Reduction of Hg(II) salts in aqueous acidic solutions by SO2

Kinetic studies of the reduction of Hg(II) salts in aqueous acidic solutions by SO₂ in mild conditions have revealed that SO₂ quantitatively reduces Hg(II) to metal in the examined HClO₄ concentration range (2–8M^–1).

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Hg(II) . , HClO₄ (2–8 .^–1) SO₂ Hg(II) .

     

The structure of karakoline

Summary We have isolated from the tubers ofAconitum karakolicum collected in the Kirghiz SSR, Kungei Alatau range, songorine, napelline, a base with mp 159–160°C, and the new alkaloids karakoline and a base with mp 222–224°C.The results of a study of the chemical reactions and spectral characteristics of karakoline have shown that it consists of a lycoctonine skeleton with N-ethyl and C₄-methyl groups, hydroxyls at C₁, C₈, and C₁₀ and a methoxy group at C₁₅.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 199–205, March–April, 1973.     

Heterylimidazoles IV. Homolytic dissociation of hexaaryldimidazolyls and their heterocyclic analogs

The rate constants and activation energies for homolytic dissociation of 2,2-di[ ()-naphthyl]-, 2,2-diquinolinyl-, and 2,2-di(9-acridinyl)-4,4,5,5-tetraphenyldiimidazolyls in toluene in the presence of,-diphenyl--picrylhydrazine were determined. The degrees of dissociation of the diimidazolyls were found. The effect of substituents on the stability of imidazolyl radicals is discussed.See [1] for communication III.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1536–1539, November, 1974.     

Synthesis and characterization of chitosan-graft-polycaprolactone copolymers

The graft copolymers of chitosan with polycaprolactone (PCL) were prepared through a protection-graft-deprotection route using phthaloylchitosan as intermediate. PCL macromonomers terminated with isocyanate groups reacted with hydroxyl groups of phthaloyl-protected chitosan regioselectively, and then phthaloyl groups were deprotected to give the free amino groups. The graft reaction was carried out in homogeneous system and yielded copolymers with high grafting content due to solubilization. FTIR, NMR and XRD were detected to characterize the resultant chitosan-graft-PCL copolymers.     

Electron energy loss studies of room-temperature co adsorption on Cu(100) induced by electron or ion irradiation

A custom-built multi-technique portable spectrometer was used to study the vibrational (and electronic) excitations associated with the “anomalous” CO adsorption recently observed on clean and oxidized Cu(100) surfaces at room temperature. Results from the electron energy loss (and thermal desorption) experiments have provided strong evidence for in-situ CO production induced by low-energy electron or ion irradiation of CO or C₂H₄ on Cu(100). In particular, the C-O vibrational stretch frequency for the room-temperature CO adsorption was found to be red-shifted by 9 meV from its nominal position (259 meV) and could be observed even at temperature as high as 420 K. Several plausible mechanisms involving coadsorbate interactions with CO on metal surfaces have been discussed. A direct interaction model involving partial bonding between CO, adsorbed on an atop site, and a coadsorbed O atom in a four-fold hollow site was found to be adequate in explaining the observed red shift and the apparent stabilization of CO on Cu(100) at room temperature.     

Electronic Structure of Substituted Magnesium Malonates and Malonic Aldehyde Dianion Associates

Ab initio calculations using a molecular pseudopotential and an all-electron approximation have been carried out with various basis sets for Mg complexes and for dianions of malonic aldehyde and its imino and chloro derivatives. The valence levels are reproduced most adequately, whereas the atomic charges and bond characteristics depend heavily on the basis used. Employing a pseudopotential does not change the quality of the electronic characteristics of the system, slightly increasing the existing charge separation. The Cl atom in the -position is involved in -conjugation of the dicarbonyl cycle, causing antibonding in the dianion. Introduction of Mg considerably increases the mesomeric effect of Cl and electron density on the N and O atoms, slightly changing the charges on the carbon atoms. According to the calculations, the Mg–O and Mg–N bonds are slightly covalent. The metal AO is not included in the -system of the ring.     

Hydrolysis of 1,2-disubstituted imidazolines in aqueous media

The kinetics of hydrolysis of 1,2-disubstituted imidazolines in aqueous media was studied (pH 2.0—12.5, T = 25—90 °C) by UV spectroscopy. The hydrolysis products were identified. The introduction of a branched substituent into position 2 of the imidazoline ring increases the hydrolytic stability of the compounds. The effect of the pH on the hydrolysis rate of imidazolines is discussed.     

Quantum-Chemical Study of Methyl Phenyl Sulfide

Steric and electronic structure of the methyl phenyl sulfide molecule was studied by nonempirical quantum-chemical methods. The calculations were performed by the B3LYP and MP2 procedures with account taken of electronic correlation using extended 6-311++G(3d,p) basis sets. The use of a balanced method and basis set allowed us to avoid discrepancy between the experimental and calculated data reported by other authors. The results confirmed coplanar orientation of the CÄSÄC fragment and the benzene ring, which follows from most experimental studies.