The adsorption properties of titanium dioxide

The adsorption properties of titanium dioxide were studied by gas chromatography. We used organic compounds from different classes, namely, n-alkanes, n-alkenes (C₆-C₈), and polar compounds (electron donors and acceptors) as test adsorbates. The differential heats of adsorption and the contributions of dispersion and specific intermolecular interaction energies were determined for the systems from the experimental retention data. The electron-donor and electron-acceptor characteristics of the ultimately hydroxylated surface of TiO₂ were evaluated.     

Why the Magnetite–Gold Core–Shell Nanoparticles Are Not Quite Good and How to Improve Them

Physics of the Solid State - The nature of the formation of a chemical bond at the magnetite–gold interface has been studied. The geometric structure and the electronic and magnetic...     

Low-frequency localized oscillations of the DNA double strand

The results of the molecular dynamic study on the low-energy elementary linear and nonlinear excitations of DNA macromolecule obtained within the framework of the coarse-grain model of the DNA double strand are presented. The characteristics of the basic states of the model agree well with the experimental parameters of both A and B conformations of the DNA double strand. The correlation between the directly calculated dispersion curves and density distribution of the frequency spectrum obtained in the simulation experiments is found. Special attention is focused on the soliton type of nonlinear localized excitations (breathers). These excitations are shown to exist in several frequency gaps in which the propagation of harmonic linear waves is prohibited. The types of motions corresponding to all calculated breathers are identified. The correlation between the two types of breathers and their analogs studied in terms of unidimensional models and treated as elementary excitations responsible for the initial stage of the opening of the DNA double strand is established.     

Antimony(III) Oxofluorides α-Sb3O2F5 and β-Sb3O2F5: Synthesis and Crystal Structures

The conditions for the synthesis of two polymorphous forms of antimony(III) oxofluoride Sb₃O₂F₅ from aqueous solutions are established. The crystal structure of a new polymorphous modification -Sb₃O₂F₅ is determined (monoclinic crystals with a = 6.9548(6) Å, b = 9.1043(7) Å, c = 20.336(2) Å, = 94.167(2)°, V = 1284.2(2) ų, Z = 8, (calcd) = 5.092 g/cm³, F(000) = 1712, space group P2₁/n) and the structure of -Sb₃O₂F₅ is refined. The geometric characteristics of crystal structures of antimony(III) oxofluorides SbOF (L- and -forms) are compared with those of Sb₃O₂F₅ (- and -forms).     

Crystal structures of tetrafluoroantimonates(III) of single and double protonated 3-amino-1,2,4-triazolium cations

Crystal structures are determined by X-ray crystallography for tetrafluoroantimonates(III) of single and double protonated 3-amino-1,2,4-triazolium cations of the composition (C₂H₅N₄)SbF₄ (I) (monoclinic: a = 4.7723(6) Å, b = 19.643(2) Å, c = 7.6974(9) Å, β = 97.239(2)°, Z = 4, Cc space group) and (C₂H₆N₄)(SbF₄)₂ (II) (monoclinic: a = 4.7617(3) Å, b = 15.512(1) Å c = 7.4365(5)Å β = 107.706(1)°, Z = 2, P2₁/n space group). The structure of I is built from complex [SbF₄]^? anions and single charged (C₂H₅N₄)⁺ cations; the structure of II is built from the same anion and double charged 3-amino-1,2,4-triazolium cation: (C₂H₆N₄)²⁺. In the structure, weak interactions Sb…F join the anions in polymeric layers [SbF₄] _n ^n? that are assembled in a 3D framework by N-H…F hydrogen bonds. The formation of the double protonated 3-amino-1,2,4-triazolium cation (C₂H₆N₄)²⁺, found in the crystal structure of II, is observed for the first time.