of gel medium on the condition of mercuric chromate

Summary For the formation of well defined Liesegang rings in different gel media, it is essential to study the effect of gel medium on the condition of the insoluble salt. In case of mercuric chromate, the well defined rings were developed in agar agar and starch gel as the sol formed is coagulable by one of the reactants. In gelatin medium, a very stable sol of mercuric chromate is formed, which is coagulated by hydrochloric acid. Beautiful bands of mercuric chromate were formed in gelatin gel only in presence of hydrochloric acid.

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Zusammenfassung Zur Bildung von gut definierten Liesegang-Ringen in verschiedenen Gel-Medien ist es wesentlich, die Wirkung des Gel-Mediums auf die Bedingung des unl?slichen Salzes zu untersuchen. Im Fall von Quecksilber werden die gut definierten Ringe in Agar-Agar und St?rkegel entwickelt, wenn das gebildete Sol durch einen der beiden Reaktanten koaguliert werden kann. In Gelatine wird ein sehr stabiles Sol von Quecksilber-Chromat gebildet, welches durch Salzs?ure koaguliert wird. Sehr sch?ne Ringe von Quecksilbersulfat bilden sich in Gelatinegel nur in Anwesenheit von Salzs?ure.

     

Back titration with mercuric nitrate in alkaline medium

Summary A rapid, reliable and accurate method for the determination of trivalent chromium, based on back titrating excess EDTA solutions in the presence of chromium versenate, with mercuric nitrate in alkaline media is given. By its aid amounts of chromium in the order of 50 micro- to 15 milligrams can be determined with fair accuracy. The method is applied for analysis of binary mixtures of chromium with thorium, copper(II), bismuth or mercury(II).     

Back titration with mercuric nitrate in alkaline medium

Summary The back titration procedure making use of mercuric nitrate as back titrant for excess EDTA in alkaline media, has been successfully applied for the determination of small amounts of scandium or palladium in the order of 0.045 to 7 or 0.1 to 4mg, respectively. Simple procedures are given for the analysis of binary or ternary mixtures of scandium or palladium with some other metals, yielding results of quite reasonable accuracy.

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Zusammenfassung Scandium oder Palladium können in Mengen von 0,045–7 bzw. 0,1–4 mg bestimmt werden, wenn man mit einem Überschuß an ÄDTA versetzt und in alkalischem Medium mit Quecksilber(II)-nitratlösung zurücktitriert. Auf einfache Weise können auch binäre und ternäre Gemische von Scandium oder Palladium mit anderen Metallen mit befriedigender Genauigkeit analysiert werden.

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See also: Z. analyt. Chemie 184, 92 (1961).     

Back titration with mercuric nitrate in alkaline medium

Summary Potentiometric back titration of excess EDTA than required to chelate with gallium or indium using mercuric nitrate as the back titrant provides an excellent method for the determination of amounts of both metal ions in the order of 0.07 to 11 and 0.05 to 18 mg, respectively. The method is further successfully applied for analysis of binary and ternary mixtures of gallium or indium with some other cations using simple procedures.

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Zusammenfassung Gallium oder Indium können in Mengen von 0,07–11 bzw. 0,05 bis 18 mg bestimmt werden, wenn man mit einem überschuß an äDTA versetzt und mit Quecksilber(II)-nitratlösung potentiometrisch zurücktitriert. Auf einfache Weise können auch binäre und ternäre Mischungen von Ga oder In mit einigen anderen Kationen erfolgreich analysiert werden.

     

Cleavage of vinylic mercuric halides by aqueous acids

Isotope effects, general acid catalysis, and relative reactivities show that proton transfer to one of the unsaturated carbon atoms is rate determining for the acidolysis of unsaturated alkylmercuric halides. For compounds, R₁R₂C?CHHgX, substitution of CH₃ for H at R₁ or R₂ leads to an acceleration of a factor of ～ 30. This relatively small acceleration, the relative facility of the reactions, and the magnitude of the Br^? catalytic terms, suggests an olefin–mercuric halide complex as the product of the rate-determining step, rather than a simple carbonium ion. The Brøonsted catalysis law is obeyed with a variety of carboxylic acids, giving an ∝ of 0.69 ± 0.04, but acids of other structures give substantially deviant catalytic coefficients, in a pattern similar to that generated by other A-S_E2 reactions. The acetic acid catalytic coefficient is larger by a factor of 10² than that predicted if it were due to specific hydronium ion–general base catalysis instead of true general acid catalysis. The overall solvent isotope effect, k_H/k_D, is 2.55 ± 0.10. The competitive isotope effect, κ_H/κ_D, is 6.84 ± 0.06. Taken with a model in which the proton is transferred directly from the H₃O⁺ unit of the aquated proton to the substrate, these are sufficient to successfully predict the rate at all intermediate isotopic compositions.     

Titrimetric determination of certain mercaptans with mercuric chloride

A procedure is described for the semimicro determination of certain mercaptans, by means of their reaction with mercuric chloride. The acid liberated during the reaction is titrated with standard alkali after addition of sufficient potassium iodide to convert the surplus mercuric chloride into a stable soluble complex. The procedure has been applied to determine 0.12-1 mmole of these compounds; the results are accurate to within 0.5%.     

Back titration with mercuric nitrate in alkaline medium

Summary Small amounts of bismuth in the order of 100 g up to 25 mg were potentiometrically determined by back titration with mercuric nitrate in alkaline media. The method gives highly accurate results and is further successfully applied for analysis of pairs of bismuth together with one of the cations of calcium, copper, cadmium, zinc, manganese, nickel, lead, aluminium and lanthanum.See also Z. analyt. Chem. 161, 401 (1958); 163, 81 (1958).