Stability of dibromo-dipyrromethene complexes coordinated with B, Zn, and Cd in solutions of various acidities

The spectral luminescent properties of dipyrromethenates halogenated with bromine on both ends of the long axis and coordinated using boron fluoride, zinc, or cadmium in neutral ethanol and acidified with hydrochloric acid solutions were studied. The constants of the acid–base equilibrium of the complexes in the proton-donor solvents in the ground and excited states was determined. The mechanisms of complex protonation were discussed, depending on the structure of the compounds. The electronic structures of the neutral and protonated compounds were modeled and analyzed based on the quantum-chemical method. The structures and spectral-luminescence properties were calculated using the SMD model of ethanol solvent using the TD-DFT theory with the B3LYP functional and the composite def2-SVP/def2-TZVP/def2-TZVPP_ECP basis sets, depending on the atomic number of the elements

Phase equilibria and thermodynamic properties of oxide systems on the basis of rare earth, alkaline earth and 3d-transition (Mn, Fe, Co) metals. A short overview of

Review is dedicated studies of phase equilibria in the systems based on rare earth elements and 3d transition metals. It’s highlighted several structural families of these compounds and is shown that many were found interesting properties for practical application, such as high conductivity up to the superconducting state, magnetic properties, catalytic activity of the processes of afterburning of exhaust gases, the high mobility in the oxygen sublattice and more

Photonics of halogenated zinc(II) and cadmium(II) dipyrromethene complexes

This article compares spectroscopic properties of the series of dipyrromethene dyes, namely their complexes of boron (III), zinc(II) and cadmium(II) with the halogenated ligands of the same structure. Absorption and emission spectra, lifetimes of long-lived emission and quantum yields of luminescence were studied as the functions of molecular structure of dipyrromethene complexes. The role of the position and nature of a substituent in a ligand, polarity of a solvent and temperature of media were also investigated. The studies demonstrate that replacing the central atom boron(III) by zinc(II) decreases the fluorescence quantum yield, indicating the increased role of non-radiative processes in excitation energy deactivations such as intersystem crossings. In addition, according to the heavy atom effect, the efficiency of intersystem crossings in halogen-substituted zinc(II) and cadmium(II) dipyrromethene complexes is higher than in the corresponding boron fluoride dipyrromethenes (BODIPY), which leads to increase in phosphorescence at low temperatures (frozen solutions). The obtained results make it possible to carry out further investigations of potential sensory properties that are required for systematic use of halogenated dipyrromethene complexes for the creation of modern optical oxygen sensors and singlet oxygen photosensitizers for photodynamic therapy or photocatalytic oxidative reactions

Problem of Sources in Researching V.N. Khitrovo’s Biography

Through their work, the author examines some of the problems of studying sources while researching the biography of famous Russian statesman V.N. Khitrovo (1834-1903), who played an important role in shaping the Middle East foreign policy of the Russian Empire. While in the region, he made a great contribution to the protection of Orthodoxy and Orthodox pilgrims in the Holy Land, including the development of education of the Arab population of Palestine and Syria, and promoting the spread of Orthodox education. In order to reconstruct the biography of V.N. Khitrovo, sources of various nature and origin were identified and classified. There has been conducted for the first-time analysis of materials from the private collection of V.N. Khitrovo stored in the Department of Manuscripts of the Russian State Library; on their basis, the role of V.N. Khitrovo as a specialist in the field of genealogy is revealed within the text. The materials on the history of the Khitrovo family collected by him make it possible to most fully present the history of the family and its role in the development of the future statesman and organizer of science. There was used a wide range of unpublished archival documents containing material important for the reconstruction of V.N. Khitrovo’s biography. Above all, it is the correspondence of widow S.D. Khitrovo with bibliographer and literary critic S.I. Ponomarev. In addition, for the first time, the authors have collected obituary materials, a large amount of reference literature published in Russia in the second half of the XIX - early XX centuries, published official sources and documents of private origin, which have allow the researchers to begin supplementing, clarifying and correcting the information and facts from V.N. Khitrovo’s biography

Crystal structure and oxygen nonstoichiometry of oxides in the Ba-Me-Me’-Y-O (Me, Me’=Co, Fe) system

Polycrystalline BaМe1-xYxO3-δ(Me=Co, Fe) samples were synthesized by a conventional route and glycerol-nitrate technique. According XRD patterns of single phase solid solutions BaCo1-xYxO3-δ (0.1≤x≤0.4) and BaFe0.9-yY0.1CoyO3-δ (0.05≤y≤0.15) were indexed using Pm3m space group. The unit cell parameters were refined using Rietveld full-profile analysis. Oxygen non-stoichiometry of these solid solutions was measured by means of thermogravimetric technique within the temperature range 298-1273 K in air.The work was supported under financial support from RFBR № 13-03-00958 and Ministry of Science and Education of Russian Federation within the limits of the Federal target program "Scientific and scienceeducational cadres of innovative Russia for 2009-2013"