Mechanisms of 5'-O-Benzoyl-2,3'-anhydrothymidine Reactions with Nucleophiles: IV.* Kinetics and Thermodynamics of Azidation with Dimethylammonium Azide in DMF-1,4-Dioxane

The reaction of 5'-O-benzoyl-2,3'-anhydrothymidine with dimethylammonium azide in the system DMF-1,4-dioxane in the temperature range from 80 to 100°C follows the overall second-order kinetics and first-order kinetics with respect to each reactant. The activation parameters in the systems containing 30, 40, and 50 vol % of dioxane are, respectively: H 298 99, 85, and 79 kJ mol^{- 1}; S 298 -46, -83, and -101 J mol^{- 1} K^{- 1}. A refined model of the transition state for the rate-determining stage was proposed, which takes into account specific interaction with 1,4-dioxane.     

Synthesis and the structure of tribromo(7-bromobicyclo[4.1.0]hept-7-yl)germane

A general procedure was developed for the synthesis of halocyclopropylgermanes. This procedure was used for the preparation of tribromo(7-bromobicyclo[4.1.0]hept-7-yl)germane. The molecular structure was established by GLC-mass spectrometry, ¹H NMR spectroscopy, and X-ray diffraction analysis.     

Correlated coherent states and the problem of wave propagation in randomly inhomogeneous media

Radiophysics and Quantum Electronics -     

The applicability of TD-DFT methods to calculations of the electronic absorption spectrum of hexaamminoruthenium(II) in aqueous solution

The nonstationary density functional theory method (time-dependent DFT, TD-DFT) was used to theoretically estimate the frequencies and intensities of absorption bands of the complex hexaamminoruthenium(II) ion in aqueous solution. The spectrum simultaneously contained both valence (ligand-field, LF) transitions and an intense band of charge transfer to the solvent (CTTS). A comparison of the quality of the results obtained with the use of various exchange-correlation functionals was performed. The closest agreement with the experimental absorption spectrum was obtained with the use of the LC-BLYP hybrid functional with exchange potential corrections at large distances.