Vol 471, No 1 (2016)

For the first time, nonempirical modeling of water clusters composed of several fused molecular rings supplemented with the theoretical analysis of quantum states of the systems provided grounds for clarifying the conditions when consistent shifts of bridge protons within one structural ring promoted by the contraction of the oxygen skeleton can repeatedly cause the formation of H₃O⁺ and OH^– ions.

The products resulting from the reaction of TiF₄ with Ph₂P(O)(CH₂)₂C(O)Me (L') in CH₂Cl₂ have been studied by ¹⁹F{¹H} and 31P{¹H} NMR spectroscopy. At a twofold excess of L', solution contains cis-TiF₄(L')2 (>90%), trans-TiF₄(L')₂, and fac-[TiF₃L₃']⁺, where L' is coordinated via the P=O group, as well as the dimer [(Ti₂F₇L'₂)₂]+, where L' is coordinated through the P=O and C=O groups. An equimolar solution contains dimeric and polynuclear complexes containing moieties with three terminal cis fluorine ions, while the other coordination sites are occupied by the P=O groups and F^– bridges. At a twofold excess of TiF₄, ligand L' coordinates via the P=O and C=O groups and behaves as a bridge along with F^– ions. Thermodynamic stability of the structures of the TiF₄L'₂ isomers and the structure of [(µ-F)(µ-L')₂(TiF₃)₂]⁺ has been calculated.

A relation between the quadrupole coupling constant e²Qq_zz and asymmetry parameter η has been found for a series of meta-substituted iodobenzene derivatives. The relationships e²Qq_zz(η) for electrondonor and electron-acceptor substituents have the same form but different numerical values of parameters. The average time of full electron transfer via tunneling has been evaluated.

The results of isobutanol conversion on micro-mesoporous composite MFI/MCM-41 synthesized using microwave irradiation were reported. It was shown that, unlike other described isobutanol conversion catalysts, this catalyst makes it possible to produce a hydrocarbon product containing a significant amount of aromatic hydrocarbons at low benzene content and also to avoid the undesirable formation of oxygen-containing products.

Composite materials of the ZrO₂–fluorohydroxyapatite (FHA)–titanium nitride (TiN) system have been synthesized and studied. In the course of sintering even in a protective inert medium, the reaction between the components begins at 700°C to give calcium titanates, titanium oxides, and oxygen-deficient zirconia compounds. As a result of working through the procedure of synthesis of ultrafine powders and selecting sintering regimes, including the hot-pressing method, dense composite materials of the FHA–ZrO₂ system containing TiN were obtained with a bending strength of up to 273 MPa and a crack resistance of up to 3.3 MPa m^1/2.