Cs7Sm11[TeO3]12Cl16 and Rb7Nd11[TeO3]12Br16, the new tellurite halides of the tetragonal Rb6LiNd11[SeO3]12Cl16 structure type

The authors thank the Russian Foundation for Basic Researches for the support of this work under Grants No. 14-03-00604_a and 12-03-92604-KO_a. The X-ray study of compound II was made possible due to M.V. Lomonosov Moscow State University Programm of Development. PL thanks the University of St Andrews and EPSRC for DTA Studentships to CB and LJD.Two new rare-earth – alkali – tellurium oxide halides were synthesized by a salt flux technique and characterized by single-crystal X-ray diffraction. The structures of the new compounds Cs7Sm11[TeO3]12Cl16 (I) and Rb7Nd11[TeO3]12Br16 (II) (both tetragonal, space group I4/mcm) correspond to the sequence of [MLn11(TeO3)12] and [M6×16] layers and bear very strong similarities to those of known selenite analogs. We discuss the trends in similarities and differences in compositions and structural details between the Se and Te compounds; more members of the family are predicted.PostprintPeer reviewe

Теоретическое исследование элементарных реакций с участием молекулярного водорода и легких алканов

Review of results of quantum-chemical calculations of potential energy surfaces performed for several families of elementary reactions: 1) successive dehydrogenation of complex alanates of alkali and alkali-earth metals; 2) dissociative adsorption of hydrogen, methane and ethane molecules onto doped aluminum clusters Al@XAl11 with dopants X = B, C, Si, Ge, Li, and Ti; 3) conversion of mеthane into methanol in the presence of oxoferrylporphyrine complexes of (Fe=O)(P)(NН2) type.Обзор результатов квантовохимических расчетов поверхностей потенциальной энергии для нескольких семейств элементарных реакций: 1) последовательного дегидрирования комплексных аланатов легких щелочных и щелочноземельных металлов; 2) диссоциативного присоединения молекул водорода, метана и этана к допированным алюминидным кластерам типа Al@XAl11 с допантами X = B, C, Si, Ge, Li и Ti; 3) конверсии метана в метанол в присутствии аминовых оксоферрилпорфириновых комплексов типа (Fe=O)(P)(NН2)

New layered compounds BaFMgPn (Pn= P, As, Sb and Bi), transition-metal-free representatives of the LaOAgS structure

Four new transition metal-free pnictide representatives of the LaOAgS structure type were predicted by DFT calculations and found in the BaFMgPn (Pn = P, As, Sb and Bi) family. The compounds adopt the tetragonal space group P4/nmm with the unit cell parameters a/c 4.3097(1) angstrom/9.5032(1) angstrom, 4.3855(1) angstrom/9.5918(1) angstrom, 4.5733(1) angstrom/9.8184(1) angstrom, and 4.6359(1) angstrom/9.8599(1) angstrom, respectively. According to the DFT calculations, these new compounds are semiconductors with band gaps steadily decreasing from Pn = P (ca. 2 eV) to Pn = Bi (ca. 1 eV). The corresponding strontium fluoride and rare-earth oxide analogs are unlikely to exist and have not been observed yet. The trends of the stability within 1111 and structurally and/or chemically related compounds based on a combined consideration of geometry and DFT calculations are discussed

Dynamic and spectral mixing in nanosystems

In the framework of simple spin-boson Hamiltonian we study an interplay between dynamic and spectral roots to stochastic-like behavior. The Hamiltonian describes an initial vibrational state coupled to discrete dense spectrum reservoir. The reservoir states are formed by three sequences with rationally independent periodicities typical for vibrational states in many nanosize systems. We show that quantum evolution of the system is determined by a dimensionless parameter which is characteristic number of the reservoir states relevant for the initial vibrational level dynamics. Our semi-quantitative analytic results are confirmed by numerical solution of the equation of motion. We anticipate that predicted in the paper both kinds of stochastic-like behavior (namely, due to spectral mixing and recurrence cycle dynamic mixing) can be observed by femtosecond spectroscopy methods in nanosystems.Comment: 6 pages, 4 figure

Теоретическое исследование активационных барьеров элементарных реакций ступенчатого дегидрирования молекулы тетрааланата титана

Theoretical calculations of the potential energy surfaces along the minimum energy pathway have been performed for elementary step-wise dehydration reactions of Ti tetrahydroaluminate by using the density functional (B3LYP) and coupled cluster (CCSD(T)) methods with the 6-311++G** basis set.В рамках метода функционала плотности (B3LYP) и метода связанных кластеров (ССSD(T)) с базисом 6-311++G** выполнены расчеты поверхностей потенциальной энергии вдоль минимальных энергетических путей для элементарных реакций последовательного отрыва молекулярного водорода от тетрааланата титана

Теоретическое исследование элементарных реакций дегидрирования амминоборатных и амминоаланатных комплексов магния

Theoretical calculations of the potential energy surfaces along the minimum energy pathway have been performed for elementary step-wise dehydration reactions of ammine magnesium borohydride and alumohydride complexes Mg(MH4)2(NH3)2 and their dimers [Mg(MH4)2(NH3)2]2 (M = В и Al) by using the density functional (B3LYP) and coupled cluster (CCSD(T)) methods with the 6-311++G** basis set.В рамках метода функционала плотности (B3LYP) и метода связанных кластеров (ССSD(T)) с базисом 6-311++G** выполнены расчеты поверхностей потенциальной энергии вдоль минимальных энергетических путей для элементарных реакций отрыва молекул водорода от комплексных молекул амминоборатов и амминоаланатов магния Mg(MH4)2(NH3)2 и их димеров [Mg(MH4)2(NH3)2]2 (M = В и Al)

Теоретическое исследование активационных барьеров элементарных реакций ступенчатого дегидрирования молекул комплексных алюмо-гидридов легких металлов

Theoretical calculations of the potential energy surfaces along the minimum energy pathway have been performed for elementary step-wise dehydration reactions of molecules and ions of light-metal hydroaluminates (Li, Na, K, Mg, Ca and Zn) by using the density functional (B3LYP) and coupled cluster (CCSD(T)) methods with the 6-311++G** basis set.В рамках метода функционала плотности (B3LYP) и метода связанных кластеров (ССSD(T)) с базисом 6-311++G** выполнены расчеты поверхностей потенциальной энергии вдоль мини-мальных энергетических путей для элементарных реакций последовательного отрыва моле-кулярного водорода от комплексных молекул аланатов легких металлов (Li, Na, K, Mg, Ca и Zn)

The role of magnesium ions in the molecular mechanism of the action of fluoroquinolones

The article deals a literature review data mainly over the past 13 years (2007 – 2020) on the effect of magnesium ions on the mechanism of action of various fluoroquinolones.В статье представлен обзор литературных данных преимущественно за последние 13 лет (2007 – 2020 гг.) о влиянии ионов магния на механизм действия различных фторхинолонов