GRECP/MRD‐CI calculations on the Hg atom and HgH molecule

Multireference single‐ and double‐excitation configuration interaction (MRD‐CI) calculations of transition energies for the Hg atom and spectroscopic constants for the HgH molecule are carried out with the generalized relativistic effective core potential (GRECP) method. A new selection criterium for the reference configurations is discussed. The calculated spectroscopic constants are compared with experimental data and results of calculations of other groups. Improvement of accuracy is mainly observed for bond lengths from the GRECP/MRD‐CI calculations (without applying the T = 0 correction) with respect to the results of other groups. Analysis of the quality of the approximations employed is carried out. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002     

Adsorption of 1,10-phenanthroline within a dodecanethiol monolayer: an approach to a switchable electrode surface

A simple method was used to prepare a "switchable" electrode surface by using self-assembled monolayers of dodecanethiol on a gold electrode. The dodecane-modified electrode was electrochemically inactive until the monolayer was soaked in solutions of 1,10-phenanthroline or 2,2'-bipyridine. The electroactive form of the electrode could be reverted back to the nonelectroactive form by rinsing the electrode. Surface IR results showed that both dodecanethiol and 1,10-phenanthroline exist in the mixed monolayer.     

Synthesis of pyrimidine betaines with phosphonium and cycloammonium cations

Previously undescribed pyrimidine betaines with cycloammonium and triphenylphosphonium cations were obtained. A study of the UV, IR, PMR, and mass spectra made it possible to draw a conclusion regarding the noncyclic structure of betaines stabilized by an intramolecular donor-acceptor interaction of the charge-transfer complex (CTC) type.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1687–1690, December, 1978.     

3, 3, 3-Trifluoropropyl(methyl)cyclosiloxanes

The influence of the number of 3, 3, 3-trifluoropropyl(methyl)siloxane links (Φ/Φ) in the cyclotetrasiloxanes Φ_mD_4-m, where D represents the dimethylsiloxane link and m=0–4, on the rearrangement of these compounds in acetone solution under the action of sodium siloxanolate has been studied. The rearrangement takes place with the formation of a linear polysiloxane the degradation of which yields, in addition to the initial ring, cyclosiloxanes with a different structure. The rate of rearrangement of Φ_mD_4-m and of the formation of a linear polysiloxane rises with an increase in m from 0 to 3. The equilibrium concentration of the linear polysiloxane formed from Φ_mD_4-m is inversely proportional to m. Results have been obtained on the kinetics of the formation of the cyclosiloxanes Φ_mD_n, where m=0–5, n=0–5, and m+n=3–6, in the rearrangement of the rings ΦD₃, Φ₂D₂, Φ₃D, and Φ₄. The reactivity of the siloxane links rises in the sequence ～ (CH₃)₂Si-O-Si(CH₃)₂ ～<～ (CF₃CH₂CH₂)-(CH₃) Si-O-Si(CH₃)₂ ～<(CF₃CH₂CH₂) (CH₃)Si-O-Si(CH₃) (CH₂CH₂CF₃) ～. Because of the negative inductive effect transferred through the siloxane links, the 3, 3, 3-trifluoropropyl groups strongly activate the siloxane ring with respect to nucleophiiic reagents.     

Gas-Chromatographic Determination of Butanol and Butyl Acrylate in Aqueous Solutions with the Use of Headspace Analysis

A procedure has been developed for the determination of the concentration of butanol and butyl acrylate in aqueous solutions in the range of 0.5–20 MPC. The procedure is based on static headspace gas-chromatographic analysis on a column filled with the Chromaton N-AW-HMDS sorbent containing 15 wt % of polyethylene glycol adipate with detection by a flame-ionization detector.     

Application of Liquid Crystalline NMR Solvents to a Mixture of Ketones

A series of dilute liquid crystalline solvents are used to study the effect of slight anisotropy caused by partial alignment on chemical shift and residual dipolar coupling (RDC) in small molecules. The residual dipolar couplings between protons in solutes are found to be almost independent of the local environment. It is also found that the chemical shift does not change over the concentration range observed. A linear relationship between residual dipolar coupling and liquid crystal concentration is observed at relatively low concentrations, but is severely violated at high concentrations.     

Hydrogenated azolo- and azinopyridines based on 1,5-diketones

Compounds that contain a hydrogenated azolopyridine structure are formed in the reaction of various types of 1,5-diketones with ethanolamine, o-aminophenol, o-phenylenediamine, and aroylhydrazines; compounds that include a hydrogenated azinopyridine structure were obtained by the reaction of diketones with 3-aminopropanol and anthranilic acid. The hydrocyanation and oxidation of the compounds obtained were studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 240–245, February, 1979.     

Investigation of heterocyclic quinones XVII. Oxidative amination of 6-hydroxyquinazoline

Representatives of a new class of heterocyclic quinones — quinazoline-5,6-quinones — were obtained by the oxidative animation of 6-hydroxyquinazoline, 2-phenyl-6-hydroxyquinazoline, and 4-piperidino-6-hydroxyquinazoline. 6-Hydroxyquinazolines that are not substituted in the 2 position are animated in this position during oxidation. A possible mechanism for the amination is proposed.See [1] for communication XVI.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1698–1702, December. 1971.