One-pot five-component high diastereoselective synthesis of polysubstituted 2-piperidinones from aromatic aldehydes,nitriles, dialkyl malonates and ammonium acetate

Molecular Diversity - A novel five-component diastereoselective synthesis of polysubstituted 2-piperidinones is reported. The Knoevenagel condensation–Michael addition–Mannich cascade...     

Presowing Treatment of Spring Wheat Seeds by a Pulsed Electron Beam in the Atmosphere

High Energy Chemistry - The purpose of this work is to optimize the conditions of presowing treatment of spring wheat seeds with a low-energy pulsed electron beam. The absorbed dose in wheat has...     

Synthesis and potentiometric analysis of organophosphorus metal complexones and complexonates based on 2-aminothiazole derivatives

Synthesis conditions of 4-phenyl-2-amidothiazolyl acetate and 2-thiourido-4-diethylphosphothiazole were developed, and the complexation capacity of these compounds in formation of mixed-ligand complexes was studied. The optimal conditions and thermodynamic parameters of the complexation process were determined. The potentiometric method was used to find thermodynamic parameters of the reactions of mixed-ligand complexation with copper(II) and lead(II) ions, the composition of the complexes being formed on the basis of 4-phenyl-2-aminothiazole and its phosphorylated derivatives was determined.     

Complex chromatographic determination of the adulteration of dairy products: A new approach

A new approach to complex chromatographic determination of the adulteration of dairy products was proposed, based on the determination of not only the total fatty acid composition but also the composition of the sterol fraction and the concentration of trans-isomers of fatty acids. Procedures for the chromatographic identification of low-fat dairy products were developed, including the extraction of a water-milkalcohol emulsion with a hexane-ether mixture followed by the chromatographic determination of the sterol fraction and trans-isomers.     

Study of structure and spectral characteristics of the binuclear zinc complex with (<Emphasis Type="Italic">E</Emphasis>)-2-({2-[3-(pyridin-2-yl)-1<Emphasis Type="Italic">H</Emphasis>-1,2,4-triazol-5-yl]phenylimino}methyl)phenol

A study of the structure and spectral properties of the compound (E)-2-({2-[3-(pyridin-2-yl)-1H-1,2,4-triazol-5-yl]phenylimino}methyl)phenol and its binuclear complex with zinc was carried out by the quantum-chemical calculations at a level of density functional theory. Within the framework of the time-dependent density functional theory were calculated electron spectra of both compounds, which gave good agreement with experiment, and was revealed the nature of the absorption bands in the visible and near UV region taking into account the solvent effect. Complete interpretation of the absorption bands in the infrared spectra of the complex and protonated ligand was given, and the frequency shift and changes in the intensities of IR bands of the ligand at the complex formation were analyzed.     

Specific features of the structure of a lanthanum nitrate complex with ethylenediamine

Anhydrous lanthanum nitrate and its complexes with one and two ethylenediamine molecules are calculated by the ab initio B3LYP/LANL2DZ quantum-chemical method. An ethylenediamine molecule is shown to coordinate preferentially through one amino group, and a hydrogen bond is formed between the coordinated amino and nitrato groups. An ethylenediamine complex of lanthanum nitrate is synthesized, and its composition and thermal stability are determined. The IR spectra of the ethylenediamine complex of lanthanum nitrate confirm the presence of the intramolecular hydrogen bond in this complex.     

Arylidenehydroacridines from di(3-arylidene-2-oxocyclohexyl)-methanes

The reaction of di(3-benzylidene-2-oxocyclohexyl)methane and its p-methoxy analog with primary amines results in the formation of derivatives of 4,5-diarylidenehydroacridines, whereas the reaction with o-phenylenediamine is accompanied by the elimination of one arylidene group and gives derivatives of 4-arylidenehydroacridines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1393–1395, October, 1984.     

Addition Polymerization of 5-Ethylidene-2-Norbornene in the Presence of Pd N-Heterocyclic Carbene Complexes

New high-performance catalytic systems based on Pd N-heterocyclic carbene complexes for the selective addition polymerization of 5-ethylidene-2-norbornene (ENB) were proposed. With these catalysts, polymerization can be conducted at unprecedentedly high monomer/catalyst ratio (up to 5 × 10⁵/1) and gives high-molecular-weight soluble polymers with good film-forming properties. Varying the polymerization conditions (reaction temperature, monomer and catalyst concentrations, monomer/Pd ratio) makes it possible to prepare soluble ENB-based addition polymers with specified molecular weights in reasonable yields.     

Analysis of the electronic,IR, and <Superscript>1</Superscript>H NMR spectra of conjugated oligomers based on 4,4'-triphenylamine vinylene

Two types of conjugated oligomers based on 4,4'-triphenylamine vinylene have been synthesized and characterized by the methods of IR, UV–visible, and ¹H NMR spectroscopy. The corresponding spectra have also been simulated theoretically at the density functional theory level with application of the B3LYP and BMK hybrid exchange-correlation functionals. A comparative analysis of the experimental and theoretical spectra of polymers and oligomers has revealed regularities of the manifestation of spectral signals depending on the conjugation chain length and the presence of a substituent in the triphenylamine core. It has been established, in particular, that the absolute intensity of IR bands satisfies a linear dependence with increase in the degree of polymerization; however, no frequency shift is observed at the same time. The position of the main peak in electron absorption spectra demonstrates the bathochromic shift with an increase in the oligomeric chain length due to the narrowing of the energy gap between the boundary molecular orbitals. Based on the theoretical estimation of the hydrogen atoms chemical shifts, the signals of various protons types in the strongly broadened experimental ¹H NMR spectra of the bis-(4-iodine phenyl)-phenylamine and N,N-bis-(4-iodine phenyl)-4'-(phenylethynyl)-phenylamine polymerization products have also been identified.