<Emphasis Type="Italic">O,O</Emphasis>-diphenyl <Emphasis Type="Italic">N</Emphasis>-sulfonylbenzimidoylphosphonates,a novel type of C-phosphorylated imines

A preparative method for the synthesis of first representatives of O,O-diphenyl N-sulfonylbenzimidoylphosphonates was proposed. The method involves oxidation of the corresponding α-(sulfonylamino)benzylphosphonates. The σ-constants of the N-sulfonylbenzimidoylphosphonate group were estimated by ¹⁹F NMR spectroscopy. The imidoylphosphonates obtained easily formed stable adducts at the C=N bond with P-and O-nucleophiles. Dedicated to the Corresponding Member of the Russian Academy of Sciences T. A. Mastryukova. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2567–2570, November, 2005.     

Tautomeric and conformational isomerism of natural hydroxyanthraquinones

Natural 1,5-di-, 1,4,5-tri-, and 1,4,5,8-tetrahydroxyanthraquinones and their anions and metal complexes were shown to be equilibrium mixtures of tautomers and conformers using quantum-chemical and correlation analysis of elecronic absorption spectra. Solvent effects, ionization, complexation, and the introduction and substitution of substituents were accompanied by shifts of tautomeric and conformational equilibria that determine the color of the compounds. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 224–229, May–June, 2006.     

First ionization potentials and conjugation in molecules of ethylene derivatives containing organoelemental substituents of Group IV elements

Unlike theE _HOMO energies, the first vertical ionization potentials (I ₁) of monosubstituted ethylenes dependen not only on both the inductive and resonance effects but also on the polarizability of the substituents, which can be characterized by the σ_α parameters. The σ _R ⁺ , σ _p ⁺ , and σ_α parameters for 12 silicon-, germanium-, and tin-containing groups were determined using the equations relating theI ₁ values and the σ_I, σ _R ⁺ , σ _p ⁺ and σ_α parameters of the substituents in the molecules of organic compounds. The conjugation of organoelemental substituents with the double bond is stronger than that with benzene ring; the σ _R ⁺ parameters in the ethylene and benzene series are related by a linear dependence. Translated fromIzvestiya Akademii Nauk Seriya Khimicheskaya, No. 9, pp. 1626–1631, September, 1997.