Reaction of cyclopentadienyllutetium anthracenide with azobenzene. Synthesis and molecular and crystal structure of the binuclear complex [C5H5(THF)Lu(μ−η2:η2−PhN—NPh)]2(THF)2 and its dynamic behavior in solution

The reaction of the cyclopentadienyllutetium anthracenide, C₅H₅Lu(C₁₄H₁₀)²⁻(THF)₂ (1), with azobenzene yielded the [C₅H₅(THF)Lu(μ−η²:η²−PhN—NPh)]₂(THF)₂ (2) binuclear complex. The structure of the reaction product was established by X-ray structural analysis. The dynamic behavior of complex2 in a THF-d₈ solution was studied by¹H NMR spectroscopy in the temperature range of 265–330 K. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1667–1671, September, 1997.     

1.5-Diaza-3.7-diphospha-cyclooctane

The alkyl (aryl)-bishydroxymethylphosphines react with primary amines to give the title compounds. With optically active amines optically active phosphines are formed.     

An in vitro Study on Transition from NO-Hemoglobin to Methemoglobin： Oxygen Effect

The nitrosyl-hemoglobin (HbNO) is the carrier of nitric oxide (NO) which is the important messenger molecule displaying multiple physiologic and pathophysiologic roles. However it is still not clear for the fate of HbNO molecules during the venous-arterial transit. In this letter, the HbNO transition in vitro was studied by using the electron paramagnetic resonance (EPR) spectra. It was found that HbNO molecules were stable when oxygen did not exist in the system but not stable in aerobic conditions. The absorption spectra further revealed that the methemoglobin (metHb) was the product of HbNO in aerobic environment, showing that the HbNO changed to metHb when there were enough oxygen molecules in the system.     

Reactions on a surface. 1. Condensation of 3-methyl-3-buten-1-ol with carbonyl compounds on SiO2 and Al2O3

3-Methyl-3-buten-1-ol reacts with various aldehydes and ketones on silica gel and Al₂O₃ surfaces in the absence of solvents and conventional catalysts for this reaction to form derivatives of di- and tetrahydropyrans.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1326–1328, October, 1989.     

Synthesis of indole analogs of tolan

A method for the preparation of indole analogs of tolan, viz., indolylphenylacetylene and di-indolylacetylene, from indolyl benzyl ketone and indolyl skatyl ketone, respectively, by reaction with a Vilsmeier—Haack reagent was developed. The synthesis of indolyl skatyl ketone and 3-(3-indolyl)-3-chloro-2-phenyl-2-propen-1-al was realized.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 956–958, July, 1980.     

The viscosity and density of the methanol + n-nonane, ethanol + n-nonane, and ethanol + n-decane systems

This work presents the results obtained in measurements of the kinematic viscosity and density of the methanol-n-nonane, ethanol-n-nonane, and ethanol-n-decane systems at various temperatures and low n-alkane concentrations (within the concentration range of miscibility). The dynamic viscosities of these systems at 298.15 K were calculated according to free volume theory. The results substantiated the existence of an anomaly in the behavior of viscosity of the methanol-n-nonane system (positive Δlnη values) and its absence for the ethanol-n-alkane systems.     

Kinetics of zinc and cadmium dissociation of metallothionein in the presence of chelating agents

The dissociation kinetics of metal ions from native metallothionein (Cd₅Zn₂-MT) of rat liver has been studied in the presence of external ligands including amino acids, peptide and polyamino polycarboxylic acids at 25°C. The study shows that the solution pH affects the metal dissociation process. Different ligands present different multiphasic kinetics. The possible mechanism of metal dissociation from metallothionein has been proposed.     

An adiabatic local model for the internal structure of charge-transfer excitons: Dimers and trimers

In charge-transfer crystals, the exciton-phonon interaction significantly influences the internal structure of charge-transfer excitons (CTEs). The formation of CTE dimers and trimers is considered in an adiabatic non-centrosymmetric model which includes phonon dispersion. Changes of lattice frequencies near the CTE are analysed.     

Alkoxy compounds XIX. The stereoisomerism of some 2, 5-dialkyl-5-α-alkoxyethyl-1, 3-dioxanes

Using PMR spectra and GL chromatograms, it is shown that 2,5-di methyl-, 2-isopropyl-5-ethyl-, 2, 5-diisopropyl-5-α-isopropoxyethyl-1, 3-dioxane are mixtures of isomers. Efficient columns are used to fractionate these mixtures into the individual isomers, purities being checked by GLC. From PMR spectra and dipole moments it was concluded that the low-boiling isomers of the stereoisomeric dioxanes are trans forms with chair configuration, while the high-boiling isomers are cis, and have the unsymmetrical boat-shaped configuration.     

Specific Features of the Adsorption and Nuclear Magnetic Relaxation of Water Molecules in Active Carbons. 1. Relation between the Spin-Spin Relaxation of Adsorbed Water Molecules and Structural Parameters of Microporous Active Carbons

Relation between the spin-spin nuclear magnetic relaxation time T ₂ of adsorbed water molecules and parameters of microporous structure of carbon adsorbents is disclosed. The pattern of dependences of T ₂ on the relative pressure and the number of water molecules per one primary adsorption site (PAS) is governed by the pore sizes and the number and nature of PASs. At a complete micropore filling, the T ₂ value depends on the volume density of PASs in active carbons. In the absence of PASs in the micropores, T ₂ is equal approximately to 21 ms. The larger the volume density of PASs, the smaller the number of water molecules per one PAS at the complete filling of micropores; i.e., the looser the packing of water molecules. The results of studying active carbons by the pulsed ¹H NMR method agree well with the data of the adsorption method.